Search

Anthropogenic changes to forest cover have been linked to an increase in zoonotic diseases. In many areas, natural forests are being replaced with monoculture plantations, such as oil palm, which reduce biodiversity and create a mosaic of landscapes with increased forest edge habitat and an altered micro-climate. These altered conditions may be facilitating the spread of the zoonotic malaria parasite Plasmodium knowlesi in Sabah, on the island of Borneo, through changes to mosquito vector habitat. We conducted a study on mosquito abundance and diversity in four different land uses comprising restored native forest, degraded native forest, an oil palm estate and a eucalyptus plantation, these land uses varying in their vegetation types and structure. The main mosquito vector, Anopheles balabacensis, has adapted its habitat preference from closed canopy rainforest to more open logged forest and plantations. The eucalyptus plantations (Eucalyptus pellita) assessed in this study contained significantly higher abundance of many mosquito species compared with the other land uses, whereas the restored dipterocarp forest had a low abundance of all mosquitos, in particular, An. balabacensis. No P. knowlesi was detected by PCR assay in any of the vectors collected during the study; however, P. inui, P. fieldi and P. vivax were detected in An. balabacensis. These findings indicate that restoring degraded natural forests with native species to closed canopy conditions reduces abundance of this zoonotic malarial mosquito vector and therefore should be incorporated into future restoration research and potentially contribute to the control strategies against simian malaria. [ABSTRACT FROM AUTHOR]

We investigated the association of allergic diseases and epilepsy with risk of brain tumours, in Interphone, a 13-country case–control study. Data were obtained from 2693 glioma cases, 2396 meningioma cases, and 1102 acoustic neuroma cases and their 6321 controls. Conditional logistic regression models were used to estimate pooled odds ratios (ORs) and their respective 95% confidence intervals (CIs), adjusted for education and time at interview. Reduced ORs were observed for glioma in relation to physician-diagnosed asthma (OR = 0.73; CI 0.58–0.92), hay fever (OR 0.72; CI 0.61–0.86), and eczema (OR 0.78, CI 0.64–0.94), but not for meningioma or acoustic neuroma. Previous diagnosis of epilepsy was associated with an increased OR for glioma (2.94; CI 1.87–4.63) and for meningioma (2.12; CI 1.27–3.56), but not for acoustic neuroma. This large-scale case–control study adds to the growing evidence that people with allergies have a lower risk of developing glioma, but not meningioma or acoustic neuroma. It also supports clinical observations of epilepsy prior to the diagnosis of glioma and meningioma. [ABSTRACT FROM AUTHOR]

Identify the perceived benefit of mental health service use for two adolescent populations: (i) those who had considered getting help from a mental health service but had not yet done so, and (ii) those who had previously contacted or accessed a mental health service but not continued with care. Cross-sectional online survey of adolescents aged 14–18 years currently residing in Perth, Western Australia. Those who had previously accessed a mental health service but not continued with care often had less favourable perceptions of service benefit. Participants in both populations considered that mental health service use was least likely to be beneficial for conduct-related behaviours. Participants in both population groups from single-carer households or identifying as LGBTIQ reported a higher perceived benefit of mental health services. Our study highlights potential gaps in adolescent knowledge regarding mental health help-seeking. Perceptions of service benefit were often no different or less favourable amongst those who had previously accessed a mental health service but not continued with care. The range of sociodemographic factors significantly associated with perceived benefit across both populations in the sample indicates subpopulations of young people may require extra support within the system. [ABSTRACT FROM AUTHOR]

The aim of this study is to identify factors that stopped, discouraged or delayed mental health help-seeking in adolescents. An Online survey of 113 adolescents aged 14–18 years old, living in Perth, Western Australia, was conducted. For participants who had not yet accessed a mental health service, the top barrier was 'Having no-one who could help me get professional care' (62%). For participants who had previously accessed a mental health service, the top barrier was 'Previous experiences with a mental health service were not helpful' (63%). Major reported barriers in this population included financial costs, negative past experiences and having no one to help access professional care. [ABSTRACT FROM AUTHOR]

