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The issue of radiation exposure as a potential cause of cerebrovascular disease raises many concerns. The aim of the present study was to investigate the epidemiology of stroke and transient ischemic attacks (TIA) along with the associated risk factors among the population of East Kazakhstan exposed to ionising radiation from the former Semipalatinsk Nuclear Test Site (SNTS) in comparison with the unexposed population of the same region. This 5-year retrospective cross-sectional study included the data on 10,970 patients, of whom the majority (62.3%) suffered from ischemic stroke, 11.7% had hemorrhagic stroke and the remaining 26.0% had TIA. At the moment when stroke/TIA happened, exposed patients were younger than the unexposed (mean age 63 years versus 64 years, p

We estimate the potential remaining COVID-19 hospitalisation and death burdens in 19 European countries by estimating the proportion of each country’s population that has acquired immunity to severe disease through infection or vaccination. Our results suggest many European countries could still face high burdens of hospitalisations and deaths, particularly those with lower vaccination coverage, less historical transmission and/or older populations. Continued non-pharmaceutical interventions and efforts to achieve high vaccination coverage are required in these countries to limit severe COVID-19 outcomes.

Micronuclei represent whole chromosome or large acentric fragments lagging behind the ana-telophasic separation of cell division. However, it progresses towards completion of karyokinesis and eventually gets included in one of the two daughter cells through cytokinesis. The frequency of micronuclei was estimated in 107 subjects exposed to methyl isocyanate (MIC) gas 30-years post-disaster and compared with 35 unexposed subjects of similar socio-cultural background from the same geographical region. Ethical approval and participants’ informed consent were obtained, and quality issues were validated prior to the proposed investigation. Peripheral blood was collected for each participant from their residence and transported to Mumbai for technical processing and cytogenetic analysis. Replicate cultures with 0.5 ml of whole blood were stimulated in 5 ml of serum supplemented RPMI1640 medium and maintained at 37°C for 72 h. The cells were dropped onto chilled slides following standard harvesting schedule, air dried and stained in Giemsa. Microscopic observation of 1000 cells for each subject has recognized lymphocyte cells (MNC) with micronucleus (MN). The ratio of MN and MNC indicated number of micronuclei per micronucleated cell. Statistical analysis revealed exposure related incidences of MN, MNC and MN/MNC, which was significant (p

A study was carried out to evaluate the health effects and risk assessment due to arsenic toxicity on an unexposed population residing in an arsenic-exposed zone. The studied population includes mothers (aged 23–31 years old) and their children (7 months–4 years old) from ten different families of an arsenic-exposed village, Madhusudankati of Gaighata block, North 24 Parganas district. The presence of arsenic in drinking water ranged from 3 to 7.95 µg/l, which was lower than the World Health Organization-recommended value, i.e., 10 µg/l. Cooked rice, consumed on a daily basis through the diet, contributed a considerable amount of arsenic, ranging from 11.6 to 97.6 µg/kg. Infants’ daily diets include breast milk, cow’s milk, and commercial baby food (Cerelac); homemade food mixtures contributed 6.34, 17.4 µg/l and 75.1, 207 µg/kg of arsenic, respectively. The daily dietary intakes of arsenic through water and cooked rice for mothers (0.88 µg/kg bw/day) and infants (0.63 µg/kg bw/day) were within the permissible limit (3 µg/kg bw/day). Mean urine arsenic concentration of the mothers and infants was 3.10 and 3 µg/l respectively, which showed that the populations were exposed to arsenic-free drinking water. Arsenic deposition in scalp hair and nails for the mothers was 3321 and 5829 µg/kg, respectively, which was higher than in the infants (1655 and 4148 µg/kg), signifying that the populations studied were sub-clinically exposed to arsenic toxicity. The potential cancer risk of arsenic for infants is lower through consumption of breast milk (2.11*10–6) compared to other dietary intakes (3.11*10–5). Future cancer risk assessment through ingestion of water and cooked rice for the mothers (1.79*10–4 and 4.04*10–4) was higher than for the infants (2.63*10–5and 2.11*10–5) compared to the US Environmental Protection Agency-recommended value for cancer risk (1*10–6).

Objective: The aim of this study is to determine the effects of drinking water with high fluoride level on liver functions. Method: This is a descriptive comparative cross-sectional study conducted at Sammu rind village where the drinking water has increase fluoride content. The comparative area was Gadap town where the drinking water has normal fluoride level. Sampling was done randomly and sample size was calculated by WHO calculator and found to be 121 each for exposed and unexposed population. Blood samples taken for liver functions included bilirubin, AST, ALT, Alkaline phosphate, Gamma GT, total protein, albumin and globulin. SPSS version 16 was used for analysis. Mean and SD calculated for quantitative variable and the two comparative groups were cross-tabulated. To check the statistical significance t-test was applied. Results: There was no statistically significant difference with consideration to serum bilirubin, ALT, and AST. However, statistically significant difference was established with respect to alkaline phosphatase, Gamma GT total proteins and A/G ratio between two groups. Conclusion: In our study, there was no evidence of impaired liver function tests in subjects drinking water with high fluoride content.

Background: Mercury is a common environmental contaminant and it is also harmful to human health. Among reported toxicities, its harmful effect on hypertension is poorly documented. In Kazakhstan, Temirtau city has been reported to have a high level of mercury contamination from an acetaldehyde production factory. Therefore, we aimed to investigate the association between serum profile of cytokines and the development of hypertension among the exposed citizens. Methods: We selected 81 individuals for study, out of them, 41 exposed ones suffered hypertension and 40 – unexposed healthy controls in villages Chkalovo, Samarkand, Gagarinskoye, Tegiszhol, Rostovka in 2016. Mercury content in urine was studied by inversion voltammetry. Cytokine levels of IL-2, IL-6, IL-10 and TNF-α were determined by ELISA. Results: Mercury-exposed citizens, especially those with hypertension, had significantly higher concentrations of inflammatory cytokines TNF-α, IL-2, IL-6 and anti-inflammatory cytokine IL-10 as compared to the unexposed population. The dependence of the mercury level in urine on IL-2 content was also detected. Therefore, chronic low doses of exposure to mercury were associated with an increase in serum levels of immune markers and with the increased risk of hypertension. Conclusion: The presence of mercury in the body probably affected the expression of interleukin-2, one of the main cytokines that coordinate immune response.

ObjectivesThe increase in production of multiwalled carbon nanotubes (MWCNTs) has led to growing concerns about health risks. In this study, we assessed the association between occupational exposure to MWCNTs and cardiovascular biomarkers.MethodsA cross-sectional study was performed among 22 workers of a company commercially producing MWCNTs (subdivided into lab personnel with low or high exposure and operators), and a gender and age-matched unexposed population (n=42). Exposure to MWCNTs and 12 cardiovascular markers were measured in participants’ blood (phase I). In a subpopulation of 13 exposed workers and six unexposed workers, these measures were repeated after 5 months (phase II). We analysed associations between MWCNT exposure and biomarkers of cardiovascular risk, adjusted for age, body mass index, sex and smoking.ResultsWe observed an upward trend in the concentration of endothelial damage marker intercellular adhesion molecule-1 (ICAM-1), with increasing exposure to MWCNTs in both phases. The operator category showed significantly elevated ICAM-1 geometric mean ratios (GMRs) compared with the controls (phase I: GMR=1.40, P=1.30E-3; phase II: GMR=1.37, P=0.03). The trends were significant both across worker categories (phase I: P=1.50E-3; phase II: P=0.01) and across measured GM MWCNT concentrations (phase I: P=3.00E-3; phase II: P=0.01). No consistent significant associations were found for the other cardiovascular markers.ConclusionThe associations between MWCNT exposure and ICAM-1 indicate endothelial activation and an increased inflammatory state in workers with MWCNT exposure.

