225 results on '"Rodney J. Croft"'
Search Results
2. Effect of ambient lighting on frequency dependence in transcranial electrical stimulation-induced phosphenes
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Ian Evans, Stephen Palmisano, and Rodney J. Croft
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Medicine ,Science - Abstract
Abstract Inconsistencies have been found in the relationship between ambient lighting conditions and frequency-dependence in transcranial electric stimulation (tES) induced phosphenes. Using a within-subjects design across lighting condition (dark, mesopic [dim], photopic [bright]) and tES stimulation frequency (10, 13, 16, 18, 20 Hz), this study determined phosphene detection thresholds in 24 subjects receiving tES using an FPz-Cz montage. Minima phosphene thresholds were found at 16 Hz in mesopic, 10 Hz in dark and 20 Hz in photopic lighting conditions, with these thresholds being substantially lower for mesopic than both dark (60% reduction) and photopic (56% reduction), conditions. Further, whereas the phosphene threshold-stimulation frequency relation increased with frequency in the dark and decreased with frequency in the photopic conditions, in the mesopic condition it followed the dark condition relation from 10 to 16 Hz, and photopic condition relation from 16 to 20 Hz. The results clearly demonstrate that ambient lighting is an important factor in the detection of tES-induced phosphenes, and that mesopic conditions are most suitable for obtaining overall phosphene thresholds.
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- 2022
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3. Mobile phone carrying locations and risk perception of men: A cross-sectional study
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Berihun M. Zeleke, Christopher Brzozek, Chhavi Raj Bhatt, Michael J. Abramson, Frederik Freudenstein, Rodney J. Croft, Peter M. Wiedemann, and Geza Benke
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Medicine ,Science - Abstract
Little was known about the relationship between carrying mobile phone handsets by men and their risk perception of radiofrequency-electromagnetic field (RF-EMF) exposure due to carrying handsets close to the body. This study aimed to determine where men usually carried their handsets and to assess the relationship to risk perception of RF-EMF. Participants completed a self-administered questionnaire about mobile phone use, handset carrying locations, and levels of risk perception to RF-EMF. Data were analysed using linear regression models to examine if risk perception differed by mobile phone carrying location. The participants were 356 men, aged 18–72 years. They owned a mobile phone for 2–29 years, with over three quarters (78.7%) having a mobile phone for over 20 years. The most common locations that men kept their handsets when they were ‘indoors’ were: on a table/desk (54.0%) or in close contact with the body (34.7%). When outside, 54.0% of men kept the handset in the front trouser pocket. While making or receiving calls, 85.0% of men held their mobile phone handset against the head and 15.0% either used earphones or loudspeaker. Men who carried their handset in close contact with the body perceived higher risks from RF-EMF exposure compared to those who kept it away from the body (p
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- 2022
4. Temperature Rise for Brief Radio-Frequency Exposure Below 6 GHz
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Sachiko Kodera, Akimasa Hirata, Daisuke Funahashi, Soichi Watanabe, Kari Jokela, and Rodney J. Croft
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Biological effects of radiation ,dosimetry ,product safety engineering ,radiation safety ,standardization ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
In international guidelines for human protection from radio-frequency (RF) electromagnetic fields, the specific absorption rate (SAR) averaged over 6 min and 10 g of tissue is used as a physical quantity to prevent excess local temperature rise. The resultant SAR restriction has been set to avoid potential adverse health effects due to the temperature elevation resulting from RF energy absorption. In the public consultation version of the upcoming ICNIRP RF guidelines (July 10, 2018), a specific absorption (SA) limit was set to avoid heating from brief exposures (shorter than 6 min). However, to the best of our knowledge, no prior research has evaluated the temperature rise for single/multiple pulses with energy equivalent to the 6-min exposure SAR restriction for continuous waves. This paper computed the temperature rise for brief pulse exposures based on bioheat computations. We first confirmed that the peak temperature rise for a pulse with SA corresponding to occupational exposure exceeds the steady-state temperature rise for temporally uniform continuous wave exposure. We then proposed the SA limit from a regression curve that is dependent on the duration of brief exposure to RF pulse(s). The temperature rise in a multilayer cube and an anatomical human model were also computed for exposures to multiple pulses. The temperature rise from multiple pulses satisfying the formula was found to be below the relevant threshold level. The SA based on this regression curve can be used as a metric to prevent excess temperature rise for different brief exposure scenarios below 6 min.
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- 2018
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5. Use of mobile and cordless phones and change in cognitive function: a prospective cohort analysis of Australian primary school children
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Chhavi Raj Bhatt, Geza Benke, Catherine L. Smith, Mary Redmayne, Christina Dimitriadis, Anna Dalecki, Skye Macleod, Malcolm R. Sim, Rodney J. Croft, Rory Wolfe, Jordy Kaufman, and Michael J. Abramson
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Cognitive function ,Cordless phone use ,Mobile phone use ,Primary school children ,Industrial medicine. Industrial hygiene ,RC963-969 ,Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background Some previous studies have suggested an association between children’s use of mobile phones (MPs)/cordless phones (CPs) and development of cognitive function. We evaluated possible longitudinal associations between the use of MPs and CPs in a cohort of primary school children and effects on their cognitive function. Methods Data on children’s socio-demographics, use of MPs and CPs, and cognitive function were collected at baseline (2010–2012) and follow-up (2012–2013). Cognitive outcomes were evaluated with the CogHealth™ test battery and Stroop Color-Word test. The change in the number of MP/CP voice calls weekly from baseline to follow-up was dichotomized: “an increase in calls” or a “decrease/no change in calls”. Multiple linear regression analyses, adjusting for confounders and clustering by school, were performed to evaluate the associations between the change in cognitive outcomes and change in MP and CP exposures. Results Of 412 children, a larger proportion of them used a CP (76% at baseline and follow-up), compared to a MP (31% at baseline and 43% at follow-up). Of 26 comparisons of changes in cognitive outcomes, four demonstrated significant associations. The increase in MP usage was associated with larger reduction in response time for response inhibition, smaller reduction in the number of total errors for spatial problem solving and larger increase in response time for a Stroop interference task. Except for the smaller reduction in detection task accuracy, the increase in CP usage had no effect on the changes in cognitive outcomes. Conclusion Our study shows that a larger proportion of children used CPs compared to MPs. We found limited evidence that change in the use of MPs or CPs in primary school children was associated with change in cognitive function.
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- 2017
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6. Mismatch Negativity and P50 Sensory Gating in Abstinent Former Cannabis Users
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Samantha J. Broyd, Lisa-marie Greenwood, Hendrika H. van Hell, Rodney J. Croft, Hannah Coyle, Ben Lee-Bates, Juanita Todd, Stuart J. Johnstone, Patricia T. Michie, and Nadia Solowij
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Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Prolonged heavy exposure to cannabis is associated with impaired cognition and brain functional and structural alterations. We recently reported attenuated mismatch negativity (MMN) and altered P50 sensory gating in chronic cannabis users. This study investigated the extent of brain functional recovery (indexed by MMN and P50) in chronic users after cessation of use. Eighteen ex-users (median 13.5 years prior regular use; median 3.5 years abstinence) and 18 nonusers completed (1) a multifeature oddball task with duration, frequency, and intensity deviants and (2) a P50 paired-click paradigm. Trend level smaller duration MMN amplitude and larger P50 ratios (indicative of poorer sensory gating) were observed in ex-users compared to controls. Poorer P50 gating correlated with prior duration of cannabis use. Duration of abstinence was positively correlated with duration MMN amplitude, even after controlling for age and duration of cannabis use. Impaired sensory gating and attenuated MMN amplitude tended to persist in ex-users after prolonged cessation of use, suggesting a lack of full recovery. An association with prolonged duration of prior cannabis use may indicate persistent cannabis-related alterations to P50 sensory gating. Greater reductions in MMN amplitude with increasing abstinence (positive correlation) may be related to either self-medication or an accelerated aging process.
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- 2016
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7. Acute effects of Δ9-tetrahydrocannabinol and cannabidiol on auditory mismatch negativity
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Rodney J. Croft, Patricia T. Michie, Samantha J. Broyd, Juanita Todd, Hendrika H van Hell, Alison L Jones, Robin M. Murray, Nadia Solowij, and Lisa-Marie Greenwood
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Pharmacology ,biology ,business.industry ,organic chemicals ,Mismatch negativity ,biology.organism_classification ,medicine.disease ,Placebo ,behavioral disciplines and activities ,Endocannabinoid system ,Schizophrenia ,Endophenotype ,mental disorders ,Medicine ,NMDA receptor ,Cannabis ,business ,Cannabidiol ,psychological phenomena and processes ,medicine.drug - Abstract
Rationale Mismatch negativity (MMN) is a candidate endophenotype for schizophrenia subserved by N-methyl-D-aspartate receptor (NMDAR) function and there is increasing evidence that prolonged cannabis use adversely affects MMN generation. Few human studies have investigated the acute effects of cannabinoids on brain-based biomarkers of NMDAR function and synaptic plasticity. Objectives The current study investigated the acute effects of Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) alone and in combination on the mismatch negativity (MMN). Methods In a randomised, double-blind, crossover placebo-controlled study, 18 frequent and 18 less-frequent cannabis users underwent 5 randomised drug sessions administered via vaporiser: (1) placebo; (2) THC 8 mg; (3) CBD 400 mg; (4) THC 8 mg + CBD 4 mg [THC + CBDlow]; (5) THC 12 mg + CBD 400 mg [THC + CBDhigh]. Participants completed a multifeature MMN auditory oddball paradigm with duration, frequency and intensity deviants (6% each). Results Relative to placebo, both THC and CBD were observed to increase duration and intensity MMN amplitude in less-frequent users, and THC also increased frequency MMN in this group. The addition of low-dose CBD added to THC attenuated the effect of THC on duration and intensity MMN amplitude in less-frequent users. The same pattern of effects was observed following high-dose CBD added to THC on duration and frequency MMN in frequent users. Conclusions The pattern of effects following CBD combined with THC on MMN may be subserved by different underlying neurobiological interactions within the endocannabinoid system that vary as a function of prior cannabis exposure. These results highlight the complex interplay between the acute effects of exogenous cannabinoids and NMDAR function. Further research is needed to determine how this process normalises after the acute effects dissipate and following repeated acute exposure.
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- 2021
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8. Do Mobile Phones Affect Sleep? - Investigating Effects of Mobile Phone Exposure on Human Sleep EEG.
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Andrew W. Wood, Sarah Loughran, Rodney J. Croft, Con Stough, and Bruce Thompson
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- 2008
9. A Letter to the Editor Regarding a 'Health Matters' Article [Speaker's Corner]
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Kenneth R. Foster, Chung-Kwang Chou, and Rodney J. Croft
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Radiation ,Electrical and Electronic Engineering ,Condensed Matter Physics - Published
- 2022
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10. The Alpha Band of the Resting Electroencephalogram Under Pulsed and Continuous Radio Frequency Exposures.
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Nicholas Perentos, Rodney J. Croft, Ray J. McKenzie, and Irena Cosic
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- 2013
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11. Wi-fi related radiofrequency electromagnetic fields (RF-EMF): a pilot experimental study of personal exposure and risk perception
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Rodney J. Croft, Michael J. Abramson, Chhavi Raj Bhatt, Christopher Brzozek, Berihun M. Zeleke, Peter M. Wiedemann, Frederik Freudenstein, and Geza Benke
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Risk perception ,animal structures ,Environmental Engineering ,genetic structures ,Health, Toxicology and Mutagenesis ,media_common.quotation_subject ,Applied psychology ,010501 environmental sciences ,01 natural sciences ,Applied Microbiology and Biotechnology ,03 medical and health sciences ,0302 clinical medicine ,Perception ,030212 general & internal medicine ,Exposure measurement ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology ,media_common ,Quality of Life Research ,Public Health, Environmental and Occupational Health ,Pollution ,Personal exposure ,Radiofrequency-electromagnetic fields ,Psychology ,Wi-fi ,Research Article - Abstract
The impact of providing people with an objectively measured personal radiofrequency electromagnetic fields (RF-EMF) exposure information on the risk perception of people is not well understood. We conducted an experimental study, among three groups of participants, to investigate the risk perception of people towards RF-EMF from Wi-Fi sources (ISM 2.4 GHz) by providing participants with either basic text, precautionary information, or a summary of their personal RF-EMF exposure measurement levels. Participants provided with personal RF-EMF exposure measurement information were more confident in protecting themselves from RF-EMF exposure, compared to those provided with only basic information. Nonetheless, neither the exposure perception nor the risk perception of people to Wi-Fi related RF-EMF differed by the type of information provided. The measured Wi-Fi signal levels were far below international exposure limits. Furthermore, self-rated levels of personal RF-EMF exposure perception were not associated with objectively measured RF-EMF exposure levels. Providing people with objectively measured information may help them build confidence in protecting themselves from Wi-Fi related RF-EMF exposure.