Defining the linkages between landscape change, disease ecology and human health is essential to explain and predict the emergence of Plasmodium knowlesi malaria, a zoonotic parasite residing in Southeast Asian macaques, and transmitted by species of Anopheles mosquitos. Changing patterns of land use throughout Southeast Asia, particularly deforestation, are suggested to be the primary drivers behind the recent spread of this zoonotic parasite in humans. Local ecological changes at the landscape scale appear to be increasing the risk of disease in humans by altering the dynamics of transmission between the parasite and its primary hosts. This paper will focus on the emergence of P. knowlesi in humans in Malaysian Borneo and the ecological linkage mechanisms suggested to be playing an important role. [ABSTRACT FROM AUTHOR]

Simulated lung fluids are solutions designed to mimic the composition of human interstitial lung fluid as closely as possible. Analysis of mineral dusts using such solutions has been used to evaluate the respiratory bioaccessibility of various elements for which solubility in the lungs is a primary determinant of reactivity. The objective of this study was to employ simulated lung fluid analysis to investigate the respiratory bioaccessibility of nickel in soils. Current occupational guidelines in Australia regulate nickel compounds in terms of water solubility, though this may not be an accurate estimation of the total nickel that will dissociate in the lungs. Surface soils were collected from the city of Kalgoorlie in Western Australia, the site of an operational nickel smelter and metal mining activities. The fraction of the samples less than 10 μm was extracted from the soil, and it was this sub-10-μm fraction that was found to hold most of the total nickel present in the soil. The fine fraction was analyzed using a simulated lung fluid (modified Gamble's solution) to isolate the nickel phases soluble in the lungs. In addition, a sequential extraction was employed to compare the bioaccessible fraction to those dissolved from different binding forms in the soil. In all samples, the simulated lung fluid extracted more nickel than the two weakest leaches of the sequential extraction combined, providing a more representative nickel bioaccessibility value than the current water leach method. [ABSTRACT FROM AUTHOR]

Previous studies have linked poor mental human health with environmental degradation, but none have assessed additional diseases that may co-exist with these mental disorders. In previous work, depression was found to be associated with a major form of environmental degradation; dryland salinity. However, little is known about diseases co-morbid with depression in this environmental setting. In rural Australia, dryland salinity is a major form of environmental degradation contributing widely to deterioration and non-viability of farmland. Using georeferenced health record data, Bayesian spatial methods were used to determine the relationship between dryland salinity and a range of human health outcomes. Initial modelling found an increased relative risk for asthma, suicide and ischaemic heart disease in relation to dryland salinity (adjusted for Indigenous and socio-economic status). However, in this follow-up study, a further evaluation of the role of co-morbidities in this population revealed that: (i) the presence of depression was consistently linked to residence in areas with high salinity and (ii) the association of asthma, suicide and heart disease with salinity was most likely attributable to the co-morbidity of the conditions with depression. Given the predicted increase in dryland salinity and the elevated relative risk of depression in impacted areas, the relative risk of the co-morbid conditions can be expected to increase in rural areas in the future, further adding to the burden of disease associated with environmental degradation. [ABSTRACT FROM AUTHOR]

Bushfire smoke contains an array of organic and inorganic compounds, including respirable and inspirable particles, aldehydes, and carbon monoxide. These compounds have been found to be a health hazard for firefighters in the United States. Despite the high frequency of bushfires in Australia, analyses of bushfire smoke components are scarce. As part of an occupational health study investigating the respiratory health effects of bushfire smoke in firefighters, air toxics sampling was undertaken in a smoke chamber and during prescribed burns. Levels of formaldehyde and acrolein were demonstrated at respectively 60% and 80% of the Short Term Exposure Limit in the smoke chamber. Carbon monoxide levels exceeded the peak limit of 400 ppm significantly. Although concentrations were lower during the prescribed burns, the study shows that Australian bushfire smoke contains air toxics of concern and provides justification for further research into the levels of air toxics measured at bushfires and the associated health impacts. [ABSTRACT FROM AUTHOR]

Land use change has the potential to cause severe ecosystem degradation and drive changes in disease transmission and emergence. Broadscale clearing of native vegetation for agriculture in southwestern Australia has resulted in severe ecosystem degradation, which has been compounded by the subsequent development of large areas of dryland salinity. The mosquito-borne disease, Ross River virus (RRV), has been noted as a potential adverse human health outcome in these salinity affected regions. The association between dryland salinity and RRV disease was therefore tested by undertaking a spatial analysis of disease notification records using standard and Bayesian techniques. To overcome inherent limitations with notification data, serological RRV antibody prevalence was also investigated. Neither method revealed a significant association with dryland salinity, however, the spatial scale imposed limited the sensitivity of both studies. Thus, further multidisciplinary studies are required to overcome these limitations and advance understanding of this ecosystem health issue, particularly using variables that can be investigated on a finer scale. [ABSTRACT FROM AUTHOR]