Following the 1984 Bhopal methyl isocyanate (MIC) gas disaster, genetic alterations were sporadically reported on small cohorts. However, the outcome of the multi-center cytogenetic screening conducted at that time remains unknown and no follow-up studies on the long-term effects of MIC exposure have been published. The present work examines genetic changes in the exposed population,with the aim of identifying any long-term effects of MIC. G-Banded metaphases were studied in lymphocytes of 130 individuals. Chromosomal aberrations (CA) were broadly grouped as abnormal cells (Abc), aberrations (Abn), and aberration/abnormal cell (Abn/Abc). From the previous multi-center screening, 946 records were retrieved, from which CA, sister chromatid exchanges (SCE), and cell-cycle kinetics (RI) were computed. In our analysis of the previous study, Abc and Abn were higher in the moderately and severely exposed groups than in the unexposed population. Abc appeared uniform in all groups of the present study, although Abn and Abn/Abc were higher in the exposed groups. Aberrations were now significantly higher in the unexposed and moderately exposed groups than in the previous screening. Although Abn and Abc now appeared lower in severely exposed subjects, the Abn/Abc ratio was higher, perhaps due to more rearrangements and damage in a smaller number of Abc. This result may be attributed to differences between the methods used in the studies, then and now. Elevated SCEs and reduced RI were seen in the severely exposed population shortly after exposure, and stable/clonal rearrangements were seen 30 y later. Follow-up of index cases and their progenies is needed.

In the 1980s, villages in the Kurdistan region of Iraq were exposed to chemical weapons (CWs), which killed and injured thousands of civilians. There has been no clinical assessment of the long-term effects of CWs exposure on those injured. We report the first such evaluation of CW effects on long-term health of children. Patients from the CW-exposed areas were interviewed to assess previous and current clinical history and underwent clinical examination. The status of organs known to be targets of CWs, including skin, eyes, respiratory and neuromuscular systems, was assessed. Children of similar age and social background, but with no history of CW exposure, were selected as a control population. Results showed that 70% of children in the CWs group had chronic health problems in contrast to 3.3% in the unexposed group ( p < 0.0001). Fifty-five per cent of the CW-exposed group had long-term visual impairment but none in the unexposed population. Thirty-six per cent of the CW-exposed group had chronic dermatological conditions compared with 0.8% of the unexposed group ( p < 0.0001), 31% of the CWs group had neurological sequelae compared with 0.4% of the unexposed group ( p < 0.0001) and 51% of the CWs group had long-term respiratory problems compared with 1.5% of the unexposed group ( p < 0.0001). Respiratory complaints including asthma, chronic bronchitis and bronchiectasis were particularly common. Our study suggests that CWs used were probably a combination of sulphur mustard and organophosphate nerve agents. Results also indicate that the prevalence of acute and chronic health problems following exposure to CW agents appear to be higher in children compared with reported data in adults.

Estimating the population attributable fraction (PAF) of melanomas due to sun exposure is challenging as there are no unexposed population nor reliable exposure data. In high incidence countries, a historic cohort of the South Thames cancer registry was used as a minimally exposed population using the formula PAF = (observed incidence-incidence in minimally exposure)/observed incidence. In this study, we apply this method, constructing a minimally exposed cohort for Colombia and also using the historical South Thames data, using melanoma incidence data from the population-based cancer registry of Cali, Colombia for the period 1967-2012. The historic cohort incidence rates were very similar to those of Thames, but cohort effects were smaller for women and nonexistent for men. Age-specific incidence rates of these minimally exposed cohorts were applied to recent population numbers. For females, PAFs were 19% using the historic Thames cohort and 25% using the historic Cali cohort, corresponding numbers for males were 62% (vs. Thames) and 0% (vs. Cali). Taking into account the incidence rates of acral melanomas, which are not sun related, the PAF increased in women to 26% (vs. Thames) and 34% (vs. Cali) and for men 77% (vs. Thames). This exercise shows the modest contribution of exposure to ultraviolet radiation in the burden of melanoma in low-incidence countries, as well as the importance to take into consideration the acral lentiginous melanomas.

Introduction Eastern and North-Eastern regions of Kazakhstan are considered to be environmentally disadvantaged due to industrial pollution and activity of the former Semipalatinsk Nuclear Test Site. Ferrous metallurgy is represented by the world’s largest ferroalloy plant located in Aksu. In addition to a ferroalloy plant, Aksu is the home for the largest thermal power plant in Kazakhstan. Objective Biomonitoring of 31 hair and blood trace elements (Ag, Ba, Be, Bi, Cs, Co, Ce, Cr, Cu, Eu, Gd, Hf, In, La, Li, Mn, Mo, Nb, Nd, Pb, Sc, Sn, Tl, Th, U, V, W, Y, Yb, Zn, and Zr) in non-occupationally exposed population residing in polluted areas of East Kazakhstan and Pavlodar regions. Methods Five case groups, residing in the vicinity to the former Semipalatinsk Nuclear Test Site (Akzhar, Borodulikha, and Karaul) or in proximity to industrial plants (Aksu and Ust-Kamenogorsk) have been assessed vs. controls from a rural settlement in Kurchum. In total, 204 hair and blood samples were analyzed by inductively coupled plasma mass spectrometry. Results The observed blood concentrations of trace elements were in agreement with earlier studies on residents of industrially polluted areas. Elevated levels of blood Ba, Mn, Pb, V, and Zn were detected in residents of Aksu and Ust-Kamenogorsk. The elemental composition of head hair was characterized by greater stability between the study sites. Conclusion Residency near the former Semipalatinsk Test Site could be considered as safe, while the environmental status of industrial settlements appears to be rather adverse.

Background: Occupational crystalline silica dust exposure is associated with an elevated risk of pulmonary tuberculosis (PTB). However, there is less evidence for an association with environmental silica dust exposure. Methods: A cross-sectional study of 310 participants was conducted in an exposed community living within 2 km of gold mine tailings and an unexposed population residing more than 10 km from the nearest gold mine tailing. Chest radiographs (n = 178) were read for PTB, past or current, by three readers. Results: Past or current PTB was radiologically identified in 14.4% (95%CI 9.2&ndash, 21.8) in the exposed and 7.5% (95%CI 2.8&ndash, 18.7) in the unexposed groups. Multivariate logistic regression models suggested that PTB prevalence was independently associated with exposure to second-hand smoke (OR = 8.13, 95%CI 1.16&ndash, 57.22), a lower body mass index (OR = 0.88, 95%CI 0.80&ndash, 0.98), previous diagnosis and treatment of PTB (OR = 8.98, 95%CI 1.98&ndash, 40.34), and exposure to dust in the workplace from sand, construction, and/or mining industries (OR = 10.2, 95%CI 2.10&ndash, 50.11). Conclusion: We found no association between PTB and environmental exposure to gold mine tailing dust. However, workplace silica dust exposure is a significant risk factor for PTB in South Africa, and PTB patients of working age should be screened for silica exposure.