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- 2021
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12. Retinal and Cortical Contributions to Phosphenes During Transcranial Electrical Current Stimulation
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Ian D Evans, Stephen Palmisano, and Rodney J. Croft
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Adult ,Male ,Physiology ,Phosphenes ,Biophysics ,Stimulation ,02 engineering and technology ,Transcranial Direct Current Stimulation ,Retina ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Electrical current ,Cortex (anatomy) ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Visual Cortex ,business.industry ,020206 networking & telecommunications ,Retinal ,General Medicine ,Phosphene ,medicine.anatomical_structure ,Visual cortex ,chemistry ,Female ,Occipital lobe ,business ,Neuroscience - Abstract
It is generally believed that the phosphenes induced by transcranial electric current stimulation (tECS) are a product of retinal activation, even when electrode placement is directly over the primary visual cortex. However, the origins of these tECS-induced phosphenes have not yet been conclusively determined. In this study, phosphene detection thresholds using an FPz-Oz montage were compared with those from (i) an Oz-Cz montage to determine whether prefrontal regions, such as the retina, contribute to phosphenes and (ii) an FPz-Cz montage to determine whether the visual cortex in the occipital lobe contributes to phosphenes. Twenty-two participants received transcranial current stimulation with each of these montages (as well as a T3-T4 montage included for exploratory purposes) at 6, 10, 16, 20, 24, 28, and 32 Hz. To estimate differences in current density at the retina and occipital lobe across montages, modeling of current density at phosphene thresholds was measured across 20 head models. Consistent with the proposal that tECS-induced phosphenes are generated in the retina, increasing current density near the retina (FPz-Oz relative to Oz-Cz montage) reduced phosphene thresholds. However, increasing current density near the occipital cortex (FPz-Oz relative to FPz-Cz montage) also reduced phosphene thresholds while also requiring less current density at the retina according to the modeling estimates. This suggests that tECS of this occipital cortex also contributed to phosphene perception. © 2020 Bioelectromagnetics Society.
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- 2021
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13. Hyperthermia, but not dehydration, alters the electrical activity of the brain
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Benjamin J. Haberley, David J. R. Hoyle, Rodney J. Croft, Anne M. J. van den Heuvel, and Nigel A.S. Taylor
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Adult ,Male ,Hyperthermia ,medicine.medical_specialty ,Brain electrical activity ,Fever ,Physiology ,Alpha (ethology) ,Electroencephalography ,Body Temperature ,03 medical and health sciences ,0302 clinical medicine ,Heart Rate ,Physiology (medical) ,Internal medicine ,medicine ,Humans ,Orthopedics and Sports Medicine ,Dehydration ,Beta (finance) ,Exercise ,medicine.diagnostic_test ,Chemistry ,Public Health, Environmental and Occupational Health ,Brain ,030229 sport sciences ,General Medicine ,medicine.disease ,Endocrinology ,Analysis of variance ,Alpha power ,030217 neurology & neurosurgery ,Body Temperature Regulation - Abstract
Whole-body thermal and hydration clamps were used to evaluate their independent and combined impact on the electrical activity of the brain. It was hypothesised that those stresses would independently modify the electroencephalographic (EEG) responses, with those changes being greater when both stresses were superimposed. Alpha and beta spectral data (eyes closed) were collected from the frontal, central-parietal and occipital cortices of both hemispheres in resting, healthy and habitually active males (N = 8; mean age 25 years). Three dehydration states were investigated (euhydrated and 3% and 5% mass decrements) in each of two thermal states (normothermia [mean body temperature 36.3 °C] and moderate hyperthermia [38.4 °C]). The combination of those passively induced states yielded six levels of physiological strain, with the EEG data from each level separately examined using repeated-measures ANOVA with planned contrasts. When averaged across the frontal cortices, alpha power was elevated relative to the occipital cortices during moderate hyperthermia (P = 0.049). Conversely, beta power was generally reduced during hyperthermia (P = 0.013). Neither the alpha nor beta power spectra responded to dehydration, nor did dehydration elevate the heat-induced responses (P > 0.05). Moderate hyperthermia, but neither mild nor moderate dehydration, appeared to independently alter brain electrical activity. Moreover, the combination of moderate hyperthermia with 5% dehydration did not further increase those changes. That outcome was interpreted to mean that, when those states were superimposed, the resulting neurophysiological changes could almost exclusively be attributed to the thermal impact per se, rather than to their combined influences.
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- 2020
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14. Hyperthermia and dehydration: their independent and combined influences on physiological function during rest and exercise
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Gregory E Peoples, David J. R. Hoyle, Benjamin J. Haberley, Anne M. J. van den Heuvel, Nigel A.S. Taylor, and Rodney J. Croft
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Adult ,Male ,Hyperthermia ,Hot Temperature ,Fever ,Physiology ,Rest ,Blood Pressure ,Sweating ,Urine ,Body Temperature ,Incremental exercise ,03 medical and health sciences ,0302 clinical medicine ,Physiology (medical) ,medicine ,Humans ,Orthopedics and Sports Medicine ,Dehydration ,Exercise ,Rest (music) ,Skin ,Physiological function ,Renal sodium reabsorption ,Vasomotor ,Chemistry ,Public Health, Environmental and Occupational Health ,030229 sport sciences ,General Medicine ,medicine.disease ,Anesthesia ,030217 neurology & neurosurgery ,Body Temperature Regulation - Abstract
This experiment was designed to quantify the independent and combined influences of hyperthermia and dehydration on effector control during rest and exercise. To achieve that, whole-body hydration of healthy adults (N = 8) was manipulated into each of three states (euhydrated, 3% and 5% dehydrated), and then clamped within each of two thermal states (normothermia [mean body temperature: 36.1 °C] and moderate hyperthermia [mean body temperature: 38.2 °C]). Those treatment combinations provided six levels of physiological strain, with resting physiological data collected at each level. The effects of isothermal, thermally unclamped and incremental exercise were then investigated in normothermic individuals during each level of hydration. At rest, dehydration alone reduced urine flows by 83% (3% dehydrated) and 93% (5% dehydrated), while the reduction accompanying euhydrated hyperthermia was 86%. The sensitivities of renal water conservation to 3% dehydration (−21% mOsm−1 kg H2O−1) and moderate hyperthermia (−40% °C−1) were independent and powerful. Evidence was found for different renal mechanisms governing water conservation between those treatments. Cutaneous vasomotor and central cardiac responses were unresponsive to dehydration, but highly sensitive to passive thermal stress. Dehydration did not impair either whole-body or regional sweating during rest or exercise, and not even during incremental cycling to volitional exhaustion. In all instances, the physiological impact of these thermal- and hydration-state stresses was independently expressed, with no evidence of interactive influences. Renal water-conservation was independently and powerfully modified, exposing possible between-treatment differences in sodium reabsorption.
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- 2020
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15. ICNIRP Note: Critical Evaluation of Two Radiofrequency Electromagnetic Field Animal Carcinogenicity Studies Published in 2018
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Sharon A. Miller, Rodney J. Croft, Eric van Rongen, Martin Röösli, Guglielmo d'Inzeo, Tsutomu Okuno, Zenon Sienkiewicz, Gunde Ziegelberger, Carmela Marino, Akimasa Hirata, Soichi Watanabe, Gunnhild Oftedal, Adèle C. Green, Maria Feychting, Ziegelberger, G., Croft, R., Feychting, M., Green, A. C., Hirata, A., D'Inzeo, G., Marino, C., Miller, S., Oftedal, G., Okuno, T., van Rongen, E., Roosli, M., Sienkiewicz, Z., and Watanabe, S.
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Male ,Electromagnetic field ,medicine.medical_specialty ,radiationprotection ,Neoplasms, Radiation-Induced ,Time Factors ,Carcinogenesis ,Epidemiology ,Health, Toxicology and Mutagenesis ,International Commission on Non-Ionizing Radiation Protection (ICNIRP) ,Exposure ,Mice ,Electromagnetic Fields ,Animals ,Medicine ,Radiology, Nuclear Medicine and imaging ,Medical physics ,Carcinogen ,carcinogenesis ,exposure ,radiofrequency ,Radiation protection ,business.industry ,Rats ,Radiofrequency ,Female ,business - Abstract
Final results are now available from two large animal studies that investigated whether long-term exposure to radiofrequency (RF) electromagnetic fields (EMFs) associated with mobile (or cell) phones or base stations is carcinogenic; these studies hale from the US National Toxicology Program (NTP) and the Ramazzini Institute in Italy, respectively. In both cases, the authors concluded that they had demonstrated that RF EMFs are carcinogenic in male rats but not in female rats or mice (NTP only). The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has evaluated their methods and findings for potential information about the carcinogenicity of exposure to RF EMFs. We found that these studies had important strengths; for example, both followed good laboratory practice (GLP), both used much larger numbers of animals than previous research, and both exposed animals over the whole of their lives. We also noted some major weaknesses, including a lack of blinding, difficulties interpreting statistical analyses due to the association between longer lifespans and tumor occurrence in the exposed rats (NTP only), and failure to account for chance. ICNIRP concluded that these substantial limitations preclude conclusions being drawn concerning RF EMFs and carcinogenesis.
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- 2020
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16. Intended Human Exposure to Non-ionizing Radiation for Cosmetic Purposes
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Carmela Marino, Adèle C. Green, Sam R. Miller, Rianne Stam, Guglielmo d'Inzeo, Tsutomu Okuno, Zenon Sienkiewicz, Martin Röösli, T. Toivo, E. van Rongen, Rodney J. Croft, Gunde Ziegelberger, Soichi Watanabe, J. Abramowicz, Ken Karipidis, Gunnhild Oftedal, Akimasa Hirata, Maria Feychting, Ziegelberger, G., Karipidis, K., Abramowicz, J., D'Inzeo, G., Green, A. C., Miller, S., Okuno, T., Stam, R., Toivo, T., Croft, R., Feychting, M., Hirata, A., Marino, C., Oftedal, G., van Rongen, E., Roosli, M., Sienkiewicz, Z., and Watanabe, S.
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Radiation, Nonionizing ,medicine.medical_specialty ,Radiation ,Epidemiology ,business.industry ,Non-ionizing ,Health, Toxicology and Mutagenesis ,Cosmetics ,International Commission on Non-Ionizing Radiation Protection (ICNIRP) ,Radiation Exposure ,Radiation Dosage ,Non-ionizing radiation ,Radiation exposure ,Safety standards ,Radiation Protection ,Human exposure ,Medicine ,Radiology, Nuclear Medicine and imaging ,Medical physics ,Radiation protection ,Radiation Injuries ,business ,Health effects ,Skin - Abstract
Cosmetic devices using non-ionizing radiation (NIR) are increasingly available for people who wish to modify their appearance for aesthetic purposes. There are a wide range of NIR modalities used for cosmetic procedures, including devices that use optical radiation (laser, intense pulsed light, and light-emitting diode), electromagnetic fields, and ultrasound. Common procedures involving the application of NIR include epilation, skin rejuvenation, body sculpting and contouring, treatment of vascular and skin lesions, tattoo removal, and scar reduction. The majority of research on the use of NIR cosmetic devices has focused on the efficacy of the treatment rather than adverse effects or complications. Studies that assessed safety consisted mostly of case reports and small case series. Common adverse effects on the skin reported include mild and transient pain, erythema, swelling, and changes in pigmentation. Less common, more severe side effects include burns, blisters, scarring, persisting erythema, altered pigmentation, and eye damage. Some of the latter may have resulted from treatment errors. Particular groups of people that may be at greater risk from optical radiation include people with dark skin, with high sun exposure, and taking photosensitizing medications or supplements. There is lack of evidence for the safety profile of cosmetic NIR procedures during pregnancy. Reports of injuries to workers administering treatments with cosmetic NIR devices are rare, but inadvertent damage to the eye from optical devices may occur. Randomized controlled trials are required to fully assess potential adverse effects from the use of NIR cosmetic devices. Regulation varies worldwide and some regions apply the same safety classification and guidance as for medical devices. In order to reduce harm associated with the use of cosmetic devices, ICNIRP considers it important that regulations that cover all types and frequencies of cosmetic NIR devices are adopted worldwide and that there is greater oversight regarding their use.
