Critical reviews of exposure assessment in carcinogenic hazard identification: the IARC Monographs experience.

OBJECTIVES: To summarise the rationale, workflow and recommendations for the conduct of exposure assessment critiques in key human studies evaluated for International Agency for Research on Cancer (IARC) Monographs on the Identification of Carcinogenic Hazards. METHODS: Approaches to evaluating exposure assessment quality in human cancer and mechanistic studies were reviewed according to the precepts outlined in the IARC Monographs Preamble, using two agents as case studies. Exposure assessment 'domains', that is, salient aspects of exposure assessment for the agent under evaluation, were selected for review across the key human studies. RESULTS: The case studies of night shift work (volume 124) and 1,1,1-trichloroethane (volume 130) used a common approach, tailored to the agents' specific exposure scenarios, to evaluate exposure assessment quality. Based on the experiences of IARC Working Groups to date, the implementation of exposure assessment critique requires the need for agent-specific knowledge, consideration of the validity of time-varying exposure metrics related to duration and intensity, and transparent, concise reviews that prioritise the most important strengths and limitations of exposure assessment methods used in human studies. CONCLUSIONS: Exposure assessment has not historically been a fully appreciated component for evaluating the quality of epidemiological studies in cancer hazard identification. Exposure assessment critique in key human cancer and mechanistic studies is now an integral part of IARC Monographs evaluations and its conduct will continue to evolve as new agents are evaluated. The approaches identified here should be considered as a potential framework by others when evaluating the exposure assessment component of epidemiological studies for systematic reviews.

The Associations Between Workplace Noise, Ototoxic Chemicals, and Tinnitus.

OBJECTIVE: To investigate the occupational risk factors associated with tinnitus in the Australian working population. DESIGN: The research was conducted using data collected from the Australian Workplace Exposure Survey-Hearing, a national cross-sectional study of 4970 workers conducted in 2016 to 2017. Workers were asked if they experienced tinnitus and if they answered affirmatively, they were asked about the frequency and length of the presentations. Based on their answers, each worker was categorized as having no tinnitus or any tinnitus, with an additional group of workers with any tinnitus subcategorized as having constant tinnitus. Exposure assessment was conducted using an automated expert assessment method. Exposures included daily noise (L Aeq,8h ), hand-arm vibration (A(8)), impulse noise, smoking status, styrene, trichloroethylene, toluene, n-hexane, p-xylene, ethylbenzene, lead, and carbon monoxide. Univariate and multivariate logistic regression models were used to examine the associations between workplace exposures and tinnitus. RESULTS: Workers with an estimated noise exposure above the workplace limit (L Aeq,8h > 85 dBA) had 1.73 (95% confidence interval [CI]: 1.42 to 2.11) increased odds of any tinnitus and 2.15 (95% CI: 1.60 to 2.89) odds of constant tinnitus. The odds of workers having any tinnitus increased with increasing noise exposure levels in a dose-response relationship that strengthened when considering only those with constant tinnitus. In the fully adjusted model, statistically significant associations were seen for lead exposure with both any and constant tinnitus, toluene exposure with constant tinnitus, and carbon monoxide exposure with any tinnitus. CONCLUSIONS: These results suggest that, in addition to workplace noise, occupational exposures to lead, toluene, and carbon monoxide are associated with tinnitus.

The association between breast arterial calcification and atherosclerotic cardiovascular disease in an Australian population-based breast cancer case-control study.