Purpose: Vertebral hemangiomas (VHs) are the most common benign tumors of the spine that may cause bone resorption. Megavoltage irradiation is usually the treatment of choice for the management of symptomatic VHs. The current study was conducted to estimate the risk for carcinogenesis from radiotherapy of this benign disease on the basis of the calculated radiation doses to healthy organs. Methods: The Monte Carlo N-particle transport code was employed to simulate the irradiation with 6 MV x-rays of a VH presented in the cervical, upper thoracic, lower thoracic, and lumbar spine. The average radiation dose (Dav) received by each critical organ located outside the primarily irradiated area was calculated. Three-dimensional treatment plans were also generated for the VHs occurring at the four different sites of the spinal cord based on patients’ computed tomography data. The organ equivalent dose (OED) to each radiosensitive structure, which was partly encompassed by the applied treatment fields, was calculated with the aid of differential dose–volume histograms. The Dav and the OED values were combined with a linear-no-threshold model and a nonlinear mechanistic model, respectively, to estimate the organ-, age-, and gender-specific lifetime attributable risks (LARs) for cancer development. The estimated risks were compared with the respective nominal lifetime intrinsic risks (LIRs) for the unexposed population. Results: For a standard target dose of 34 Gy, the OED varied from 0.39–5.15 Gy by the organ of interest and the irradiation site. The Dav range for the out-of-field organs was 4.9 × 10−4 to 0.56 Gy. The LAR for the appearance of malignancies in the partially in-field organs after radiotherapy of male and female patients was (0.08%–1.8%) and (0.09%–1.9%), respectively. These risk values were 1.5–15.5 times lower when compared to the respective LIRs. The lifetime probability for out-of-field cancer induction in irradiated males and females was (2.5 × 10−4 to 7.7 × 10−2)% and (1.4 × 10−4 to 2.6 × 10−1)%, respectively. The above risks were one to four orders of magnitude lower than the LIRs. Conclusions: The probability for the development of out-of-field malignancies due to radiotherapy for VHs is trivial with respect to the nominal risk for unexposed population. The respective cancer risks to partially in-field organs are smaller than the nominal probabilities but they should not be considered as inconsiderable. These risks may be taken into account during the follow-up of patients treated for a symptomatic VH.

Introduction Few studies on cancer incidence have been conducted since the adoption of the EU 2000/76/EC waste incineration directive which aimed to limit dioxin emission levels to less than 0.1 ng TEQ/m3 before December 31, 2005. Objective To measure cancer incidence among the population exposed to atmospheric emissions from the waste incineration plant near the town of Nice (South-Eastern France), compared to the unexposed population of the Alpes-Maritimes department (A-M). Methods All primary invasive cancers and haematological malignancies diagnosed among AM residents between 2005 and 2014 were recorded. The exposed surface was modeled on an average dioxin deposition model ≥4.25 ng/m2/year. Each case was geolocated and assigned to one of 36 predefined geographic units of exposed area, or one of 462 units in the unexposed area. The adjusted incidence rate, the standardized incidence ratio and the Comparative Morbidity Figure were calculated for two periods: 2005-2009/2010-2014. Results We recorded 80,865 new cancers in the A-M population. Between 2005 and 2009, we observed a higher incidence among exposed women of acute myeloid leukaemia, myelodysplastic syndromes and myeloma and, among exposed men, of soft tissue sarcomas, myeloma and lung cancer. Between 2010 and 2014, there was no excess incidence among women, while among men incidence of myeloma and lung cancer remained higher. Conclusion Only among men, the incidence of myeloma and lung cancer remained higher in the exposed area during the second period. The EU directive resulting in the limitation of atmospheric emissions from incinerators could explain the decrease in incidence of cancers with protracted latency. Consideration of other risk factors and further data collection will be necessary to validate this hypothesis.

The present study investigates the rates of depression, anxiety, somatic distress, and fatigue in a rural population of Abayskiy, Borodulikha and Mayskiy districts exposed to radiation from Semipalatinsk Nuclear Test Site in comparison with the unexposed population of Kurchum district. The sample size included 901 people, of whom 656 were residents of radioecological contaminated areas, while 245 resided at ecologically safe territories and had no radiation exposure in the past. Both study groups had no significant differences concerning age, sex, level of education, smoking habit, and alcohol consumption. The prevalence of depression, anxiety, somatic distress and fatigue in the exposed group was found to be considerably higher than that in the unexposed. Results of logistic regression analysis showed considerable differences in associations between depression and anxiety, as wells as between depression and somatic distress in the exposed group. Besides, depression was significantly associated with general fatigue, reduced activity, physical fatigue, reduced motivation and mental fatigue in the unexposed group. There is a need to tailor public health interventions focused on the identification and management of individuals exhibiting mental distress, including the provision of adequate information about radiation-induced health effects, quality routine check-ups and psychological counseling.

Purpose To assess the risk of contralateral breast and ipsilateral lung cancer induction from forward-planned IMRT for breast carcinoma. Methods The study group included 13 females irradiated for breast cancer with 6 MV photons. The plans were initially generated by using standard fractionated (SF) forward-planned IMRT (50 Gy at 2 Gy/fraction). Hypofractionated (HF) IMRT (42.56 Gy at 2.66 Gy/fraction) was also employed for plan creation. Differential DVHs derived from the treatment plans were used to estimate the patient-specific organ equivalent dose (OED) to the contralateral breast and ipsilateral lung and the relevant lifetime attributable risks of cancer development. These estimates were made with a non-linear mechanistic model. The radiotherapy-induced cancer risks were combined with the lifetime intrinsic risk (LIR) values for unexposed people to determine the patient- and organ-specific relative risk (RR) for second cancer induction. Results The OED of the contralateral breast from SF and HF forward-planned IMRT was up to 0.99 and 0.86 Gy, respectively. The corresponding values for the ipislateral lung were 4.15 and 3.66 Gy. The patient-specific RR range for the contralateral breast and ipislateral lung cancer induction following SF forward-planned IMRT was 1.04–1.10 and 1.60–1.81, respectively. The corresponding RRs from hypofractionated treatment were 1.03–1.09 and 1.53–1.73. Conclusions The treatment of primary breast carcinoma with the use of SF or HF forward-planned IMRT results in increased probabilities for developing secondary malignancies in the healthy contralateral breast or ipsilateral lung compared to the respective LIRs for an unexposed population.

BACKGROUND Studies comparing different forms of asbestos are rare, and limited by the failure to compare results with unexposed populations. We compare autoimmune responses among former workers and residents of the crocidolite mining and milling town of Wittenoom, Western Australia, with an unexposed population. METHODS ANA testing using indirect immunofluorescence was performed on randomly selected serum samples from Wittenoom workers or residents and compared with those from participants of another unexposed cohort study. RESULTS ANA scores were higher in the Wittenoom participants compared with Busselton and the odds of being ANA positive was fivefold greater among Wittenoom participants than Busselton (OR 5.5, 95%CI 2.3-13.0). CONCLUSIONS This study is the first to report increased ANA positivity among persons exposed exclusively to crocidolite. This finding of a high frequency of positive ANA tests among crocidolite-exposed subjects may be an indicator for an increased risk of systemic autoimmune diseases and needs further scrutiny.