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- 2020
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17. EEG Electrode Caps Can Reduce SAR Induced in the Head by GSM900 Mobile Phones.
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Denise L. Hamblin, Vitas Anderson, Robert L. McIntosh, Ray J. McKenzie, Andrew W. Wood, Steve Iskra, and Rodney J. Croft
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- 2007
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18. Is the P300 wave an endophenotype for schizophrenia? A meta-analysis and a family study.
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Elvira Bramon, Colm McDonald, Rodney J. Croft, Sabine Landau, Francesca Filbey, John H. Gruzelier, Pak C. Sham, Sophia Frangou, and Robin M. Murray
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- 2005
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19. Frequency‐dependent and montage‐based differences in phosphene perception thresholds via transcranial alternating current stimulation
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Ian D Evans, Sarah P. Loughran, Rodney J. Croft, Alexandre Legros, Stephen Palmisano, University of Western Ontario (UWO), Lawson Health Research Institute [London (ON) Canada], Euromov (EuroMov), and Université de Montpellier (UM)
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Adult ,Male ,medicine.medical_specialty ,Visual perception ,genetic structures ,Physiology ,media_common.quotation_subject ,Phosphenes ,Biophysics ,Stimulation ,02 engineering and technology ,Audiology ,Transcranial Direct Current Stimulation ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Perception ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Set (psychology) ,Electrodes ,Bioelectromagnetics ,ComputingMilieux_MISCELLANEOUS ,media_common ,Transcranial alternating current stimulation ,[SCCO.NEUR]Cognitive science/Neuroscience ,020206 networking & telecommunications ,General Medicine ,[SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics ,medicine.anatomical_structure ,Phosphene ,Sensory Thresholds ,Scalp ,Female ,Psychology ,Photic Stimulation - Abstract
It is well known that applying transcranial alternating current stimulation (tACS) to the scalp can generate artefactual visual perceptions of flashing or shimmering light known as phosphenes. The thresholds for generating these phosphenes have been used by international standards bodies to provide conservative estimates of the field strength required to interfere with human neural functioning and set safety limits accordingly. However, the precise relationship between electric currents and phosphene perception thresholds remains uncertain. The present study used tACS to systematically investigate the effects of the location and the frequency of stimulation on phosphene perception thresholds. These thresholds were obtained from 24 participants using a within-subject design as a function of scalp stimulation sites (FPz-Cz versus Oz-Cz) and stimulation frequency (2-30 Hz in steps of 2 Hz). Phosphene perception thresholds were consistently lower for FPz-Cz stimulation, and regardless of tACS location were lowest for 16 Hz stimulation. Threshold variation between participants was very small, which is meaningful when setting standards based on phosphenes. Bioelectromagnetics. 2019;40:365-374. © 2019 Bioelectromagnetics Society.
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- 2019
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20. Translocation of silica nanospheres through giant unilamellar vesicles (GUVs) induced by a high frequency electromagnetic field
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Palalle G. Tharushi Perera, Rodney J. Croft, Nevena Todorova, Zoltan Vilagosh, Elena P. Ivanova, Russell J. Crawford, Irene Yarovsky, Kateryna Bazaka, and Olha Bazaka
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chemistry.chemical_classification ,Materials science ,Membrane permeability ,General Chemical Engineering ,Vesicle ,Biomolecule ,technology, industry, and agriculture ,Phospholipid ,General Chemistry ,chemistry.chemical_compound ,Molecular dynamics ,Membrane ,chemistry ,Electric field ,Biophysics ,lipids (amino acids, peptides, and proteins) ,POPC - Abstract
Membrane model systems capable of mimicking live cell membranes were used for the first time in studying the effects arising from electromagnetic fields (EMFs) of 18 GHz where membrane permeability was observed following exposure. A present lack of understanding of the mechanisms that drive such a rapid change in membrane permeabilization as well as any structural or dynamic changes imparted on biomolecules affected by high-frequency electromagnetic irradiation limits the use of 18 GHz EMFs in biomedical applications. A phospholipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) labelled with a fluorescent marker 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(lissamine rhodamine B sulfonyl) (rhodamine-DOPE) was used in constructing the giant unilamellar vesicles (GUVs). After three cycles of exposure, enhanced membrane permeability was observed by the internalisation of hydrophilic silica nanospheres of 23.5 nm and their clusters. All-atom molecular dynamics simulations of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membranes exposed to high frequency electric fields of different field strengths showed that within the simulation timeframe only extremely high strength fields were able to cause an increase in the interfacial water dynamics characterized by water dipole realignments. However, a lower strength, high frequency EMF induced changes of the water hydrogen bond network, which may contribute to the mechanisms that facilitate membrane permeabilization in a longer timeframe.
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- 2021
21. The Effect of GSM Electromagnetic Field Exposure on the Waking Electroencephalogram: Methodological Influences
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Sarah P. Loughran, Rodney J. Croft, Adam Verrender, and Anna Dalecki
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Adult ,medicine.medical_specialty ,medicine.diagnostic_test ,Physiology ,business.industry ,Radio Waves ,Rest ,Biophysics ,Alpha (ethology) ,Reproducibility of Results ,Electroencephalography ,General Medicine ,Audiology ,Electromagnetic Fields ,Signal-to-noise ratio (imaging) ,medicine ,Ceiling effect ,Humans ,Radiology, Nuclear Medicine and imaging ,business ,Eyes open ,Alpha power ,Resting eeg ,Eeg alpha - Abstract
Although there is consistent evidence that exposure to radiofrequency electromagnetic fields (RF-EMF) increases the spontaneous resting alpha spectral power of the electroencephalogram (EEG), the reliability of this evidence is uncertain as some studies have also failed to observe this effect. The present study aimed to determine whether the effect of RF-EMF exposure on EEG alpha power depends on whether EEG is derived from eyes open or closed conditions and assessed earlier (5-min) versus later (25-min) in the exposure interval. Thirty-six adults participated in three experimental sessions, each involving one exposure: "Sham," "Low," and "High" RF-EMF corresponding to peak spatial specific absorption rates averaged over 10 g of 0, 1, and 2 W/kg, respectively. Resting EEG was recorded at baseline (no exposure), during, and after exposure. Alpha power increase was found to be greater for the eyes open than eyes closed EEG during both the High (P = 0.04) and Low (P = 0.04) RF-EMF exposures. There was also a trend toward it being larger at the end, versus the start of the "High" 30-min exposure (P 0.01; eyes open condition). This suggests that the use of eyes closed conditions, and insufficient RF-EMF exposure durations, are likely explanations for the failure of some studies to detect an RF-EMF exposure-related increase in alpha power, as such methodological choices decrease signal-to-noise ratios and increase type II error.
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- 2021
22. Effects of Acceleration-Induced Reductions in Retinal and Cerebral Oxygenation on Human Performance
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Rodney J. Croft, Nigel A.S. Taylor, Ola Eiken, Arne Tribukait, and Roger Kölegård
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Adult ,Male ,medicine.medical_specialty ,Visual perception ,Acceleration ,Prefrontal Cortex ,Audiology ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Cerebral oxygenation ,Task Performance and Analysis ,medicine ,Humans ,Prefrontal cortex ,Sweden ,Spectroscopy, Near-Infrared ,Working memory ,business.industry ,Retinal Vessels ,Retinal ,Cognition ,030229 sport sciences ,General Medicine ,Healthy Volunteers ,Time changes ,Oxygen ,Memory, Short-Term ,chemistry ,Blood oxygenation ,Aerospace Medicine ,Visual Perception ,Female ,business ,030217 neurology & neurosurgery - Abstract
BACKGROUND: Ischemic hypoxia induced by suprathreshold G-force loading can adversely affect vision, cognition, and lead to loss of consciousness (LOC). The purpose of this study was to determine whether reductions in cerebral oxygenation, caused by subthreshold G-forces (up to 4 Gz and of limited durations that do not lead to LOC), would affect visual perception and working memory performance.METHODS: Sixteen subjects performed visual perception and working memory tasks both before and during Gz exposures (1, 2.2, 3, 4 with leg pressurization, 4 with leg and abdomen pressurization) within a human-use centrifuge.RESULTS: As measured using near-infrared spectroscopy, blood oxygenation over medial prefrontal cortex was similar in the 1 and 2.2 Gz conditions, but was reduced to a similar extent in the 3 and 4 Gz conditions. In parallel, visual perception accuracy was reduced in the 3 and 4 Gz conditions, with no difference between the 3 and 4 Gz conditions. No change in reaction time was seen. Conversely, neither accuracy nor reaction time changes were observed for the visual working memory task.DISCUSSION: These results indicate that although visual working memory is not affected, the ability to visually discriminate between stimuli is reduced at G-forces as low as 3 and 4 Gz. This may have important ramifications for pilots who are routinely subjected to such forces.Croft RJ, Klegrd R, Tribukait A, Taylor NAS, Eiken O. Effects of acceleration-induced reductions in retinal and cerebral oxygenation on human performance. Aerosp Med Hum Perform. 2021; 92(2):7582.
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- 2021
23. Acute effects of Δ
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Lisa-Marie, Greenwood, Samantha J, Broyd, Hendrika H, van Hell, Juanita, Todd, Alison, Jones, Robin M, Murray, Rodney J, Croft, Patricia T, Michie, and Nadia, Solowij
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Cannabinoids ,Hallucinogens ,Cannabidiol ,Humans ,Dronabinol ,Cannabis - Abstract
Mismatch negativity (MMN) is a candidate endophenotype for schizophrenia subserved by N-methyl-D-aspartate receptor (NMDAR) function and there is increasing evidence that prolonged cannabis use adversely affects MMN generation. Few human studies have investigated the acute effects of cannabinoids on brain-based biomarkers of NMDAR function and synaptic plasticity.The current study investigated the acute effects of ΔIn a randomised, double-blind, crossover placebo-controlled study, 18 frequent and 18 less-frequent cannabis users underwent 5 randomised drug sessions administered via vaporiser: (1) placebo; (2) THC 8 mg; (3) CBD 400 mg; (4) THC 8 mg + CBD 4 mg [THC + CBDRelative to placebo, both THC and CBD were observed to increase duration and intensity MMN amplitude in less-frequent users, and THC also increased frequency MMN in this group. The addition of low-dose CBD added to THC attenuated the effect of THC on duration and intensity MMN amplitude in less-frequent users. The same pattern of effects was observed following high-dose CBD added to THC on duration and frequency MMN in frequent users.The pattern of effects following CBD combined with THC on MMN may be subserved by different underlying neurobiological interactions within the endocannabinoid system that vary as a function of prior cannabis exposure. These results highlight the complex interplay between the acute effects of exogenous cannabinoids and NMDAR function. Further research is needed to determine how this process normalises after the acute effects dissipate and following repeated acute exposure.