PURPOSE: Atherosclerotic cardiovascular disease (ASCVD) is a major cause of morbidity and mortality. Breast arterial calcification (BAC) on mammograms is not associated with breast cancer risk. However, there is increasing evidence supporting its association with cardiovascular disease (CVD). This study examines the association between BAC and ASCVD and their risk factors within an Australian population-based breast cancer study. MATERIALS AND METHODS: Data from the controls who participated in the breast cancer environment and employment study (BCEES) were linked with the Western Australian Department of Health Hospital Morbidity database and Mortality Registry to obtain ASCVD outcomes and related risk factor data. Mammograms from participants with no prior history of ASCVD were assessed for BAC by a radiologist. Cox proportional hazards regression was used to examine the association between BAC and later occurrence of an ASCVD event. Logistic regression was used to investigate the factors associated with BAC. RESULTS: A total of 1020 women with a mean age of 60 (sd = 7.0 years) were included and BAC found in 184 (18.0%). Eighty (7.8%) of the 1020 participants developed ASCVD, with an average time to event of 6.2 years (sd = 4.6) from baseline. In univariate analysis, participants with BAC were more likely to have an ASCVD event (HR = 1.96 95% CI 1.29-2.99). However, after adjusting for other risk factors, this association attenuated (HR = 1.37 95% CI 0.88-2.14). Increasing age (OR = 1.15, 95% CI 1.12-1.19) and parity (pLRT < 0.001) were associated with BAC. CONCLUSION: BAC is associated with increased ASCVD risk, but this is not independent of cardiovascular risk factors.

The prevalence of tinnitus in the Australian working population.

OBJECTIVES: To estimate the prevalence of tinnitus in Australian working people; to identify occupational and demographic factors associated with tinnitus. DESIGN: Cross-sectional national telephone survey of self-reported frequency and duration of tinnitus. SETTING, PARTICIPANTS: Australian Workplace Exposure Survey (AWES) - Hearing; 4970 currently employed people aged 18-64 years, recruited by random digit dialling, representative by sex of the workforce population, 7 June 2016 - 20 March 2017. MAIN OUTCOME MEASURES: Prevalence of occasional, intermittent, and constant tinnitus, and of any tinnitus, by occupational group, sex, and other demographic characteristics; estimated numbers of working people with constant or any tinnitus, by occupational group and sex. RESULTS: Of 4970 respondents, 1317 reported experiencing tinnitus (26.5%): 713 people had occasional tinnitus (14.3%), 259 intermittent tinnitus (5.2%), and 345 constant tinnitus (6.9%). The sample prevalence of constant tinnitus was greater among men (7.5%; 95% CI, 6.2-8.7%) than women (3.3%; 95% CI, 2.3-4.3%), and was higher in older age groups. After rake weighting our survey responses, we estimated that 2.4 million workers (24.8%; 95% CI, 23.2-26.4%) experience tinnitus, including 529 343 with constant tinnitus (5.5%; 95% CI, 4.6-6.3%). The estimated prevalence of constant tinnitus was highest for automotive workers (16.7%; 95% CI, 9.5-23.8%), drivers (13.0%; 95% CI, 7.3-18.6%), farmers (12.1%; 95% CI, 5.9-18.4%), and workers in other trades (10.4%; 95% CI, 4.6-16.2%). CONCLUSIONS: The prevalence of tinnitus in the Australian workforce is high, particularly in certain occupations. Workplace practices and conditions that increase the risk of tinnitus should be examined, and targeted workplace prevention strategies developed.

Herbicide use in farming and other jobs in relation to non-Hodgkin's lymphoma (NHL) risk.

OBJECTIVES: Given mixed evidence for carcinogenicity of current-use herbicides, we studied the relationship between occupational herbicide use and risk of non-Hodgkin's lymphoma (NHL) in a large, pooled study. METHODS: We pooled data from 10 case-control studies participating in the International Lymphoma Epidemiology Consortium, including 9229 cases and 9626 controls from North America, the European Union and Australia. Herbicide use was coded from self-report or by expert assessment in the individual studies, for herbicide groups (eg, phenoxy herbicides) and active ingredients (eg, 2,4-dichlorophenoxyacetic acid (2,4-D), glyphosate). The association between each herbicide and NHL risk was estimated using logistic regression to produce ORs and 95% CIs, with adjustment for sociodemographic factors, farming and other pesticides. RESULTS: We found no substantial association of all NHL risk with ever-use of any herbicide (OR=1.10, 95% CI: 0.94 to 1.29), nor with herbicide groups or active ingredients. Elevations in risk were observed for NHL subtypes with longer duration of phenoxy herbicide use, such as for any phenoxy herbicide with multiple myeloma (>25.5 years, OR=1.78, 95% CI: 0.74 to 4.27), 2,4-D with diffuse large B-cell lymphoma (>25.5 years, OR=1.47, 95% CI: 0.67 to 3.21) and other (non-2,4-D) phenoxy herbicides with T-cell lymphoma (>6 years, lagged 10 years, OR=3.24, 95% CI: 1.03 to 10.2). An association between glyphosate and follicular lymphoma (lagged 10 years: OR=1.48, 95% CI: 0.98 to 2.25) was fairly consistent across analyses. CONCLUSIONS: Most of the herbicides examined were not associated with NHL risk. However, associations of phenoxy herbicides and glyphosate with particular NHL subtypes underscore the importance of estimating subtype-specific risks.