Purpose The objective of this study was to estimate the probability for cancer development due to radiotherapy for Graves' orbitopathy with 6 MV x rays. Methods Orbital irradiation was simulated with the MCNP code. The radiation dose received by 10 out-of-field organs having a strong disposition for carcinogenesis was calculated with Monte Carlo methods. These dose calculations were used to estimate the organ-dependent lifetime attributable risk (LAR) for cancer induction in 30- and 50-yr-old males and females on the basis of the linear model suggested by the BEIR-VII report. Differential dose-volume histograms derived from patients' three-dimensional (3D) radiotherapy plans were employed to determine the organ equivalent dose (OED) of the brain which was partly exposed to primary radiation. The OED and the relevant LAR for brain cancer development were assessed with the plateau, bell-shaped and mechanistic models. The radiotherapy-induced cancer risks were compared with the lifetime intrinsic risk (LIR) values for unexposed population. Results The radiation dose range to organs excluded from the treatment volume was 0.1-91.0 mGy for a target dose of 20 Gy. These peripheral organ doses increased the LIRs for cancer development of unexposed 30- and 50-yr-old males up to 1.0% and 0.2%, respectively. The corresponding elevations after radiotherapy of females were 2.0% and 0.4%. The use of nonlinear models gave an OED range of the brain of 482.0-562.5 mGy depending upon the model used for analysis and the patient's gender. The elevation of the LIR for developing brain malignancies after radiotherapy of 30-yr-old males and females reached to 13.3% and 16.6%, respectively. The corresponding increases after orbital irradiation at the age of 50 yr were 6.7% and 8.3%. Conclusions The level of the LIR increase attributable to radiation therapy for GO varied widely by the organ under examination and the age and gender of the exposed subject. This study provides the required data to quantify the elevation of these baseline cancer risks following orbital irradiation.

The objective of present study was to assess relationship between biomarkers of Manganese (Mn) and neuropsychological effects. The study was carried out on 27 welders and 31 ferroalloy smelters as Mn-exposed groups and 30 office workers as unexposed controls. Air Mn concentrations were determined according to NIOSH method 7300. The biological samples were prepared using microwave assisted acid digestion and all samples were analyzed by graphite furnace- atomic absorption spectroscopy (GF-AAS) in order to determine manganese. Questionnaire 16 (Q16) and Cambridge Neuropsychological Test Automated Battery (CANTAB) were used to evaluate the neuropsychological effects. The mean concentrations of air Mn for the welder and ferroalloy smelter groups were 0.023 ± 0.012 mg/m(3) and 0.008 ± 0.005 mg/m(3), respectively. Manganese concentrations in blood, urine, and toenail samples of exposed workers ranged between 1.80-32.60 (µg/l), 1.00-42.50 (µg/l), and 0.10-6.08 (µg/g), respectively. Mean Mn concentrations in all biological samples of cases were significantly higher than unexposed controls (p

The National Center for Education Statistics reported that between 1990–2005 the number of children receiving special education services (SES) rose significantly, and then, from 2004–2012, the number declined significantly. This coincided with the introduction of Thimerosal-containing hepatitis B vaccine in 1991, and the subsequent introduction of Thimerosal-reduced hepatitis B vaccine in the early 2000s. This study examined the potential relationship between infant exposure to mercury from three doses of Thimerosal-containing hepatitis B vaccine and the risk of boys being adversely affected (as measured by receipt of SES). This cross-sectional study examined 1192 boys (weighted n = 24,537,123) 7–8 years of age (born: 1994–2007) from the combined 2001–2014 National Health and Nutritional Examination Survey (NHANES). Survey logistic regression modeling revealed that an exposed population receiving three doses of infant Thimerosal-containing hepatitis B vaccine (weighted n = 11,186,579), in comparison to an unexposed population (weighted n = 704,254), were at an increased risk of receipt of SES. This association was robust (crude odds ratio = 10.143, p = 0.0232), even when considering covariates, such as race and socioeconomic status (adjusted odds ratio = 9.234, p = 0.0259). Survey frequency modeling revealed that receipt of SES for the population that was exposed to three doses of Thimerosal-containing hepatitis B vaccine in infancy (12.91%) was significantly higher than the unexposed population (1.44%) (prevalence ratio = 8.96, p = 0.006, prevalence attributable rate = 0.1147). Despite the limitation of this cross-sectional study not being able to ascribe a direct cause-and-effect relationship between exposure and outcome, it is estimated that an additional 1.2 million boys received SES with excess education costs of about United States (US) $180 billion associated with exposure to Thimerosal-containing hepatitis B vaccine. By contrast, exposure to Thimerosal-reduced hepatitis B vaccine was not associated with an increased risk of receiving SES. Therefore, routine childhood vaccination is important to reduce the morbidity and mortality of infectious diseases, but every effort should be made to eliminate Thimerosal from all vaccines.

Confounding biases study results when the effect of the exposure on the outcome mixes with the effects of other risk and protective factors for the outcome that are present differentially by exposure status. However, not all differences between the exposed and unexposed group cause confounding. Thus, sources of confounding must be identified before they can be addressed. Confounding is absent in an ideal study where all of the population of interest is exposed in one universe and is unexposed in a parallel universe. In an actual study, an observed unexposed population represents the unobserved parallel universe. Thinking about differences between this substitute population and the unexposed parallel universe helps identify sources of confounding. These differences can then be represented in a diagram that shows how risk and protective factors for the outcome are related to the exposure. Sources of confounding identified in the diagram should be addressed analytically and through study design. However, treating all factors that differ by exposure status as confounders without considering the structure of their relation to the exposure can introduce bias. For example, conditions affected by the exposure are not confounders. There are also special types of confounding, such as time-varying confounding and unfixable confounding. It is important to evaluate carefully whether factors of interest contribute to confounding because bias can be introduced both by ignoring potential confounders and by adjusting for factors that are not confounders. The resulting bias can result in misleading conclusions about the effect of the exposure of interest on the outcome.

Confounding is an important source of bias, but it is often misunderstood. We consider how confounding occurs and how to address confounding using examples. Study results are confounded when the effect of the exposure on the outcome, mixes with the effects of other risk and protective factors for the outcome. This problem arises when these factors are present to different degrees among the exposed and unexposed study participants, but not all differences between the groups result in confounding. Thinking about an ideal study where all of the population of interest is exposed in one universe and is unexposed in a parallel universe helps to distinguish confounders from other differences. In an actual study, an observed unexposed population is chosen to stand in for the unobserved parallel universe. Differences between this substitute population and the parallel universe result in confounding. Confounding by identified factors can be addressed analytically and through study design, but only randomization has the potential to address confounding by unmeasured factors. Nevertheless, a given randomized study may still be confounded. Confounded study results can lead to incorrect conclusions about the effect of the exposure of interest on the outcome.