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- 2020
24. Radiofrequency electromagnetic field exposure and risk perception: A pilot experimental study
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Michael J. Abramson, Christopher Brzozek, Berihun M. Zeleke, Rodney J. Croft, Peter M. Wiedemann, Geza Benke, Chhavi Raj Bhatt, and Frederik Freudenstein
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Adult ,Male ,animal structures ,Radio Waves ,media_common.quotation_subject ,Pilot Projects ,010501 environmental sciences ,01 natural sciences ,Biochemistry ,03 medical and health sciences ,Electromagnetic Fields ,0302 clinical medicine ,Perception ,Environmental health ,Background exposure ,Humans ,Medicine ,030212 general & internal medicine ,Health risk ,Exposure measurement ,0105 earth and related environmental sciences ,General Environmental Science ,media_common ,business.industry ,Australia ,Environmental Exposure ,Risk perception ,Female ,business ,Cell Phone - Abstract
Background Exposure to far-field radiofrequency electromagnetic fields (RF-EMF) has raised public concerns in recent decades. However, it is not known if individuals’ perception towards the health risks of RF-EMF is dependent on their knowledge of the objectively measured personal RF-EMF exposure levels. Objectives This pilot study aimed to demonstrate the feasibility of objectively measuring personal RF-EMF exposure from mobile phone base stations (MPBS) and to determine if the risk perception of people to the potential health risk of exposure to RF-EMF from MPBS is dependent on their knowledge of personal RF-EMF exposure levels. Design An experimental study was conducted in 383 adults, recruited in Melbourne, Australia. Participants were randomized to one of the three groups: 1) basic information group who were provided with basic information about RF-EMF to read prior to completing a risk perception assessment questionnaire; 2) precautionary group who were provided with an information pack which included precautionary messages; and 3) personal exposure measurement group who were provided with a summary of their quantitative RF-EMF exposure from MPBS. The same basic information about RF-EMF was also given to the precautionary and personal exposure measurement groups. Results Participants had a mean (± SD) age of 36.9 ± 12.5 years; 66.7% were women. Overall, 44.1% had noticed an MPBS in their neighbourhood. The mean (SD) values (from 1 to 7) for risk perceptions to RF-EMF from MPBS were 4.02 (1.67) for basic information, 3.82 (1.62) for precautionary messages, and 3.97 (1.72) for the personal exposure measurement groups. These differences were not statistically significant. Nevertheless, the personal exposure measurement group were more confident that they could protect themselves from RF-EMF than the precautionary or basic information groups. Conclusion Our findings suggest that providing people with personal RF-EMF exposure measurements may not affect their perceived risk from MPBS, but increase their confidence in protecting themselves.
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- 2019
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25. A randomised controlled trial of vaporised Δ9-tetrahydrocannabinol and cannabidiol alone and in combination in frequent and infrequent cannabis users: acute intoxication effects
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Robin M. Murray, Jennifer H. Martin, Rodney J. Croft, Kuna Rueb, Juanita Todd, Nadia Solowij, Hendrika H van Hell, Samantha J. Broyd, Alison L Jones, Dave Martelozzo, Patricia T. Michie, Zheng Liu, Peter Galettis, and Lisa-Marie Greenwood
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Drug ,medicine.medical_specialty ,media_common.quotation_subject ,medicine.medical_treatment ,Placebo-controlled study ,Placebo ,digestive system ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,Randomized controlled trial ,law ,Internal medicine ,mental disorders ,medicine ,Pharmacology (medical) ,Adverse effect ,Biological Psychiatry ,media_common ,biology ,business.industry ,organic chemicals ,General Medicine ,biology.organism_classification ,digestive system diseases ,030227 psychiatry ,3. Good health ,Psychiatry and Mental health ,surgical procedures, operative ,Cannabis ,Cannabinoid ,business ,Cannabidiol ,030217 neurology & neurosurgery ,medicine.drug - Abstract
Access to cannabis and cannabinoid products is increasing worldwide for recreational and medicinal use. Two primary compounds within cannabis plant matter, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), are both psychoactive, but only THC is considered intoxicating. There is significant interest in potential therapeutic properties of these cannabinoids and of CBD in particular. Some research has suggested that CBD may ameliorate adverse effects of THC, but this may be dose dependent as other evidence suggests possible potentiating effects of THC by low doses of CBD. We conducted a randomised placebo controlled trial to examine the acute effects of these compounds alone and in combination when administered by vaporisation to frequent and infrequent cannabis users. Participants (n = 36; 31 male) completed 5 drug conditions spaced one week apart, with the following planned contrasts: placebo vs CBD alone (400 mg); THC alone (8 mg) vs THC combined with low (4 mg) or high (400 mg) doses of CBD. Objective (blind observer ratings) and subjective (self-rated) measures of intoxication were the primary outcomes, with additional indices of intoxication examined. CBD showed some intoxicating properties relative to placebo. Low doses of CBD when combined with THC enhanced, while high doses of CBD reduced the intoxicating effects of THC. The enhancement of intoxication by low-dose CBD was particularly prominent in infrequent cannabis users and was consistent across objective and subjective measures. Most effects were significant at p
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- 2019
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26. Framing effects in risk communication messages - Hazard identification vs. risk assessment
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Adam Verrender, C Bohmert, Sarah P. Loughran, Frederik Freudenstein, Rodney J. Croft, and Peter M. Wiedemann
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Radio Waves ,media_common.quotation_subject ,Applied psychology ,010501 environmental sciences ,Hazard analysis ,01 natural sciences ,Biochemistry ,Risk Assessment ,03 medical and health sciences ,0302 clinical medicine ,Electromagnetic Fields ,Perception ,Risk communication ,Humans ,030212 general & internal medicine ,0105 earth and related environmental sciences ,General Environmental Science ,media_common ,Communication ,Framing effect ,Environmental agent ,Risk perception ,Framing (social sciences) ,Risk assessment ,Psychology - Abstract
The way in which risk communication messages are framed can influence recipients' risk perceptions. Despite this, there is a limited understanding of how framing is responsible for influencing risk perception. One particularly important element may be whether a risk communication message is framed as a completed 'risk assessment' (specifying a magnitude of risk to the public as a function of the exposure level), or as a 'hazard identification' (a statement regarding whether an environmental agent could in principle cause detrimental health effects in humans, without addressing whether such effects may occur in practice). The current study aimed to investigate for the first time whether framing a risk communication message regarding 'mobile phones and health' as a hazard identification or as a risk assessment affects the reader's risk perception. Using an online survey, participants were separated into three groups and shown either an original press release from the International Agency for Research on Cancer regarding mobile phones and cancer (Group 1), or the press release with additional text modules intended to frame the press release as either a risk assessment (Group 2) or a hazard identification (Group 3). The experimental manipulation was successful in that framing the message as a hazard identification reduced the number of people that believed the press release was a risk assessment, whereas framing it as a risk assessment was not able to increase the number of people who thought that it was a risk assessment. However, no differences in risk perception were found between the groups. In an attempt to ascertain the reason for this lack of framing effect on the radiofrequency electromagnetic fields risk perception measures, it was found that pre-existing interpretations of risk and hazard strongly predicted risk perception, regardless of experimental group. Participants who believed that the International Agency for Research on Cancer conducted a hazard identification perceived lower risks and were less convinced that radiofrequency electromagnetic field exposure from mobile phones increases cancer risks. The results of the study demonstrate the importance of understanding the distinction between a hazard identification and a risk assessment, and suggest that radiofrequency electromagnetic field risk communication needs to develop means for empowering the public to differentiate between hazards and risks.
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- 2020
27. Can explicit suggestions about the harmfulness of EMF exposure exacerbate a nocebo response in healthy controls?
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Adam Verrender, Frederik Freudenstein, Sarah P. Loughran, Anna Dalecki, and Rodney J. Croft
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Health Knowledge, Attitudes, Practice ,medicine.medical_specialty ,animal structures ,Nocebo ,Radio Waves ,Provocation test ,Video Recording ,Audiology ,Biochemistry ,Electromagnetic hypersensitivity ,03 medical and health sciences ,Electromagnetic Fields ,0302 clinical medicine ,Double-Blind Method ,medicine ,Humans ,030212 general & internal medicine ,Nocebo Effect ,Suggestion ,Adverse effect ,General Environmental Science ,business.industry ,medicine.disease ,Idiopathic environmental intolerance ,Anxiety ,Multiple Chemical Sensitivity ,medicine.symptom ,business ,030217 neurology & neurosurgery ,Multiple chemical sensitivity - Abstract
While there has been consistent evidence that symptoms reported by individuals who suffer from Idiopathic Environmental Intolerance attributed to Electromagnetic Fields (IEI-EMF) are not caused by EMF and are more closely associated with a nocebo effect, whether this response is specific to IEI-EMF sufferers and what triggers it, remains unclear. The present experiment tested whether perceived EMF exposure could elicit symptoms in healthy participants, and whether viewing an 'alarmist' video could exacerbate a nocebo response. Participants were randomly assigned to watch either an alarmist (N = 22) or control video (N = 22) before completing a series of sham and active radiofrequency (RF) EMF exposure provocation trials (2 open-label, followed by 12 randomized, double-blind, counterbalanced trials). Pre- and post-video state anxiety and risk perception, as well as belief of exposure and symptom ratings during the open-label and double-blind provocation trials, were assessed. Symptoms were higher in the open-label RF-ON than RF-OFF trial (p < .001). No difference in either symptoms (p = .183) or belief of exposure (p = .144) was observed in the double-blind trials. Participants who viewed the alarmist video had a significant increase in symptoms (p = .041), state anxiety (p < .01) and risk perception (p < .001) relative to the control group. These results reveal the crucial role of awareness and belief in the presentation of symptoms during perceived exposure to EMF, showing that healthy participants exhibit a nocebo response, and that alarmist media reports emphasizing adverse effects of EMF also contribute to a nocebo response.
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- 2018
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28. Comparison of radiofrequency electromagnetic field exposure levels in different everyday microenvironments in an international context
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Rodney J. Croft, Tony Kuo, Mohamed Aqiel Dalvie, Lisa Arangua, Martin Röösli, Sanjay Sagar, Seid M. Adem, Sarah P. Loughran, Michael E. Brunjes, Michael Jerrett, Joel M. Moskowitz, and Benjamin Struchen
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Automobile Driving ,Radio Waves ,Context (language use) ,Walking ,010501 environmental sciences ,Urban area ,01 natural sciences ,South Africa ,03 medical and health sciences ,Electromagnetic Fields ,0302 clinical medicine ,Nepal ,Humans ,030212 general & internal medicine ,Exposure measurement ,lcsh:Environmental sciences ,0105 earth and related environmental sciences ,General Environmental Science ,Exposure assessment ,lcsh:GE1-350 ,geography ,geography.geographical_feature_category ,business.industry ,Australia ,Environmental Exposure ,Residential area ,Mobile phone ,Public transport ,Environmental science ,Physical geography ,Rural area ,business ,Switzerland ,Environmental Monitoring - Abstract
Background: The aim of this study was to quantify RF-EMF exposure applying a tested protocol of RF-EMF exposure measurements using portable devices with a high sampling rate in different microenvironments of Switzerland, Ethiopia, Nepal, South Africa, Australia and the United States of America. Method: We used portable measurement devices for assessing RF-EMF exposure in 94 outdoor microenvironments and 18 public transport vehicles. The measurements were taken either by walking with a backpack with the devices at the height of the head and a distance of 20–30 cm from the body, or driving a car with the devices mounted on its roof, which was 170–180 cm above the ground. The measurements were taken for about 30 min while walking and about 15–20 min while driving in each microenvironment, with a sampling rate of once every 4 s (ExpoM-RF) and 5 s (EME Spy 201). Results: Mean total RF-EMF exposure in various outdoor microenvironments varied between 0.23 V/m (non-central residential area in Switzerland) and 1.85 V/m (university area in Australia), and across modes of public transport between 0.32 V/m (bus in rural area in Switzerland) and 0.86 V/m (Auto rickshaw in urban area in Nepal). For most outdoor areas the major exposure contribution was from mobile phone base stations. Otherwise broadcasting was dominant. Uplink from mobile phone handsets was generally very small, except in Swiss trains and some Swiss buses. Conclusions: This study demonstrates high RF-EMF variability between the 94 selected microenvironments from all over the world. Exposure levels tended to increase with increasing urbanity. In most microenvironments downlink from mobile phone base stations is the most relevant contributor. Keywords: Radio-frequency electromagnetic fields (RF-EMF), Microenvironment, Uplink, Downlink, Exposure assessment, Mobile phone handset, Mobile phone base station
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- 2018
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29. Does acute radio-frequency electromagnetic field exposure affect visual event-related potentials in healthy adults?