Comparison of agreement in asthmagen exposure assessments between rule-based automatic algorithms and a job exposure matrix in healthcare workers in Australia and Bhutan.

BACKGROUND: Assessment of occupational exposures is an integral component of population-based studies investigating the epidemiology of occupational diseases. However, all the available methods for exposure assessment have been developed, tested and used in high-income countries. Except for a few studies examining pesticide exposures, there is limited research on whether these methods are appropriate for assessing exposure in LMICs. The aim of this study is to compare a task-specific algorithm-based method (OccIDEAS) to a job-specific matrix method (OAsJEM) in the assessment of asthmagen exposures among healthcare workers in a high-income country and a low- and middle- income country (LMIC) to determine an appropriate assessment method for use in LMICs for future research. METHODS: Data were obtained from a national cross-sectional survey of occupational asthmagens exposure in Australia and a cross-sectional survey of occupational chemical exposure among Bhutanese healthcare workers. Exposure was assessed using OccIDEAS and the OAsJEM. Prevalence of exposure to asthmagens and inter-rater agreement were calculated. RESULTS: In Australia, the prevalence was higher for a majority of agents when assessed by OccIDEAS than by the OAsJEM (13 versus 3). OccIDEAS identified exposures to a greater number of agents (16 versus 7). The agreement as indicated by κ (Cohen's Kappa coefficient) for six of the seven agents assessed was poor to fair (0.02 to 0.37). In Bhutan, the prevalence of exposure assessed by OccIDEAS was higher for four of the seven agents and κ was poor for all the four agents assessed (-0.06 to 0.13). The OAsJEM overestimated exposures to high-level disinfectants by assigning exposures to all participants from 10 (Bhutan) and 12 (Australia) ISCO-88 codes; whereas OccIDEAS assigned exposures to varying proportions of participants from these ISCO-codes. CONCLUSION: There was poor to fair agreement in the assessment of asthmagen exposure in healthcare workers between the two methods. The OAsJEM overestimated the prevalence of certain exposures. As compared to the OAsJEM, OccIDEAS appeared to be more appropriate for evaluating cross-country exposures to asthmagens in healthcare workers due to its inherent quality of assessing task-based determinants and its versatility in being adaptable for use in different countries with different exposure circumstances.

Association of germline genetic variants with breast cancer-specific survival in patient subgroups defined by clinic-pathological variables related to tumor biology and type of systemic treatment.