The increase in production of Multi-Walled Carbon Nanotubes (MWCNTs) goes along with growing concerns about health risks. Few, rather small, studies have reported biological effects of MWCNTs in humans including increased concentrations of cardiovascular markers fibrinogen, ICAM1 and IL-6, but findings are largely inconsistent. The objective of this study was to assess the association between occupational exposure to MWCNTs and biomarkers of cardiovascular risk. A cross-sectional biomarker study was performed among workers of a company commercially producing flexible MWCNTs and a matched unexposed population. 12 cardiovascular markers were measured in participants’ blood (phase 1). In a sub-population these measures were repeated after 5 months (phase 2). We analysed associations between MWCNT exposure and biomarkers of cardiovascular risk, corrected for age, BMI, sex and smoking. 22 exposed and 42 unexposed workers were included in phase 1 and a subgroup of 13 exposed workers and 6 unexposed workers in phase 2 of the study. Both in phase 1 and phase 2 we observed an upward trend in the concentration of endothelial damage marker ICAM-1, with increasing exposure to MWCNTs. This finding is supported by significantly elevated monocyte counts among the same workers. No significant associations were found between exposure to MWCNTs and the other cardiovascular markers tPA, Fibrinogen, VCAM-1, IL-6, E selectin, TNF-α and D-Dimer. The results of the present study should be viewed as explorative and requires confirmation in larger studies. Our results for ICAM-1 point towards a potential for endothelial damage due to exposure to MWCNT.

The aim of this study was to assess eight firefighters' exposure to Sthamex 3% AFFF (aqueous film forming foam) in the simulation of aircraft accidents at Oulu airport in Finland. Study was conducted in 2010 before limitation for the use of PFOA and PFOS in AFFFs. Due to prospective limitation also eight commercially available AFFFs were evaluated from occupational and environmental point of view to find substitutive AFFFs for future. The firefighters' exposure to twelve perfluoroalkyl acids (PFAS) was analyzed in order to observe the signs of accumulation during three consecutive training sessions. The firefighters' short-term exposure to 2-butoxyethanol (EGBE) was analyzed by urinalysis of 2-butoxyacetic acid (2-BAA). For the background information also the concentration of PFAS in used AFFF-liquid was analyzed. Fire fighters' serum PFHxS and PFNA concentrations seemed to increase during the three training sessions although they were not the main PFAS in used AFFF. The statistical significance for the elevations was not able to test due to limited size of test group. In two training sessions, the average urinary excretions of 2-BAA exceeded the reference limit of the occupationally unexposed population. In the evaluations of the firefighting foams, non-fluorine based products were favored and the alcohol resistance properties of foams were recommended for consideration due to the increasing use of biofuels.

Introducción: el estrés oxidativo (EO) se relaciona con un desequilibrio entre los sistemas oxidativos y antioxidantes, a favor de los primeros. El aporte de micronutrientes de origen dietario podría proveer de un efecto protector ante la exposición laboral a agentes oxidantes. El objetivo de este trabajo fue determinar si existe relación entre estado nutricional, hábitos higiénico-dietéticos, consumo de macro y micronutrientes y el EO en una población expuesta a agentes oxidantes, en comparación con una población no expuesta. Material y métodos: se estudiaron dos poblaciones de similares características, a excepción de la actividad laboral de una de ellas, constituidas por personas de ambos sexos, de 18 a 30 años de edad. El Grupo Expuesto estuvo constituido por 26 individuos que trabajaban en servicios de fotocopiado. El Grupo no Expuesto por 27 voluntarios que no realizan dicha actividad laboral. Se realizó una encuesta nutricional, dos recordatorios de 24 h, mediciones antropométricas y bioquímicas y determinación de marcadores de EO (Catalasa, relación GSH/GSSG y TBARS). Resultados: los resultados se analizaron mediante estadística multivariada para establecer asociaciones entre variables. Se halló una correlación positiva entre actividad laboral y desbalance oxidativo y entre elevado consumo energético, bajo consumo de alimentos fuente de micronutrientes antioxidantes, sedentarismo, alteración del perfil lipídico y EO; y se encontró una relación positiva entre bajo consumo de energía, perfil lipídico normal y adecuado consumo de frutas y verduras con un estado oxidativo normal. Conclusiones: los resultados muestran que cambios en los hábitos higiénico-dietéticos podrían ofrecer una protección a sujetos expuestos a agentes oxidantes. Fil: Galan, Maria Gimena. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Erben, Melina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Simoniello, Maria Fernanda. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Cátedra de Toxicología y Bioquímica Legal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina

Confounding is very fundamental to the design and analysis of studies of causal effects. A variable is not a confounder if it is not a risk factor to disease or if it has the same distribution in the exposed and unexposed population. Whether or not to adjust for a non confounder to improve the precision of estimation has been argued by many authors. This article shows that if C is a non confounder, the pooled and standardized (log) relative risk estimators are asymptotic normal distributions with the mean being the true (log) relative risk, and that the asymptotic variance of the pooled (log) relative risk estimator is less than that of the stratified estimator.

The fitness of Helicoverpa armigera (Hubner) was determined using demographic studies on the F1 generation that survived after exposure to four sublethal doses (LC50, LC30, LC20 and LC10) of imidacloprid. The effects were assessed on the surviving individuals emerged from sixth-instar larvae that had ingested imidacloprid-treated chickpea pods. Age-specific parameters were found to be highest with the commencement of age and gradually decreased with the progression of age in both the treated and non-treated groups. Survivorship was reduced to 37 days after exposure to the sublethal dose of LC50 when compared with 42 days in groups not exposed to the insecticide. The highest number (17%) of unhatched eggs was recorded in insects treated with the LC50 dose of imidacloprid, whereas 98% of the eggs hatched in the unexposed group. The potential fecundity of the F1 generation females was reduced to 330 eggs/female/generation when treated with the LC50 dose compared with that of the unexposed females. The intrinsic rate of increase was found to be least in insects exposed to the LC20 dose (0.0355 females/ female/day) and highest (0.0470) in the unexposed group. It took 38.83 days for H. armigera to complete one generation in the unexposed population, while this was reduced to 33.94 days after exposure to the sublethal dose of LC50 The longevity of adults decreased when the larvae were exposed to the sublethal dose of imidacloprid. The developmental time of pre-pupae and pupae significantly decreased and was least when exposed to the highest sublethal dose of the insecticide. Thus, at sublethal doses, imidacloprid caused a significant reduction in the survival and fecundity as well as increased mortality of H. armigera in the subsequent generation after exposure to the insecticide. In conclusion, imidacloprid can be successfully incorporated into integrated pest management of H. armigera.

High performance thin-layer chromatography (HPTLC)-densitometry was used to characterize and quantify neutral and polar lipids in Biomphalaria glabrata snails subjected to either Echinostoma caproni and Schistosoma mansoni miracidia coexposure, or single exposure to each of these trematode parasites. Observations on survival and fecundity were made on an unexposed population (2 cultures of 25 snails each); a population exposed exclusively to S. mansoni(2 cultures of 25 snails, each exposed to 6 miracidia per snail); a population exposed exclusively to E. caproni (2 cultures of 25 snails, each exposed to 10 miracidia per snail); and a population exposed to S. mansoni and one week later exposed to E. caproni (2 cultures of 25, each exposed to 10 E. caproni miracidia and 6 S. mansonimiracidia per snail). Each culture contained 800 mL of artificial spring water; snails were maintained at 25 ± 1°C and fed boiled romaine lettuce ad libitum. A sample of each population was necropsied at 2, 4, 6, and 8 weeks post...