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Catriona A. Burdon, Nigel A.S. Taylor, Adam Verrender, Rodney J. Croft, Anna Dalecki, and Sarah P. Loughran
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Adult ,Male ,medicine.medical_specialty ,Adolescent ,Sensory system ,Audiology ,Affect (psychology) ,030218 nuclear medicine & medical imaging ,Young Adult ,03 medical and health sciences ,Cognition ,Discrimination, Psychological ,Electromagnetic Fields ,0302 clinical medicine ,Double-Blind Method ,Event-related potential ,Physiology (medical) ,Humans ,Medicine ,Latency (engineering) ,Cross-Over Studies ,business.industry ,Specific absorption rate ,Middle Aged ,Sensory Systems ,Neurology ,Acute exposure ,Visual Perception ,Evoked Potentials, Visual ,Female ,Neurology (clinical) ,Radio frequency ,business ,030217 neurology & neurosurgery - Abstract
Objective To use improved methods to address the question of whether acute exposure to radio-frequency (RF) electromagnetic fields (RF-EMF) affects early (80–200 ms) sensory and later (180–600 ms) cognitive processes as indexed by event-related potentials (ERPs). Methods Thirty-six healthy subjects completed a visual discrimination task during concurrent exposure to a Global System for Mobile Communications (GSM)-like, 920 MHz signal with peak-spatial specific absorption rate for 10 g of tissue of 0 W/kg of body mass (Sham), 1 W/kg (Low RF) and 2 W/kg (High RF). A fully randomised, counterbalanced, double-blind design was used. Results P1 amplitude was reduced (p = .02) and anterior N1 latency was increased (p = .04) during Exposure compared to Sham. There were no effects on any other ERP latencies or amplitudes. Conclusions RF-EMF exposure may affect early perceptual (P1) and preparatory motor (anterior N1) processes. However, only two ERP indices, out of 56 comparisons, were observed to differ between RF-EMF exposure and Sham, suggesting that these observations may be due to chance. Significance These observations are consistent with previous findings that RF-EMF exposure has no reliable impact on cognition (e.g., accuracy and response speed).
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- 2018
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30. Therapeutic Effects of Prolonged Cannabidiol Treatment on Psychological Symptoms and Cognitive Function in Regular Cannabis Users: A Pragmatic Open-Label Clinical Trial
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Shanlin Fu, Peter Galettis, Chao Suo, Nagesh B Pai, Nadia Solowij, Camilla Beale, Murat Yücel, Julie-Anne Prick, Hendrika H van Hell, Jennifer H. Martin, Lisa-Marie Greenwood, Samantha J. Broyd, and Rodney J. Croft
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cannabis ,medicine.medical_specialty ,psychological symptoms ,memory ,03 medical and health sciences ,cannabidiol ,0302 clinical medicine ,mental disorders ,medicine ,Pharmacology (medical) ,Psychiatry ,Original Research ,Pharmacology ,biology ,business.industry ,Therapeutic effect ,Cognition ,Cannabis use ,biology.organism_classification ,030227 psychiatry ,3. Good health ,attention ,Clinical trial ,Complementary and alternative medicine ,Cannabis ,Open label ,business ,Cannabidiol ,030217 neurology & neurosurgery ,medicine.drug - Abstract
Introduction: Chronic cannabis use has been associated with impaired cognition and elevated psychological symptoms, particularly psychotic-like experiences. While Δ9-tetrahydrocannabinol (THC) is thought to be primarily responsible for these deleterious effects, cannabidiol (CBD) is purported to have antipsychotic properties and to ameliorate cognitive, symptomatic, and brain harms in cannabis users. However, this has never been tested in a prolonged administration trial in otherwise healthy cannabis users. Here, we report the first study of prolonged CBD administration to a community sample of regular cannabis users in a pragmatic trial investigating potential restorative effects of CBD on psychological symptoms and cognition. Materials and Methods: Twenty frequent cannabis users (16 male, median age 25 years) underwent a 10-week open-label trial of 200 mg of daily oral CBD treatment, while continuing to use cannabis as usual. The majority of participants were daily cannabis users who had used cannabis for several years (median 5.5 years of regular use). Participants underwent psychological and cognitive assessments at baseline (BL) and post-treatment (PT) and were monitored weekly throughout the trial. Results: CBD was well tolerated with no reported side effects; however, participants retrospectively reported reduced euphoria when smoking cannabis. No impairments to cognition were found, nor were there deleterious effects on psychological function. Importantly, participants reported significantly fewer depressive and psychotic-like symptoms at PT relative to BL, and exhibited improvements in attentional switching, verbal learning, and memory. Increased plasma CBD concentrations were associated with improvements in attentional control and beneficial changes in psychological symptoms. Greater benefits were observed in dependent than in nondependent cannabis users. Conclusions: Prolonged CBD treatment appears to have promising therapeutic effects for improving psychological symptoms and cognition in regular cannabis users. Our findings require replication given the lack of a placebo control in this pragmatic trial, but suggest that CBD may be a useful adjunct treatment for cannabis dependence.
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- 2018
31. Temperature Rise for Brief Radio-Frequency Exposure Below 6 GHz
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Akimasa Hirata, Rodney J. Croft, Kari Jokela, Sachiko Kodera, Soichi Watanabe, and Daisuke Funahashi
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Electromagnetic field ,standardization ,Materials science ,product safety engineering ,General Computer Science ,dosimetry ,Pulse (signal processing) ,General Engineering ,TEMPERATURE ELEVATION ,Specific absorption rate ,radiation safety ,030218 nuclear medicine & medical imaging ,Computational physics ,03 medical and health sciences ,0302 clinical medicine ,Adverse health effect ,030220 oncology & carcinogenesis ,Continuous wave ,General Materials Science ,Radio frequency ,lcsh:Electrical engineering. Electronics. Nuclear engineering ,Absorption (electromagnetic radiation) ,Biological effects of radiation ,lcsh:TK1-9971 - Abstract
In international guidelines for human protection from radio-frequency (RF) electromagnetic fields, the specific absorption rate (SAR) averaged over 6 min and 10 g of tissue is used as a physical quantity to prevent excess local temperature rise. The resultant SAR restriction has been set to avoid potential adverse health effects due to the temperature elevation resulting from RF energy absorption. In the public consultation version of the upcoming ICNIRP RF guidelines (July 10, 2018), a specific absorption (SA) limit was set to avoid heating from brief exposures (shorter than 6 min). However, to the best of our knowledge, no prior research has evaluated the temperature rise for single/multiple pulses with energy equivalent to the 6-min exposure SAR restriction for continuous waves. This paper computed the temperature rise for brief pulse exposures based on bioheat computations. We first confirmed that the peak temperature rise for a pulse with SA corresponding to occupational exposure exceeds the steady-state temperature rise for temporally uniform continuous wave exposure. We then proposed the SA limit from a regression curve that is dependent on the duration of brief exposure to RF pulse(s). The temperature rise in a multilayer cube and an anatomical human model were also computed for exposures to multiple pulses. The temperature rise from multiple pulses satisfying the formula was found to be below the relevant threshold level. The SA based on this regression curve can be used as a metric to prevent excess temperature rise for different brief exposure scenarios below 6 min.
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- 2018
32. IEI-EMF provocation case studies: A novel approach to testing sensitive individuals
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G. James Rubin, Lena Hillert, Gunnhild Oftedal, Vitas Anderson, Sarah P. Loughran, Rodney J. Croft, and Adam Verrender
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medicine.medical_specialty ,animal structures ,Physiology ,business.industry ,Provocation test ,Significant difference ,Biophysics ,General Medicine ,Audiology ,Idiopathic environmental intolerance ,Electromagnetic hypersensitivity ,030218 nuclear medicine & medical imaging ,Emf exposure ,03 medical and health sciences ,Incident power density ,0302 clinical medicine ,Etiology ,Medicine ,Radiology, Nuclear Medicine and imaging ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
The etiology of Idiopathic Environmental Intolerance attributed to Electromagnetic Fields (IEI-EMF) is controversial. While the majority of studies have indicated that there is no relationship between EMF exposure and symptoms reported by IEI-EMF sufferers, concerns about methodological issues have been raised. Addressing these concerns, the present experiment was designed as a series of individual case studies to determine whether there is a relationship between radiofrequency-electromagnetic field (RF-EMF) exposure and an IEI-EMF individual's self-reported symptoms. Three participants aged 44-64 were tested during a series of sham and active exposure trials (2 open-label trials; 12 randomized, double-blind, counterbalanced trials), where symptom severity and exposure detection were scored using 100 mm visual analogue scales. The RF-EMF exposure was a 902-928 MHz spread spectrum digitally modulated signal with an average radiated power output of 1 W (0.3 W/m2 incident power density at the participant). In the double-blind trials, no significant difference in symptom severity or exposure detection was found for any of the participants between the two conditions. Belief of exposure strongly predicted symptom severity score for all participants. Despite accounting for several possible limitations, the present experiment failed to show a relationship between RF-EMF exposure and an IEI-EMF individual's symptoms. Bioelectromagnetics. 39:132-143, 2018. © 2017 Wiley Periodicals, Inc.
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- 2017
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33. The effect of a high frequency electromagnetic field in the microwave range on red blood cells
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Vladimir A. Baulin, Vy T. H. Pham, Rodney J. Croft, Elena P. Ivanova, and Russell J. Crawford
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0301 basic medicine ,Erythrocytes ,Scanning electron microscope ,lcsh:Medicine ,Article ,Cell membrane ,03 medical and health sciences ,0302 clinical medicine ,Electromagnetic Fields ,Microscopy ,medicine ,Animals ,Cytoskeleton ,Microwaves ,lcsh:Science ,Multidisciplinary ,Chemistry ,Bilayer ,lcsh:R ,Cytosol ,030104 developmental biology ,Membrane ,medicine.anatomical_structure ,Transmission electron microscopy ,030220 oncology & carcinogenesis ,Biophysics ,Microscopy, Electron, Scanning ,lcsh:Q ,Rabbits - Abstract
The effect of red blood cells (RBC) exposed to an 18 GHz electromagnetic field (EMF) was studied. The results of this study demonstrated for the first time that exposure of RBCs to 18 GHz EMF has the capacity to induce nanospheres uptake in RBCs. The uptake of nanospheres (loading efficiency 96% and 46% for 23.5 and 46.3 nm nanospheres respectively), their presence and locality were confirmed using three independent techniques, namely scanning electron microscopy, confocal laser scanning microscopy and transmission electron microscopy. It appeared that 23.5 nm nanospheres were translocated through the membrane into the cytosol, while the 46.3 nm-nanospheres were mostly translocated through the phospholipid-cholesterol bilayer, with only some of these nanospheres passing the 2D cytoskeleton network. The nanospheres uptake increased by up to 12% with increasing temperature from 33 to 37 °C. The TEM analysis revealed that the nanospheres were engulfed by the cell membrane itself, and then translocated into the cytosol. It is believed that EMF-induced rotating water dipoles caused disturbance of the membrane, initiating its deformation and result in an enhanced degree of membrane trafficking via a quasi-exocytosis process.
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- 2017
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34. Gaps in knowledge relevant to the 'Guidelines for limiting exposure to time-varying electric and magnetic fields (1 Hz-100 kHz)'
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Tsutomu Okuno, Adèle C. Green, Ken Karipidis, Sharon A. Miller, Gunde Ziegelberger, Maria Feychting, Akimasa Hirata, Isabelle Lagroye, Mats-Olof Mattsson, Gunnhild Oftedal, Carmela Marino, Soichi Watanabe, Zenon Sienkiewicz, Rodney J. Croft, Eric van Rongen, Martin Röösli, Guglielmo d'Inzeo, and Andrew Wood
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Physics ,Epidemiology ,Health, Toxicology and Mutagenesis ,Nuclear engineering ,International Commission on Non Ionizing Radiation Protection ,Limiting ,Radiation ,Non-ionizing radiation ,safety standards ,Magnetic field ,health effects ,radiation non-ionizing ,Radiology, Nuclear Medicine and imaging - Abstract
Sources of low-frequency fields are widely found in modern society. All wires or devices carrying or using electricity generate extremely low frequency (ELF) electric fields (EFs) and magnetic fields (MFs), but they decline rapidly with distance to the source. High magnetic flux densities are usually found in the vicinity of power lines and close to equipment using strong electrical currents, but can also be found in buildings with unbalanced return currents, or indoor transformer stations. For decades, epidemiological as well as experimental studies have addressed possible health effects of exposure to ELF-MFs. The main goal of ICNIRP is to protect people and the environment from detrimental exposure to all forms of non-ionizing radiation (NIR). To this end, ICNIRP provides advice and guidance by developing and disseminating exposure guidelines based on the available scientific research. Research in the low-frequency range began more than 40 years ago, and there is now a large body of literature available on which ICNIRP set its protection guidelines. A review of the literature has been carried out to identify possible relevant knowledge gaps, and the aim of this statement is to describe data gaps in research that would, if addressed, assist ICNIRP in further developing guidelines and setting revised recommendations on limiting exposure to electric and magnetic fields. It is articulated in two parts: the main document, which reviews the science related to LF data gaps, and the annex, which explains the methodology used to identify the data gaps.