BACKGROUND: Given the high heterogeneity among breast tumors, associations between common germline genetic variants and survival that may exist within specific subgroups could go undetected in an unstratified set of breast cancer patients. METHODS: We performed genome-wide association analyses within 15 subgroups of breast cancer patients based on prognostic factors, including hormone receptors, tumor grade, age, and type of systemic treatment. Analyses were based on 91,686 female patients of European ancestry from the Breast Cancer Association Consortium, including 7531 breast cancer-specific deaths over a median follow-up of 8.1 years. Cox regression was used to assess associations of common germline variants with 15-year and 5-year breast cancer-specific survival. We assessed the probability of these associations being true positives via the Bayesian false discovery probability (BFDP < 0.15). RESULTS: Evidence of associations with breast cancer-specific survival was observed in three patient subgroups, with variant rs5934618 in patients with grade 3 tumors (15-year-hazard ratio (HR) [95% confidence interval (CI)] 1.32 [1.20, 1.45], P = 1.4E-08, BFDP = 0.01, per G allele); variant rs4679741 in patients with ER-positive tumors treated with endocrine therapy (15-year-HR [95% CI] 1.18 [1.11, 1.26], P = 1.6E-07, BFDP = 0.09, per G allele); variants rs1106333 (15-year-HR [95% CI] 1.68 [1.39,2.03], P = 5.6E-08, BFDP = 0.12, per A allele) and rs78754389 (5-year-HR [95% CI] 1.79 [1.46,2.20], P = 1.7E-08, BFDP = 0.07, per A allele), in patients with ER-negative tumors treated with chemotherapy. CONCLUSIONS: We found evidence of four loci associated with breast cancer-specific survival within three patient subgroups. There was limited evidence for the existence of associations in other patient subgroups. However, the power for many subgroups is limited due to the low number of events. Even so, our results suggest that the impact of common germline genetic variants on breast cancer-specific survival might be limited.

Occupational insecticide exposure and risk of non-Hodgkin lymphoma: A pooled case-control study from the InterLymph Consortium.

Evidence for the human health effects of pesticides is needed to inform risk assessment. We studied the relationship between occupational insecticide use and risk of non-Hodgkin lymphoma (NHL) by pooling data from nine case-control studies participating in the InterLymph Consortium, including 7909 cases and 8644 controls from North America, the European Union and Australia. Insecticide use was coded using self-report or expert assessment, for insecticide groups (eg, organophosphates, pyrethroids) and active ingredients (eg, malathion, permethrin). Associations with insecticides were estimated using logistic regression to produce odds ratios (ORs) and 95% confidence intervals (CI) for all NHL and NHL subtypes, with adjustment for study site, demographic factors and use of other pesticides. Occupational insecticide use, overall, was not associated with risk of NHL. Use of organophosphate insecticides was associated with increased risk of all NHL and the subtype follicular lymphoma, and an association was found with diazinon, in particular (ever use: OR = 2.05, 95%CI: 1.24-3.37). The carbamate insecticide, carbaryl, was associated with risk of all NHL, and the strongest associations were found with T-cell NHL for ever-use (OR = 2.44, 95%CI: 1.13-5.28) and longer duration (>8 years vs never: OR = 2.90, 95%CI: 1.02-8.25). There was no association of NHL with other broad groups of insecticides, including organochlorines and pyrethroids, and some inverse associations were estimated in relation to historical DDT use. Our findings contribute to the totality of evidence available to help inform risk decisions by public health and regulatory agencies of importance given continued, widespread use of organophosphate and carbamate insecticides.

Mendelian randomisation study of smoking exposure in relation to breast cancer risk.

BACKGROUND: Despite a modest association between tobacco smoking and breast cancer risk reported by recent epidemiological studies, it is still equivocal whether smoking is causally related to breast cancer risk. METHODS: We applied Mendelian randomisation (MR) to evaluate a potential causal effect of cigarette smoking on breast cancer risk. Both individual-level data as well as summary statistics for 164 single-nucleotide polymorphisms (SNPs) reported in genome-wide association studies of lifetime smoking index (LSI) or cigarette per day (CPD) were used to obtain MR effect estimates. Data from 108,420 invasive breast cancer cases and 87,681 controls were used for the LSI analysis and for the CPD analysis conducted among ever-smokers from 26,147 cancer cases and 26,072 controls. Sensitivity analyses were conducted to address pleiotropy. RESULTS: Genetically predicted LSI was associated with increased breast cancer risk (OR 1.18 per SD, 95% CI: 1.07-1.30, P = 0.11 × 10-2), but there was no evidence of association for genetically predicted CPD (OR 1.02, 95% CI: 0.78-1.19, P = 0.85). The sensitivity analyses yielded similar results and showed no strong evidence of pleiotropic effect. CONCLUSION: Our MR study provides supportive evidence for a potential causal association with breast cancer risk for lifetime smoking exposure but not cigarettes per day among smokers.