Traditional environmental risk assessment methodologies, including benchmark dose (BMD) estimation, were originally developed to be used with animal toxicology data. We discuss some problems that can occur when toxicology-based methods are applied to human cohort studies, and we propose a new method for BMD risk estimation adapted to epidemiological data. Instead of extrapolating to zero-dose levels to estimate risk in an unexposed population, our proposed alternative involves specifying a nonzero background exposure level instead. To account for uncertainty in that level, we can average modified BMDs over a distribution of exposure levels. We apply our modified BMD method to analyze data from a cohort study designed to assess the effects of prenatal polychlorinated biphenyl (PCB) exposure on cognitive ability in young children. Copyright © 2013 John Wiley & Sons, Ltd.

Arsenic in drinking water presents a serious public health problem in Serbia, but its relationship with diabetes has not been studied previously. The aim of this study was to explore the association between exposure to arsenic in drinking water and the occurrence of type 2 diabetes in Middle Banat region, Serbia. This cross-sectional study comprised two populations. Exposed population in Middle Banat region consumes drinking water with arsenic (mean = 56 μg/L); unexposed population from six regions in Central Serbia consumes arsenic below detection limit (2 μg/L). Newly diagnosed cases of type 2 diabetes were obtained from the National Registry of Diabetes in 2008. The Registry included age, gender, family history of diabetes, presence of overweight, central obesity, cholesterol and triglyceride levels. In addition, the number of cases of diabetes reported in years 2006, 2007 and 2009 was used to calculate standardized incidence rates for both populations. Two populations were comparable by age, family history of diabetes and prevalence of overweight persons. Unexposed population was more likely to have central obesity, and high total cholesterol and triglycerides. Standardized incidence rates of type 2 diabetes were higher in exposed population. Odds ratios for type 2 diabetes were significantly higher for the exposed population, both men and women, in the period from 2006 to 2009, when compared with the unexposed population. The population from Middle Banat region, consuming drinking water with low levels of arsenic, was at higher risk for the occurrence of type 2 diabetes in comparison to the unexposed population in Central Serbia.

Background Car painters are exposed to Volatile organic compounds during their work. Volatile organic compounds are a mixture of different hydrocarbons that after inhalation exposure or through skin absorption have adverse effects on the central nervous system (CNS), skin and respiratory system. Conservation programs and supervising and monitoring the health of the workers are necessary to reduce exposure before creating synergistic effects of toxic substances in the workplace. Methods In this case-control study to evaluation of adverse health effects of VOCs on exposed persons,122 workers working in car painting workshops and122 people from the unexposed population as control in Arak-Iran were studied. Total Volatile organic compounds in their workshops were measured and using a designed questionnaire, demographic and respiratory symptoms of poisoning with VOCs were collected. Then, using a portable spirometer machine, Pulmonary function indices of workers, mainly “VC, FVC, FEV1 were measured. After collecting desired information, with spss software, statistical analysis was performed. Results The workers in car painting workshops were exposed to 5.17 ppm TVOC during their work. The mean pulmonary function indices, VC, FVC FEV1 in cases 78, 178 and 44 ml were lower than the control group respectively. There was a statistically significant difference in Tiffeneau-Pinelli index (FEV1/FVC) between the two groups (pv Conclusion The results in this study indicate these workers during daily activities are exposed to higher than the permissible level of VOC. So suitable ventilation in the work place, engineering and administrative control, and regular training to promote workers’ awareness of health hazards of the chemicals to all workers are necessary.

Background Dichlorodiphenyltrichloroethane (DDT) has been the centre of debate for several decades with a global call for a ban on its use, while organophosphates (OP) and pyrethroids are used extensively in agriculture. Both DDT, OPs and pyrethroids are being used extensively in South Africa in malaria control and small-scale agriculture. There is limited information from Africa on the adverse associations between DDT, OPs, pyrethroids and reproductive and neurobehavioural health outcomes. Aim The aim of this study is to identify the impact of DDT, OP and pyrethroid exposure on the reproductive health of pregnant women and the neurobehavioural health outcomes of their offspring. Method This longitudinal study with a 3 year follow-up period is being conducted in the uMkanyakude (exposed population) and uMgungundlovu (unexposed population) districts of KwaZulu-Natal, South Africa. A total of 350 pregnant women attending antenatal clinics at the district hospital and respective primary health clinics will be recruited (February – December 2016) and followed for 3 years. Maternal interviews (demographic, exposure and health data), and biomonitoring of exposure to pesticide (urine and blood) will take place at recruitment and annually for the duration of the study. Infant clinical and neurobehavioural assessments together with direct home observations to assess child development will take place. Biomonitoring of exposure to DDT, OPs and pyrethroids will take place at birth and annually for the duration of the study. Results and discussion Data is currently being collected and information from the baseline recruitment interviews will be presented for the available women. Demographic, occupational and environmental pesticide exposure together with reproductive histories will be presented for the recruited cohort. This study will contribute knowledge on the relationship between DDT, OPs, pyrethroids and reproductive and neurobehavioural health outcomes in an African population.

To evaluate measures of health-related quality of life in a cohort study in Taiwan to assess late health effects of protracted low-dose-rate γ-radiation exposure during 1982 to the mid-1990s.In 2004, 1,407 cohort subjects were evaluated by a self-measured World Health Organisation-Brief quality of life Questionnaires (WHOQOL-BREF Taiwan version) during an annual medical check-up in a hospital. Results of their health-related quality of life (HRQoL) in physical, psychological, social relationship and environmental domains were compared with an unexposed reference population in the same city.The exposed population was shown to have significantly lower quality of life (QOL) scores in physical, psychological and social relationship domains, but not in the environmental domain compared to the unexposed population. These findings were observed in all age groups with the greatest decrease found among those younger than 25 years old. Female subjects were shown to have larger decrease than male subjects.More than 10 years after being informed of radiation exposure, the exposed populations were observed to have significantly lower perception of HRQoL even though no biomedical effects were apparent. It is recommended that appropriate intervention be carried out in the follow-up of post-event rehabilitation for the radiation exposed.

Background Breastmilk is the recommended form of enteral nutrition for all infants. Infants nourishing on breastmilk contaminated with lead are at high risk of exposure to this neurotoxic heavy metal. The aim of this study was to screen lead concentrations in samples of breastmilk obtained from women living in three main regions of the West Bank and to investigate the sociodemographic characteristics associated with high lead concentrations. Methods In this cross-sectional study, breastmilk samples were collected from breastfeeding women living in Nablus, Ramallah, and Jerusalem. The participants' sociodemographic characteristics were recorded, and the lead concentration in breastmilk samples were quantified using a graphite furnace atomic absorption spectrophotometer. Ethical approval was obtained from the Institutional Review Board of An-Najah National University, and all participants provided written informed consent. Findings Breastmilk samples were obtained from 89 women. The median lead concentration was 4 μg/L (range 2–12 μg/L). The lead concentration was higher than WHO's safety limits for occupationally unexposed population in 17 (19%) samples. Lead concentrations were also significantly higher in samples obtained from women living in refugee camps and cities (p=0·003) than in women living in villages, higher in women with low monthly household income than in women with high monthly household (p=0·020), higher in women living in houses with peeling paint than in women living in houses with no peeling paint (p=0·026), higher in women who worked in agriculture for more than 3 years than in women who worked in agriculture for less than 3 years or less (p=0·005), and higher in women who frequently used eye kohl than in women who did not (p=0·004). Multiple linear regression analysis showed that using eye kohl was a significant predictor (p=0·040) of lead concentration in breastmilk above WHO's safety limits. Interpretation In this study, about one-fifth of women had concentrations of lead in their breastmilk above the WHO's safety limits. Authorities need to implement measures to eliminate or reduce lead exposure, especially in refugee camps and cities. Eye kohl preparations marketed in the occupied Palestinian territory should be screened for lead content. Funding None.