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- 2020
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35. Uncertainty Analysis of Mobile Phone Use and Its Effect on Cognitive Function: The Application of Monte Carlo Simulation in a Cohort of Australian Primary School Children
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Jordy Kaufman, Michael J. Abramson, Christina Dimitriadis, Rodney J. Croft, Anna Dalecki, Berihun M. Zeleke, Malcolm R Sim, Geza Benke, Christopher Brzozek, and Kurt K. Benke
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Health, Toxicology and Mutagenesis ,Monte Carlo method ,lcsh:Medicine ,010501 environmental sciences ,01 natural sciences ,Article ,Cohort Studies ,03 medical and health sciences ,0302 clinical medicine ,Cognition ,Statistics ,Linear regression ,Humans ,030212 general & internal medicine ,Child ,uncertainty analysis ,Uncertainty analysis ,mobile phones ,Monte Carlo simulation ,cognitive function ,0105 earth and related environmental sciences ,Observational error ,Schools ,lcsh:R ,Public Health, Environmental and Occupational Health ,Australia ,Uncertainty ,Records ,Cell Phone Use ,radiofrequency electromagnetic fields ,Mobile phone ,Go/no go ,Null hypothesis ,Monte Carlo Method ,Stroop effect - Abstract
Previous epidemiological studies on health effects of radiation exposure from mobile phones have produced inconsistent results. This may be due to experimental difficulties and various sources of uncertainty, such as statistical variability, measurement errors, and model uncertainty. An analytical technique known as the Monte Carlo simulation provides an additional approach to analysis by addressing uncertainty in model inputs using error probability distributions, rather than point-source data. The aim of this investigation was to demonstrate using Monte Carlo simulation of data from the ExPOSURE (Examination of Psychological Outcomes in Students using Radiofrequency dEvices) study to quantify uncertainty in the output of the model. Data were collected twice, approximately one year apart (between 2011 and 2013) for 412 primary school participants in Australia. Monte Carlo simulation was used to estimate output uncertainty in the model due to uncertainties in the call exposure data. Multiple linear regression models evaluated associations between mobile phone calls with cognitive function and found weak evidence of an association. Similar to previous longitudinal analysis, associations were found for the Go/No Go and Groton maze learning tasks, and a Stroop time ratio. However, with the introduction of uncertainty analysis, the results were closer to the null hypothesis.
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- 2019
36. Radiofrequency Electromagnetic Field Exposure and the Resting EEG: Exploring the Thermal Mechanism Hypothesis
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Anna Dalecki, Adam Verrender, Kyoko Tagami, Sarah P. Loughran, Catriona A. Burdon, Rodney J. Croft, Nigel A.S. Taylor, and Joonhee Park
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Adult ,medicine.medical_specialty ,Adolescent ,Radio Waves ,Rest ,Health, Toxicology and Mutagenesis ,Provocation test ,Alpha (ethology) ,lcsh:Medicine ,Blood Pressure ,Finger temperature ,010501 environmental sciences ,Audiology ,Electroencephalography ,01 natural sciences ,Article ,Young Adult ,03 medical and health sciences ,Electromagnetic Fields ,0302 clinical medicine ,Double-Blind Method ,exposure limits ,Humans ,Medicine ,Resting eeg ,mobile phones ,0105 earth and related environmental sciences ,medicine.diagnostic_test ,business.industry ,lcsh:R ,Public Health, Environmental and Occupational Health ,Skin temperature ,Middle Aged ,electroencephalogram ,Alpha band ,radiofrequency electromagnetic fields ,Eeg activity ,Female ,Skin Temperature ,business ,body temperature ,Cell Phone ,030217 neurology & neurosurgery - Abstract
There is now strong evidence that radiofrequency electromagnetic field (RF-EMF) exposure influences the human electroencephalogram (EEG). While effects on the alpha band of the resting EEG have been repeatedly shown, the mechanisms underlying that effect have not been established. The current study used well-controlled methods to assess the RF-EMF exposure effect on the EEG and determine whether that effect might be thermally mediated. Thirty-six healthy adults participated in a randomized, double-blind, counterbalanced provocation study. A water-perfusion suit (34 C) was worn throughout the study to negate environmental influences and stabilize skin temperature. Participants attended the laboratory on four occasions, the first being a calibration session and the three subsequent ones being exposure sessions. During each exposure session, EEG and skin temperature (8 sites) were recorded continuously during a baseline phase, and then during a 30 min exposure to a 920 MHz GSM-like signal (Sham, Low RF-EMF (1 W/kg) and High RF-EMF (2 W/kg)). Consistent with previous research, alpha EEG activity increased during the High exposure condition compared to the Sham condition. As a measure of thermoregulatory activation, finger temperature was found to be higher during both exposure conditions compared to the Sham condition, indicating for the first time that the effect on the EEG is accompanied by thermoregulatory changes and suggesting that the effect of RF-EMF on the EEG is consistent with a thermal mechanism.
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- 2019
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37. Effects of selective outcome reporting on risk perception
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Rodney J. Croft, Frederik Freudenstein, Berihun M. Zeleke, Peter M. Wiedemann, and Sarah P. Loughran
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media_common.quotation_subject ,010501 environmental sciences ,01 natural sciences ,Biochemistry ,03 medical and health sciences ,Electromagnetic Fields ,0302 clinical medicine ,Full results ,Outcome reporting ,Perception ,Humans ,Medicine ,Risk communication ,030212 general & internal medicine ,0105 earth and related environmental sciences ,General Environmental Science ,media_common ,Brain Neoplasms ,business.industry ,Glioma ,Risk perception ,Increased risk ,Mobile phone ,business ,Risk assessment ,Cell Phone ,Clinical psychology - Abstract
The current study aimed to investigate how selective reporting of study results indicating increased health effects will influence its receiver's risk perception. Using the example of the Interphone Study from 2010 on mobile phone usage and cancer, an online experiment was conducted separating respondents into two groups. One group of subjects was informed selectively about a relationship between heavy mobile phone use and an elevated risk of glioma (brain cancer) only. The other group of subjects was informed about the full results of the analyses of glioma risk by cumulative call time, which suggests that other than for the heavy users, there were no statistically significant elevated risks related to mobile phone use. The results showed that selective reporting of risk information increased risk perception when compared to receiving the full information. Additionally, the selectively informed subjects revealed a stronger tendency towards overgeneralization of the 'elevated brain cancer risk' to all mobile phone users, although this did not extend to an overgeneralization to other electromagnetic field sources or differences in the perception of a usage time dependency for possible health risks. These results indicate that reporting of full results is an important factor in effective risk communication.
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- 2021
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38. The independent influences of heat strain and dehydration upon cognition
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Rodney J. Croft, Benjamin J. Haberley, Anne M. J. van den Heuvel, Nigel A.S. Taylor, and David J. R. Hoyle
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Adult ,Male ,Hyperthermia ,medicine.medical_specialty ,Visual perception ,Physiology ,Audiology ,Heat Stress Disorders ,Body Temperature ,Random Allocation ,03 medical and health sciences ,Cognition ,0302 clinical medicine ,Physiology (medical) ,medicine ,Humans ,Orthopedics and Sports Medicine ,Dehydration ,Effects of sleep deprivation on cognitive performance ,Working memory ,business.industry ,Confounding ,Public Health, Environmental and Occupational Health ,030229 sport sciences ,General Medicine ,Response bias ,medicine.disease ,Memory, Short-Term ,Perception ,business ,030217 neurology & neurosurgery - Abstract
Many researchers have addressed the potential effects of hyperthermia and dehydration on cognition, often revealing contradictory outcomes. A possible reason for this inconsistency is that experiments may have been inadequately designed for such effects. In this study, the impact of hyperthermia, dehydration and their combination on cognition were evaluated in eight young males, after accounting for a range of experimental limitations. Passive heating and thermal clamping at two mean body temperatures (36.5, 38.5 °C) were performed under three hydration states (euhydrated, 3 and 5% dehydrated) to assess their effects on difficulty-matched working memory and visual perception tasks, and on a difficulty manipulated perceptual task. Data were analysed according to signal detection theory to isolate changes in response sensitivity, bias and speed. Neither moderate hyperthermia (P = 0.141) nor dehydration (P > 0.604) modified response sensitivity, nor did they significantly interact (P > 0.698). Therefore, the ability to distinguish correct from incorrect responses was unaffected. Nevertheless, hyperthermia, but not dehydration (P = 0.301), reduced the response bias (−0.08 versus 2.2 [normothermia]; P = 0.010) and reaction time (mean reduction 49 ms; P
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- 2017
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39. A Closer Look at the Thresholds of Thermal Damage
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Zenon Sienkiewicz, Bernard Veyret, Rodney J. Croft, Gunde Ziegelberger, and Eric van Rongen
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electromagnetic fields ,Internationality ,Epidemiology ,Threshold limit value ,Health, Toxicology and Mutagenesis ,Dose metrics ,Guidelines as Topic ,ICNIRP Statement ,Radiation Dosage ,World Health Organization ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Radiation Protection ,0302 clinical medicine ,Radiation Monitoring ,health effects ,Humans ,Radiology, Nuclear Medicine and imaging ,Threshold Limit Values ,Radiation Injuries ,Task group ,business.industry ,Burns, Electric ,International Commission on Non Ionizing Radiation Protection ,Dose-Response Relationship, Radiation ,Reliability engineering ,Critical parameter ,030220 oncology & carcinogenesis ,Environmental science ,Radiation monitoring ,Thermal damage ,Occupational exposure ,Radiation protection ,business - Abstract
The International Commission on Non-Ionizing Radiation Protection issued guidelines in 1998 for limiting public and occupational exposure to radiofrequency electromagnetic fields (100 kHz to 300 GHz). As part of the process of updating this advice, a 2‐d workshop titled “A closer look at the thresholds of thermal damage” was held from 26–28 May 2015 in Istanbul to re-examine the thermal basis of the guidelines and to provide further information on heat-related effects and thresholds of thermal damage. Overall, the workshop provided much useful information relevant to revision of the guidelines. Participants indicated that the effects of heating from radiofrequency fields are consistent with those from other sources, and that the information derived from those studies can be applied to radiofrequency-induced heating. Another conclusion was that absolute temperature of tissues was more important for thermal damage than temperature change. The discussion suggested that the 6‐min averaging time used in international guidelines was valid for whole-body exposures but with a large uncertainty: 30 min may be a more appropriate averaging time for localized exposures, and less than 1 min for implanted medical devices. The duration of whole-body radiofrequency exposure is a critical parameter that often determines the effect threshold, but this will be affected by other, ongoing thermoregulation, which is dependant on many factors. The thresholds for localized radiofrequency exposure were difficult to determine because of the potential range of exposure conditions and the possibility of radiofrequency-induced local hotspots. Suggestions for future dose metrics and further research were discussed and are included in this report.
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- 2016
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40. Evidence for a differential contribution of early perceptual and late cognitive processes during encoding to episodic memory impairment in schizophrenia
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Jayashri Kulkarni, Pradeep J. Nathan, Amity E. Green, Paul B. Fitzgerald, Patrick Johnston, and Rodney J. Croft
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Adult ,Male ,medicine.medical_specialty ,genetic structures ,Memory, Episodic ,Neuropsychological Tests ,Audiology ,behavioral disciplines and activities ,03 medical and health sciences ,Cognition ,0302 clinical medicine ,Retrospective memory ,Explicit memory ,medicine ,Humans ,Semantic memory ,Evoked Potentials ,Late positive component ,Episodic memory ,Biological Psychiatry ,Recognition memory ,Memory Disorders ,Long-term memory ,Autobiographical memory ,Australia ,Brain ,Electroencephalography ,Middle Aged ,030227 psychiatry ,Psychiatry and Mental health ,Case-Control Studies ,Schizophrenia ,Female ,Schizophrenic Psychology ,Psychology ,psychological phenomena and processes ,030217 neurology & neurosurgery ,Cognitive psychology - Abstract
Schizophrenia is characterised by significant episodic memory impairment that is thought to be related to problems with encoding, however the neuro-functional mechanisms underlying these deficits are not well understood. The present study used a subsequent recognition memory paradigm and event-related potentials (ERPs) to investigate temporal aspects of episodic memory encoding deficits in schizophrenia.Electroencephalographic data was recorded in 24 patients and 19 healthy controls whilst participants categorised single words as pleasant/unpleasant. ERPs were generated to subsequently recognised versus unrecognised words on the basis of a forced-choice recognition memory task. Subsequent memory effects were examined with the late positive component (LPP). Group differences in N1, P2, N400 and LPP were examined for words correctly recognised.Patients performed more poorly than controls on the recognition task. During encoding patients had significantly reduced N400 and LPP amplitudes than controls. LPP amplitude correlated with task performance however amplitudes did not differ between patients and controls as a function of subsequent memory. No significant differences in N1 or P2 amplitude or latency were observed.The present results indicate that early sensory processes are intact and dysfunctional higher order cognitive processes during encoding are contributing to episodic memory impairments in schizophrenia.