Objectives: To assess the risks for adult-onset acute leukemia associated with electrical employment in New Zealand.Methods: The occupational and environmental exposures histories of 110 incident leukemia cases and 199 general population controls were compared. The cases were recruited through referrals to treatment centers in New Zealand between 1989 and 1991. For subjects classified as having worked in one or more of the "electrical occupations," the degree of exposures to extremely low frequency electromagnetic fields (ELF-EMFs) was assessed in detail using a job-exposure matrix.Results: An odds ratio of 1.9 (95% Cl 1.0-3.8) was found for subjects who had ever worked in an electrical occupation. Significantly increased risks for leukemia are seen amongst welders/flame cutters (OR = 2.8 (95% CI 1.2-6.8)) and telephone line workers (OR = 5.81 (95% CI 1.2-27.8)). The excess leukemia risk appeared to be confined to acute non-lymphocytic leukemia (OR=2.31 (95% CI 1.2-4.6)), in comparison to acute lymphoblastic leukemia (OR = 0.9 (95% CI 0.3-2.9)) but for the latter category the numbers were very small. A dose-response effect was also found, with acute leukemia risk rising with increasing occupational magnetic field exposure, based on both current and historical occupational field exposure estimates.Conclusions: The findings of the current study indicate a significantly elevated risk of acute leukemia for electrical workers overall, and for the specific occupational categories of welders/flame cutters and telephone line workers. A dose-response effect was also found, indicating that acute leukemia risk was related to historical and current magnetic field exposures in an occupational context. [ABSTRACT FROM AUTHOR]

Though significant research highlights higher rates of mental ill-health and substance use among trans, non-binary and gender diverse (henceforth ‘trans’) young people, little research has considered patterns, contextual characteristics, and correlates of co-occurring experiences of mental ill-health and substance use among trans young people. Using data from the Trans Pathways study, we used prevalence ratios and age- and gender-adjusted logistic regression models to examine prevalence and differences of co-occurring substance use (past six-month cigarette use, alcohol use, and other drug use) and contextual characteristics of substance use (past six-month solitary alcohol and/or drug use, substance use for coping) by mental ill-health (depression disorder, anxiety disorder, past 12-month self-harm thoughts and behaviours, suicidal thoughts, planning, and attempt/s). Age- and gender-adjusted models assessed associations between co-occurring depressive and anxiety disorders and recent cigarette, alcohol, and other drug use (six co-occurring items total) and 18 interpersonal stressors. Significantly increased odds of smoking or recent use of cannabis or sedatives was observed among trans young people reporting depressive disorder, anxiety disorder (aORs ranging 1.8–3.1). Trans young people who reported recent smoking or use of cannabis, inhalants, or sedatives, had 40% to 80% reduced odds of past 12-month self-harm thoughts, self-harm behaviours, suicidal thoughts, and suicide attempt/s (aORs ranging 0.2–0.6). On the other hand, solitary alcohol and/or other drug use and substance use for coping was significantly associated with increased odds of all mental ill-health outcomes. Issues with school, secure housing, and intimate partner abuse were the most robust correlates of co-occurring mental ill-health and substance use. Trans young people using substances, especially cigarettes, cannabis, and sedatives, often so do with co-occurring experiences of depression and anxiety though limited substance use in more ‘social’ contexts may confer benefits for preventing self-harm and suicide thoughts and behaviours. Continued research in partnership with trans young people is warranted to conceptualise more nuanced and precise conceptual parameters of trans-affirming substance use harm reduction approaches. [ABSTRACT FROM AUTHOR]

The article reports on the evolution of the geology profession. Medical geology is becoming a field of science that requires integration of other disciplines. The human cultural evolution has a pattern of specific disease burdens throughout time. Agricultural, industrial and global advances have eliminated some health issues while creating new ones. Detailed global science databases of the future may allow medical geologists to better research and recommend use of natural resources. The biological systems on the planet can only improve. Epidemiological challenges will continue as the scope of geology incorporates environmental, social, medical and political sciences.