Arsenic Exposure through Drinking Water and its Effect on Pregnancy Outcome in Bengali WomenTwelve districts of the state of West Bengal, India are affected by arsenic (As) and millions of individuals are consuming As-contaminated groundwater. The probable adverse effects of As on pregnancy outcome (stillbirth and miscarriage) are yet to be properly studied. The present investigation is an attempt to understand the effects of As exposure on the pregnancy outcome in Bengali women exposed to As through drinking water and residing in different villages in North 24 Parganas District of West Bengal. The results show a significantly higher rate of stillbirths and miscarriages than those in the unexposed population.

The prevalence of disease in many populations is often low. For example, the prevalence of tuberculosis, brucellosis, and bovine spongiform encephalopathy range from 1 per 100,000 to less than 1 per 1,000,000 in many countries. When an outbreak occurs, epidemiological investigations often require comparing the prevalence in an exposed population with that of an unexposed population. To determine if the level of disease in the two populations is significantly different, the epidemiologist must consider the test to be used, desired power of the test, and determine the appropriate sample size for both the exposed and unexposed populations. Commonly available software packages provide estimates of the required sample sizes for this application. This study shows that these estimated sample sizes can exceed the necessary number of samples by more than 35% when the prevalence is low. We provide a Monte Carlo-based solution and show that in low-prevalence applications this approach can lead to reductions in the total samples size of more than 10,000 samples.

Purpose There are a limited number of case reports confirming the radioiodine (I-131) presence in tears and only a few case reports of lacrimal gland dysfunction after I-131 therapy. This study was designed to clarify whether lacrimal gland function can be affected by I-131 therapy. Materials and methods We studied 100 eyes of 50 patients who had received high doses of I-131 for treatment of differentiated thyroid carcinoma and 100 eyes of 50 age- and sex-matched control individuals without a history of interfering conditions. The exposed group was studied at least 3 months after their last I-131 therapy. Dry eye symptoms and Schirmer test values (wetting level in millimeters per 5 minutes) of an exposed group were compared with those of an unexposed group. Results Fifty-one percent of the exposed eyes and 50% of the unexposed ones revealed at least 1 of the dry eye symptoms. There was no significant difference in symptoms between 2 groups, except for burning sensation and eye redness, which were significantly higher in the exposed eyes. A lower Schirmer test value was noted in the exposed group, 14.5 +/- 10.8 mm, when compared with that in controls, 18.2 +/- 11.0 mm (P = 0.016), and the relative risk of an abnormal Schirmer test in exposed cases to control group was 1.78 +/- 0.62. Correlation coefficient analysis showed no significant relationship between Schirmer test values and cumulative doses of administered I-131. Conclusions Reduction in the tear secretion from lacrimal glands is seen after high-dose I-131 therapy; however, their symptoms are no greater than an unexposed population.

In the present paper, a multiple logistic model has been proposed to estimate the exposure-specific incidence rates of several dichotomous etiologic factors from case-control data. The relative probability of falling in a given exposure level with respect to the unexposed population for cases is expressed as a logistic function of the exposure levels (1 if exposed, 0 if not) of these factors. The odds ratio of the exposure category of cases relative to the controls comes out to be an exponential function of the exposure levels. It is shown how the maximum likelihood estimates of the logistic parameters can be obtained. The term ‘marginal effect’ of a factor is introduced. This is the effect of a factor A in the presence of one or more of other factors. The difference SA between the marginal effect and the individual effect of a factor A is the increase in the effect of A when it interacts with other factors. A simple relationship has been established between the Hogan et al. measure and the increases SA, SB, … of two or more factors. Several numerical examples illustrate the results.

The paper discusses the content of elements in hair of subjects studied over several years. The study was performed on 5 subjects (N=28) that lived together or were family related. The elemental composition of hair of the studied subjects was compared with the average content of the population living in the same urban area (Wroclaw city, south-west Poland), with the population of a non-industrialized area in Poland (Silesian Beskid), as well as with the population of north-east Sweden and Rio de Janeiro. When comparing the composition of hair from the studied subjects with the people living in the same city, it was found that the differences resulted mainly from different living habits (Na, Si, Co, Fe, Mn, Zn) and local exposure (Pb, Cd, Al). When comparing with the reference material for unexposed population, it was found that the studied subjects were exposed to Al. Time profile of element contents in hair of a given person showed that the level changed significantly (even several fold) with changes of living habits or environmental exposure. Also, it was found that there were similar tendencies in the accumulation of the majority of elements by people that lived together. The effect of living habits on the level of a given element was found to be stronger than the influence of either sex or family relationship. The paper also discusses inter-element interactions within the studied group. Statistically significant (p

Chromosome aberration analyses were performed on blood samples from 165 active underground uranium miners between 1981 and 1985. After decommissioning the mine in 1997 chromosome aberration analyses were also included in the medical laboratory investigations of health conditions of 141 subjects between 1998 and 2002 within the framework of a follow-up-study. The numerical data are presented as functions of the exposure categories expressed in working level month up to 600. In the active groups the dicentric level was 7 to 12 times higher than in the unexposed population, the acentrics also higher with more than an order of magnitude, the frequency of total aberrations--including dicentrics, acentrics, rings, deletions, minits and numerical aberrations, i.e. both chromatid and chromosome type of aberrations were also well above the control level. In the group of former uranium miners although there were slight decreases in the dicentrics after 8 to 25 yr, the values were not significantly different from the values of active miners. The frequency of deletions was also maintained in the post-mining period. The frequency of acentrics, however, decreased significantly, but even the lowest values remained 2-3 times higher than the values in the unexposed population.The possibility is suggested that for the long-term persistence of cytogenetic alterations the permanent production and presence of clastogenic factors might be responsible. The comparison of the two datasets suggest a long-term persistence of cytogenetic alterations above the population average values in a large fraction of persons investigated.

The role of nutritional factors in arsenic metabolism and toxicity is not clear. Provision of certain low protein diets resulted in decreased excretion of DMA and increased tissue retention of arsenic in experimental studies. This paper reports a prevalence comparison study conducted in Bangladesh to assess the nutritional status among the chronic arsenic exposed and unexposed population. 138 exposed individuals diagnosed as arsenicosis patients were selected from three known arsenic endemic villages of Bangladesh and age, sex matched 144 unexposed subjects were randomly selected from three arsenic free villages. The mean arsenic concentration in drinking water for the exposed and unexposed population was 641.15 and 13.5 microg L(-1) respectively. Body Mass Index was found to be lower than 18.5, the cut off point for malnutrition, in 57 (41.31%) out of 138 exposed arsenicosis cases and 31 (21.53%) out of 144 unexposed individuals. The crude prevalence ratio (or risk) was 1.92 (95% CI = 1.33-2.78) for poor nutritional status among the arsenicosis cases compared to the unexposed population. The findings of this study add to the evidence that poor nutritional status may increase an individual's susceptibility to chronic arsenic toxicity, or alternatively that arsenicosis may contribute to poor nutritional status.