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- 2016
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41. Pulse modulated radiofrequency exposure influences cognitive performance
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Sarah P. Loughran, Rodney J. Croft, Adam Verrender, Raymond J. McKenzie, and Anna Dalecki
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Adult ,Male ,medicine.medical_specialty ,Adolescent ,Provocation test ,Audiology ,Radiation Dosage ,030218 nuclear medicine & medical imaging ,Task (project management) ,Young Adult ,03 medical and health sciences ,Cognition ,0302 clinical medicine ,Double-Blind Method ,Task Performance and Analysis ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Effects of sleep deprivation on cognitive performance ,Radiological and Ultrasound Technology ,Pulse (signal processing) ,Working memory ,business.industry ,Dose-Response Relationship, Radiation ,Middle Aged ,Memory, Short-Term ,Visual discrimination ,Female ,business ,030217 neurology & neurosurgery - Abstract
To investigate whether exposure to pulse modulated radiofrequency (PM RF) influences human cognitive performance, and whether it does so in a dose-dependent manner.Thirty-six healthy adults participated in a randomized, double-blind, counterbalanced provocation study. Cognitive performance was assessed using a visual discrimination task and a modified Sternberg working memory task, which were calibrated to individual performance levels in a preliminary testing session. An sXh920 planar exposure system was used to generate a 920 MHz GSM-like signal, providing three conditions (peak-spatial SAR averaged over 10 g) of 0 W/kg (sham), 1 W/kg (low RF) and 2 W/kg (high RF).A significant decrease in reaction time (RT) in the Sternberg working memory task was found during exposure compared to sham. This effect was not dose-dependent.Cognitive performance was shown to be faster under PM RF conditions, relative to sham, in a working memory task. While the majority of the literature has not found effects of PM RF exposure on cognitive performance, it is possible that the methodological improvements employed in the present study increased sensitivity, and thus the ability to detect potential effects.
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- 2016
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42. White matter correlates of episodic memory encoding and retrieval in schizophrenia
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Rodney J. Croft, Paul B. Fitzgerald, Jerome Joseph Maller, and Amity E. Green
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Adult ,Male ,Memory, Episodic ,Fornix, Brain ,Neuroscience (miscellaneous) ,Prefrontal Cortex ,Posterior parietal cortex ,Grey matter ,Temporal lobe ,White matter ,03 medical and health sciences ,0302 clinical medicine ,Parietal Lobe ,Fractional anisotropy ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Gray Matter ,Myelin Sheath ,Brain Mapping ,Memory Disorders ,Fornix ,Parietal lobe ,Brain ,Middle Aged ,White Matter ,Temporal Lobe ,030227 psychiatry ,Psychiatry and Mental health ,Diffusion Tensor Imaging ,medicine.anatomical_structure ,Psychotic Disorders ,Case-Control Studies ,Schizophrenia ,Anisotropy ,Female ,Schizophrenic Psychology ,Orbitofrontal cortex ,Psychology ,Neuroscience ,030217 neurology & neurosurgery - Abstract
Episodic memory (EM) impairments in schizophrenia (SZ) are predictive of functional outcome and are a potential endophenotype of the disorder. The current study investigated the neuroanatomical correlates of EM encoding and retrieval in SZ with structural magnetic resonance and diffusion tensor imaging (DTI) measures in 22 patients with SZ and 22 age- and gender-matched healthy controls. Tract-based Spatial Statistics (TBSS) was used to investigate microstructural alterations in white matter (WM), while FreeSurfer surface-based analysis was used to determine abnormalities in grey matter (GM) and WM volumetrics and cortical thickness. Compared to controls, patients demonstrated GM deficits in temporal and parietal regions and lower fractional anisotropy (FA) of WM in diffuse brain regions. Patients also demonstrated reduced functioning in both encoding and retention of auditory-verbal EM. Among patients but not controls, EM encoding correlated with WM volume in the orbitofrontal cortex and increased radial diffusivity in the fornix, whereas EM retrieval correlated with WM volume in posterior parietal cortex. These findings suggest a differential role for frontal and parietal WM in EM encoding and retrieval processes, while myelin integrity of the fornix may play a specific role in mediating EM encoding processes in SZ.
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- 2016
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43. Schizotypy and auditory mismatch negativity in a non-clinical sample of young adults
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Rhoshel K. Lenroot, Patricia T. Michie, Hendrika H van Hell, Lisa-Marie Greenwood, Rodney J. Croft, Juanita Todd, Samantha J. Broyd, Jason M. Bruggemann, and Nadia Solowij
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Adult ,Male ,medicine.medical_specialty ,Adolescent ,Schizotypy ,Population ,Neuroscience (miscellaneous) ,Mismatch negativity ,Electroencephalography ,Audiology ,Receptors, N-Methyl-D-Aspartate ,Synaptic Transmission ,behavioral disciplines and activities ,Developmental psychology ,Schizotypal Personality Disorder ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Event-related potential ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Association (psychology) ,education ,education.field_of_study ,medicine.diagnostic_test ,medicine.disease ,Schizotypal personality disorder ,030227 psychiatry ,Psychiatry and Mental health ,Acoustic Stimulation ,Psychotic Disorders ,Schizophrenia ,Evoked Potentials, Auditory ,Female ,Psychology ,psychological phenomena and processes ,030217 neurology & neurosurgery - Abstract
Schizophrenia may be conceptualised using a dimensional approach to examine trait-like expression such as schizotypy within non-clinical populations to better understand pathophysiology. A candidate psychosis-risk marker, the auditory mismatch negativity (MMN) is thought to index the functionality of glutamatergic NMDA receptor mediated neurotransmission. Although the MMN is robustly reduced in patients with schizophrenia, the association between MMN and schizotypy in the general population is under-investigated. Thirty-five healthy participants completed the Schizotypal Personality Questionnaire (SPQ) and a multi-feature MMN paradigm (standards 82%, 50ms, 1000Hz, 80dB) with duration (100ms), frequency (1200Hz) and intensity (90dB) deviants (6% each). Spearman's correlations were used to explore the association between schizotypal personality traits and MMN amplitude. Few associations were identified between schizotypal traits and MMN. Higher Suspiciousness subscale scores tended to be correlated with larger frequency MMN amplitude. A median-split comparison of the sample on Suspiciousness scores showed larger MMN (irrespective of deviant condition) in the High compared to the Low Suspiciousness group. The trend-level association between MMN and Suspiciousness is in contrast to the robustly attenuated MMN amplitude observed in schizophrenia. Reductions in MMN may reflect a schizophrenia-disease state, whereas non-clinical schizotypy may not be subserved by similar neuropathology.
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- 2016
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44. The Effects of Precautionary Messages about Electromagnetic Fields from Mobile Phones and Base Stations Revisited: The Role of Recipient Characteristics
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Rodney J. Croft, Christoph A Boehmert, Jonathon Pye, and Peter M. Wiedemann
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050103 clinical psychology ,media_common.quotation_subject ,05 social sciences ,Individual difference ,010501 environmental sciences ,01 natural sciences ,Developmental psychology ,Risk perception ,Mobile phone ,Physiology (medical) ,Reading (process) ,Perception ,medicine ,Anxiety ,Trait anxiety ,0501 psychology and cognitive sciences ,Multiple linear regression analysis ,medicine.symptom ,Safety, Risk, Reliability and Quality ,Psychology ,Social psychology ,0105 earth and related environmental sciences ,media_common - Abstract
Precautionary messages have been shown to increase recipients' threat perceptions about radio-frequency electromagnetic fields (RF-EMFs) emitted by mobile phones and mobile phone base stations. The current study explored the interplay of variables on the side of message recipients with this effect. The individual difference variables of interest were gender, trait anxiety, personal need for structure, and personal fear of invalidity. Furthermore, the study determined whether the increased threat perception is accompanied by emotional distress. A total of 298 university students answered a survey after reading either a basic text about RF-EMFs or a text including precautionary information. Linear multiple regression with interactions analyses showed that the effect of precautionary messages differed for people with different levels of trait anxiety. How trait anxiety was related to the effect of precautionary messages in turn depended on participants' gender. Personal need for structure and personal fear of invalidity were mostly unrelated to the effect of precautionary messages. Regarding participants' emotional distress, we found no difference in state anxiety scores between those participants who received precautionary information and those who did not. The findings show that the effects of precautionary messages on threat perception depend on individual difference variables such as recipients' trait anxiety and gender. Also, the fact that precautionary communication did not result in heightened state anxiety challenges the assumption that precautionary messages induce fear or anxiety.
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- 2016
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45. PC 12 Pheochromocytoma Cell Response to Super High Frequency Terahertz Radiation from Synchrotron Source
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Russell J. Crawford, Rodney J. Croft, Palalle G. Tharushi Perera, Jason V. Wandiyanto, Kateryna Bazaka, Denver P. Linklater, Dominique R. T. Appadoo, Vi Khanh Truong, Chaitali Dekiwadia, Olha Bazaka, Elena P. Ivanova, Samuel Cheeseman, Mark J. Tobin, and Jitraporn Vongsvivut
- Subjects
0301 basic medicine ,Cancer Research ,Materials science ,Terahertz radiation ,Scanning electron microscope ,Population ,02 engineering and technology ,Radiation ,lcsh:RC254-282 ,Article ,Cell membrane ,03 medical and health sciences ,medicine ,Irradiation ,education ,cell viability ,education.field_of_study ,Environmental exposure ,021001 nanoscience & nanotechnology ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,PC 12 neuronal cells ,terahertz exposure ,super high frequency electromagnetic radiation ,030104 developmental biology ,medicine.anatomical_structure ,Oncology ,Transmission electron microscopy ,Biophysics ,0210 nano-technology - Abstract
High frequency (HF) electromagnetic fields (EMFs) have been widely used in many wireless communication devices, yet within the terahertz (THz) range, their effects on biological systems are poorly understood. In this study, electromagnetic radiation in the range of 0.3&ndash, 19.5 ×, 1012 Hz, generated using a synchrotron light source, was used to investigate the response of PC 12 neuron-like pheochromocytoma cells to THz irradiation. The PC 12 cells remained viable and physiologically healthy, as confirmed by a panel of biological assays, however, exposure to THz radiation for 10 min at 25.2 ±, 0.4 °, C was sufficient to induce a temporary increase in their cell membrane permeability. High-resolution transmission electron microscopy (TEM) confirmed cell membrane permeabilization via visualisation of the translocation of silica nanospheres (d = 23.5 ±, 0.2 nm) and their clusters (d = 63 nm) into the PC 12 cells. Analysis of scanning electron microscopy (SEM) micrographs revealed the formation of atypically large (up to 1 µ, m) blebs on the surface of PC 12 cells when exposed to THz radiation. Long-term analysis showed no substantial differences in metabolic activity between the PC 12 cells exposed to THz radiation and untreated cells, however, a higher population of the THz-treated PC 12 cells responded to the nerve growth factor (NGF) by extending longer neurites (up to 0&ndash, 20 µ, m) compared to the untreated PC12 cells (up to 20 µ, m). These findings present implications for the development of nanoparticle-mediated drug delivery and gene therapy strategies since THz irradiation can promote nanoparticle uptake by cells without causing apoptosis, necrosis or physiological damage, as well as provide a deeper fundamental insight into the biological effects of environmental exposure of cells to electromagnetic radiation of super high frequencies.
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- 2019
46. Exposure to high-frequency electromagnetic field triggers rapid uptake of large nanosphere clusters by pheochromocytoma cells
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Palalle G Tharushi Perera, The Hong Phong Nguyen, Chaitali Dekiwadia, Jason Wandiyanto, Igor Sbarski, Olga Bazaka, Kateryna Bazaka, Russell J Crawford, Rodney J Croft, and Elena P Ivanova
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0301 basic medicine ,electromagnetic fields ,animal structures ,Cell Membrane Permeability ,Membrane permeability ,microwave ,Biophysics ,Adrenal Gland Neoplasms ,Pharmaceutical Science ,Bioengineering ,Pheochromocytoma ,PC12 Cells ,Biomaterials ,18 GHz ,03 medical and health sciences ,chemistry.chemical_compound ,International Journal of Nanomedicine ,Lactate dehydrogenase ,Drug Discovery ,Dielectric heating ,medicine ,Animals ,Original Research ,chemistry.chemical_classification ,Biomolecule ,Organic Chemistry ,Specific absorption rate ,Biological activity ,Biological Transport ,General Medicine ,Membrane transport ,medicine.disease ,EMFs ,Silicon Dioxide ,PC 12 neuronal cells ,Rats ,030104 developmental biology ,chemistry ,membrane permeability ,Nanospheres - Abstract
Palalle G Tharushi Perera,1 The Hong Phong Nguyen,2 Chaitali Dekiwadia,3 Jason V Wandiyanto,1 Igor Sbarski,1 Olga Bazaka,4 Kateryna Bazaka,5 Russell J Crawford,4 Rodney J Croft,6 Elena P Ivanova4 1Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC, Australia; 2Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam; 3RMIT Microscopy and Microanalysis Facility, College of Science, Engineering and Health, RMIT University, Melbourne, VIC, Australia; 4School of Science, RMIT University, Melbourne, VIC, Australia; 5School of Chemistry, Physics, Mechanical Engineering, Queensland University of Technology, Brisbane, QLD, Australia; 6School of Psychology, Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia Background: Effects of man-made electromagnetic fields (EMF) on living organisms potentially include transient and permanent changes in cell behaviour, physiology and morphology. At present, these EMF-induced effects are poorly defined, yet their understanding may provide important insights into consequences of uncontrolled (e.g., environmental) as well as intentional (e.g., therapeutic or diagnostic) exposure of biota to EMFs. In this work, for the first time, we study mechanisms by which a high frequency (18 GHz) EMF radiation affects the physiology of membrane transport in pheochromocytoma PC 12, a convenient model system for neurotoxicological and membrane transport studies. Methods and results: Suspensions of the PC 12 cells were subjected to three consecutive cycles of 30s EMF treatment with a specific absorption rate (SAR) of 1.17 kW kg-1, with cells cooled between exposures to reduce bulk dielectric heating. The EMF exposure resulted in a transient increase in membrane permeability for 9 min in up to 90 % of the treated cells, as demonstrated by rapid internalisation of silica nanospheres (diameter d ≈ 23.5 nm) and their clusters (d ≈ 63 nm). In contrast, the PC 12 cells that received an equivalent bulk heat treatment behaved similar to the untreated controls, showing lack to minimal nanosphere uptake of approximately 1–2 %. Morphology and growth of the EMF treated cells were not altered, indicating that the PC 12 cells were able to remain viable after the EMF exposure. The metabolic activity of EMF treated PC 12 cells was similar to that of the heat treated and control samples, with no difference in the total protein concentration and lactate dehydrogenase (LDH) release between these groups. Conclusion: These results provide new insights into the mechanisms of EMF-induced biological activity in mammalian cells, suggesting a possible use of EMFs to facilitate efficient transport of biomolecules, dyes and tracers, and genetic material across cell membrane in drug delivery and gene therapy, where permanent permeabilisation or cell death is undesirable. Keywords: electromagnetic fields, EMFs, 18 GHz, PC 12 neuronal cells, membrane permeability, microwave
- Published
- 2018
47. Mobile phone use and incidence of brain tumour histological types, grading or anatomical location: a population-based ecological study
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Mark Elwood, Rodney J. Croft, Lydiawati Tjong, Ken Karipidis, Geza Benke, and Masoumeh Sanagou
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Oncology ,Adult ,Male ,medicine.medical_specialty ,incidence trends ,Population ,Temporal lobe ,03 medical and health sciences ,symbols.namesake ,0302 clinical medicine ,Risk Factors ,Glioma ,Internal medicine ,glioma ,medicine ,Humans ,030212 general & internal medicine ,Poisson regression ,Registries ,education ,brain cancer ,education.field_of_study ,mobile phone ,business.industry ,Brain Neoplasms ,Incidence (epidemiology) ,Incidence ,Research ,Australia ,glioblastoma ,Ecological study ,Brain ,Correction ,General Medicine ,Middle Aged ,medicine.disease ,Cell Phone Use ,Mobile phone ,030220 oncology & carcinogenesis ,Relative risk ,symbols ,Female ,Public Health ,Neoplasm Grading ,business - Abstract
ObjectiveSome studies have reported increasing trends in certain brain tumours and a possible link with mobile phone use has been suggested. We examined the incidence time trends of brain tumour in Australia for three distinct time periods to ascertain the influence of improved diagnostic technologies and increase in mobile phone use on the incidence of brain tumours.DesignIn a population-based ecological study, we examined trends of brain tumour over the periods 1982–1992, 1993–2002 and 2003–2013. We further compared the observed incidence during the period of substantial mobile phone use (2003–2013) with predicted (modelled) incidence for the same period by applying various relative risks, latency periods and mobile phone use scenarios.SettingNational Australian incidence registration data on primary cancers of the brain diagnosed between 1982 and 2013.Population16 825 eligible brain cancer cases aged 20–59 from all of Australia (10 083 males and 6742 females).Main outcome measuresAnnual percentage change (APC) in brain tumour incidence based on Poisson regression analysis.ResultsThe overall brain tumour rates remained stable during all three periods. There was an increase in glioblastoma during 1993–2002 (APC 2.3, 95% CI 0.8 to 3.7) which was likely due to advances in the use of MRI during that period. There were no increases in any brain tumour types, including glioma (−0.6, –1.4 to 0.2) and glioblastoma (0.8, –0.4 to 2.0), during the period of substantial mobile phone use from 2003 to 2013. During that period, there was also no increase in glioma of the temporal lobe (0.5, –1.3 to 2.3), which is the location most exposed when using a mobile phone. Predicted incidence rates were higher than the observed rates for latency periods up to 15 years.ConclusionsIn Australia, there has been no increase in any brain tumour histological type or glioma location that can be attributed to mobile phones.
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- 2018
48. Are there hidden dangers to mobile phone use?
- Author
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Giuseppe Curcio, Rodney J. Croft, and Sarah P. Loughran
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medicine.diagnostic_test ,Mechanism (biology) ,Mobile phone ,Computer science ,Perspective (graphical) ,medicine ,Cognition ,Sleep (system call) ,Electroencephalography ,Sleep architecture ,Sleep duration ,Cognitive psychology - Abstract
This chapter tries to ascertain whether mobile phones (and mobile phone-like exposures) impact on health, with the premise being that, if they do, then this would not only illuminate a hidden danger, but also necessitate a search for a new biophysical mechanism. Electromagnetic energy travels as waves, which, depending on the particular frequency, can interact with the body in different ways. Health effects from the low-level exposures from mobile phones are not predicted because the resultant heating is too low. The body engages in a tightly regulated cycle of physiological changes that induce and promote effective sleep. These can be measured in terms of indices of sleep architecture, such as sleep duration, and the underlying electroencephalograph (EEG) changes that accompany these stages. The EEG power spectrum can be resolved into relatively discrete frequency bands, which represent the sum of a range of distinct cognitive processes.
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- 2018
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49. RF EMF Risk Perception Revisited: Is the Focus on Concern Sufficient for Risk Perception Studies?
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Frederik Freudenstein, Joe Wiart, Peter M. Wiedemann, Rodney J. Croft, Christoph Böhmert, Radio-Fréquences Microondes et Ondes Millimétriques (RFM2), Laboratoire Traitement et Communication de l'Information (LTCI), Institut Mines-Télécom [Paris] (IMT)-Télécom Paris-Institut Mines-Télécom [Paris] (IMT)-Télécom Paris, Département Communications & Electronique (COMELEC), and Télécom ParisTech
- Subjects
Value (ethics) ,Male ,thematic relevance ,Health Knowledge, Attitudes, Practice ,Radio Waves ,Health, Toxicology and Mutagenesis ,0211 other engineering and technologies ,lcsh:Medicine ,02 engineering and technology ,Survey methodology ,[SPI]Engineering Sciences [physics] ,Risk Factors ,Surveys and Questionnaires ,RF EMF ,questionnaire design ,survey methodology ,Everyday life ,exposure perception ,media_common ,Radiation Exposure ,Focus (linguistics) ,Europe ,[STAT]Statistics [stat] ,Female ,risk perception ,risk communication ,base stations ,mobile phones ,0305 other medical science ,Psychology ,Social psychology ,Adult ,media_common.quotation_subject ,Article ,03 medical and health sciences ,Electromagnetic Fields ,Perception ,Humans ,Relevance (information retrieval) ,Literature & rhetoric ,021110 strategic, defence & security studies ,030505 public health ,lcsh:R ,Public Health, Environmental and Occupational Health ,Risk perception ,Assumption of risk ,Cell Phone ,ddc:800 - Abstract
An implicit assumption of risk perception studies is that concerns expressed in questionnaires reflect concerns in everyday life. The aim of the present study is to check this assumption, i.e., the extrapolability of risk perceptions expressed in a survey, to risk perceptions in everyday life. To that end, risk perceptions were measured by a multidimensional approach. In addition to the traditional focus on measuring the magnitude of risk perceptions, the thematic relevance (how often people think about a risk issue) and the discursive relevance (how often people think about or discuss a risk issue) of risk perceptions were also collected. Taking into account this extended view of risk perception, an online survey was conducted in six European countries with 2454 respondents, referring to radio frequency electromagnetic field (RF EMF) risk potentials from base stations, and access points, such as WiFi routers and cell phones. The findings reveal that the present study’s multidimensional approach to measuring risk perception provides a more differentiated understanding of RF EMF risk perception. High levels of concerns expressed in questionnaires do not automatically imply that these concerns are thematically relevant in everyday life. We use thematic relevance to distinguish between enduringly concerned (high concern according to both questionnaire and thematic relevance) and not enduringly concerned participants (high concern according to questionnaire but no thematic relevance). Furthermore, we provide data for the empirical value of this distinction: Compared to other participants, enduringly concerned subjects consider radio frequency electromagnetic field exposure to a greater extent as a moral and affective issue. They also see themselves as highly exposed to radio frequency electromagnetic fields. However, despite these differences, subjects with high levels of thematic relevance are nevertheless sensitive to exposure reduction as a means for improving the acceptance of base stations in their neighborhood. This underlines the value of exposure reduction for the acceptance of radio frequency electromagnetic field communication technologies.
- Published
- 2017
- Full Text
- View/download PDF
50. Effects of aging and depression on mnemonic discrimination ability
- Author
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R Fontana, Rodney J. Croft, David A. Camfield, Jessica Mills, and Keith Wesnes
- Subjects
Adult ,Male ,medicine.medical_specialty ,Aging ,Pattern separation ,Adolescent ,Experimental and Cognitive Psychology ,Mnemonic ,050105 experimental psychology ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Discrimination, Psychological ,Negatively associated ,medicine ,Humans ,0501 psychology and cognitive sciences ,Psychiatry ,Depression (differential diagnoses) ,Depressive symptoms ,Recognition memory ,Aged ,Aged, 80 and over ,Depressive Disorder, Major ,05 social sciences ,Cognition ,Recognition, Psychology ,Middle Aged ,humanities ,Psychiatry and Mental health ,Neuropsychology and Physiological Psychology ,Female ,Geriatrics and Gerontology ,Young group ,Dysthymic Disorder ,Psychology ,030217 neurology & neurosurgery ,Clinical psychology - Abstract
Ageing and depression have been found to be associated with poorer performance in mnemonic discrimination. In the current study, a two-response format mnemonic similarity test, Cognitive Drug Research MST, was used to compare these effects. Seventy-six participants were tested; with 52 participants in the young group, aged 18–35 years, and 24 participants in the elderly group, aged 55 years or older. Twenty-two young participants and 10 elderly participants met DSM-IV criteria for MDD or dysthymia. Age-related deficits were found for lure identification and speed of response. Differences in speed of responses to lure images were found for younger depressed participants, and depressive symptom severity was found to be negatively associated with lure identification accuracy in the elderly. These findings may be viewed as putative behavioral correlates of decreased pattern separation ability, which may be indicative of altered hippocampal neurogenesis in aging and depression.
- Published
- 2017
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