Objectives This study aimed at developing a model for determining the work-relatedness of low-back pain for a worker with low-back pain using both a personal exposure profile for well-established risk factors and the probability of low-back pain if the worker were unexposed to these factors. Methods After a systematic review of the literature, the pooled prevalence of low-back pain in an unexposed population and the pooled odds ratio (OR) for each risk factor was calculated in a meta-analysis using a random effect model. An unbiased risk estimate for each risk factor was obtained by correcting the pooled OR for confounding by other risk factors. The probability of low-back pain was calculated with a logistic regression model. The input was (i) the age-dependent prevalence when not exposed and (ii) the unbiased risk estimates per risk factor of low and high exposure. The etiologic fraction was calculated to determine the level of work-relatedness. Results The pooled prevalence for low-back pain among unexposed subjects was 22%, 30%, and 34% for the＜35-year, 35-to-45-year, and ＞45-year age categories, respectively. The pooled OR was 1.51 [95% confidence interval (95% CI) 1.31-1.74] for manual materials handling, 1.68 (95% CI 1.41-2.01) for frequent bending or twisting, 1.39 (95% CI 1.24-1.55) for whole-body vibration, and 1.30 (1.17-1.45) for job dissatisfaction. For high exposure to manual materials handling, frequent bending or twisting, and whole-body vibration, the pooled OR was 1.92, 1.93, and 1.63, respectively. Conclusions The model is the first that estimates the probability of work-relatedness for low-back pain for a given worker with low-back pain seen by a general practitioner or an occupational health physician.

This study was conducted to investigate the possible long-term health effects, in particular carcinogenic effects, of occupational exposure to the organochlorine insecticides dieldrin and aldrin. We updated an earlier cohort mortality study of 570 employees involved in the production of these insecticides. All of the employees had worked in the production plants between 1 January 1954 and 1 January 1970 and were followed for cause-specific mortality until 1 January 2001. Based on dieldrin levels in blood samples taken during the exposure period, available for 343 workers, individual estimates of the total intake of dieldrin were estimated for all individual subjects in the cohort. The estimated total intake ranged from 11 to 7755 mg of dieldrin, with an average of 737 mg. One hundred and seventy-one workers had died before 1 January 2001, compared with an expected number of 226.6, giving a standardized mortality ratio (SM R) of 75.6 [95% confidence interval (CI): 64.6-87.7]. This deficit in total mortality was mainly attributable to a deficit in cardiovascular disease mortality, but cancer mortality was also lower than expected. The observed number of deaths from rectal cancer was significantly higher than expected (SM R 3/4-300.0; 95% CI: 109.5-649.3), but was most pronounced in the low-intake subgroup and appears to be unrelated to exposure to dieldrin and aldrin. This study reinforces the earlier findings that occupational exposure of workers to significant amounts of dieldrin and aldrin has not led to a higher cancer mortality than would be found in an unexposed population.

Objectives: to know the effect participation in prenatal class to the practice of early initiation breastfeeding in Sisir health care center-Batu. Materials and Methods: This research was an analytical study with cohort retrospective design. The population in this study was divided into two populations, exposed populations were mothers who attend prenatal classes during the last pregnancy and unexposed population were mothers never attend prenatal classes. Sample size was 32 respondent. Data were analyzed by chi square test. Results: The results of the bivariate analysis of age (p value = 0.229), education (p value = 0.1790, parity (p value = 0.011), knowledge (p value = 0.047), attitude (p value = 0.893), history of labor (p value = 0,021), information (p value = 0.472), birth attendants (p value = 0.017), the place of delivery (p value = 0.003), participation in prenatal classes (p value = 0.27), decision makers (p value = 0.137), counseling during pregnancy (0.16) The analysis showed significant variable is the parity (p = 0.011), knowledge (p = 0.047), birth attendants (p = 0.017), the place of delivery (0.003), history of labor (p = 0.021), counseling during pregnancy (p = 0.010). Conclusion: There is no effect of the mother's participation in the prenatal class to the practice of early initiation breastfeeding, but the prenatal classes effect mothers knowledge which influence the practice of early initiation breastfeeding.

Cornfield developed an inequality on the observed relative risk, R O, between an exposed and unexposed group, which could be explained by an unmeasured confounder, U. To be precise, R O is no greater than the ratio of the prevalence of U in the exposed to that in the unexposed population. It is also true that R O ≤ R U, where R U is the ratio of risk in those with U compared to those without U. We discuss a sharper bound on R O, which can be computed when information on R U and on the prevalences of U in the exposed and unexposed populations are available. We also consider related bounds for risk differences and sensitivity analyses for tests of hypotheses in the presence of an unmeasured confounder. Keywords: Cornfield's inequality; confounder; confounder risk ratio; sensitivity analysis; missing covariate

Human health risks at workplaces in platinum industry can emerge from inhalative exposure, explicitly allergic asthma caused by halogenated complex platinum salts. Airborne concentrations of platinum (Pt) are varying (up to 20 µg Pt/m3) among workplaces, but reliable ambient measurements are not easy because of short-term concentration peaks and sensitisation to platinum salts can occur even in low exposure levels. Biological monitoring of Pt in urine gives clear evidence for exposure because values are 100–1,000-fold higher compared to unexposed population (1–10 ng/l). Regular medical examinations are recommended to determine specific sensitisation and work related allergic symptoms. In pharmacies and hospital care units cancerogenic platinum compounds like the drug cisplatin are handled in cancer therapy. In such settings exposure levels are low and urinary Pt concentrations close to those of unexposed people. Therefore, confounders like dental noble metal alloys can have a significant influence and have to be taken in account. Wipe samples have been introduced in pharmacies and hospitals and are an appropriate method to detect contaminated spots and help to reduce exposure to cancerogenic platinum compounds through improvement of work place safety measures.

A range of invertebrates have become adapted to certain toxic metals, such that, in the presence of the contaminant, some measure of their performance, typically growth or reproduction, is superior to that of an unexposed population. Under such a toxic stress, a population with a history of exposure might outperform a naive population in competition for limited resources. This study compared the shell growth of laboratory-bred juveniles from six populations of Helix aspersa with different histories of exposure to Pb. In 10 trials using various combinations of two populations, the snails competed for a limited supply of food that contained either no Pb or 500 μg/g −1 Pb, for 98 days. Each trial consisted of 10 juveniles, five from each population and was replicated four times. Nearly all of the food provided was consumed quickly after presentation. The total amount of shell growth within each replicate (the sum of the mean growth of the two populations) was highly consistent between trials so that the total amount of shell built was limited by food availability. The presence of Pb in the diet caused no measurable depression of shell growth and exposure history did not appear to confer any competitive advantage or disadvantage in any of the trials. One population consistently grew faster than its competitors in every trial of which it was a part. Shell growth tended to be greater in smaller juveniles. Snail activity is known to be inhibited at high densities and this may have contributed to the lower incremental growth in individuals kept at the higher densities. The competitive advantage enjoyed by one population may be primarily determined by their activity or perhaps their Ca metabolism.