A systematic review and meta-analysis of occupational exposures and risk of follicular lymphoma.

BACKGROUND: The etiology of follicular lymphoma (FL), a common non-Hodgkin lymphoma subtype, is largely unknown. OBJECTIVE: We performed a systematic review and meta-analysis of observational studies examining the relationship between occupational exposures and FL risk. METHODS: We searched Ovid MEDLINE, Ovid EMBASE, and Web of Science for eligible observational studies examining job titles or occupational exposures prior to January 1, 2020. We performed a narrative synthesis and used random-effects models to generate meta-estimates of relative risk (RR) with 95% confidence intervals (95%CI) for exposures reported by three or more studies. RESULTS: Fifty-eight studies were eligible. Ten cohort and 37 case-control studies quantified FL risk in relation to any exposure to one or more occupational groups or agents. Eight cohort and 19 case-control studies examined dose-response relationships. We found evidence of a positive association with increasing plasma concentration of dichlorodiphenyldichloroethylene (DDE; meta-RR = 1.51, 95%CI = 0.99, 2.31; I2 = 0.0%) and polychlorinated biphenyls (PCBs; meta-RR = 1.47, 95%CI = 0.97, 2.24; I2 = 8.6%). We observed a positive association with exposure to any solvent (meta-RR = 1.16, 95%CI = 1.00, 1.34; I2 = 0.0%) and chlorinated solvents (meta-RR = 1.35, 95%CI = 1.09, 1.68; I2 = 0.0%). Single studies reported a significant positive dose-response association for exposure to any pesticide, hexachlorobenzene, any organophosphate, diazinon, metolachlor, carbaryl, lindane, trichloroethylene, oils/greases, and extremely low-frequency magnetic fields. Job title-only analyses suggested increased risk for medical doctors and spray painters, and decreased risk for bakers and teachers. Overall, studies demonstrated low risk of bias, but most studies examined small numbers of exposed cases. CONCLUSIONS: Current evidence indicates a positive association between FL and occupational exposure to DDE, PCBs, any solvent and chlorinated solvents. Our findings may help guide policies and practices on the safe use of solvents and inform models of lymphomagenesis. Future studies with larger sample sizes and comprehensive quantitative exposure measures may elucidate other avoidable carcinogenic exposures.

Contribution of Occupational Health to multidisciplinary team work for COVID-19 prevention and management.

INTRODUCTION: The SARS-CoV-2/Covid-19 pandemic is a challenge for public health and occupational medicine and developing prevention and protection strategies needs expertise from many disciplines. To make prevention successful, individuals have to be motivated to participate and, in turn, motivation depends on understanding how and why prevention measures are implemented. We present a structured approach (the Cycle of prevention) which involves different stakeholders and perspectives to develop, and monitor, prevention strategies in transparent and effective ways.

No association between night shiftwork and mammographic density.

BACKGROUND: Increased mammographic density is one of the strongest risk factors for breast cancer. Night shiftwork and its related factors, which include light at night, phase shift and sleep disruption, are believed to increase breast cancer risk however, their effects on mammographic density have barely been studied. METHODS: This study included 1821 women enrolled in the Breast Cancer Environment and Employment Study between 2009 and 2011. Mammographic density was measured using the Cumulus software program. The association of night shiftwork factors with square root transformed absolute dense area (DA) and percentage dense area (PDA) were modelled using linear regression adjusted for confounders. RESULTS: Ever doing graveyard shiftwork (between 24:00 and 05:00 hours) was not associated with PDA (ß=-0.10; 95% CI -0.27 to 0.08)) and DA (ß=-0.12; 95% CI -0.33 to 0.09)). No association was found between night shiftwork related factors (light at night, phase shift and sleep disturbance) with PDA or DA. CONCLUSIONS: Shiftwork and its related factors are not associated with mammographic density. Using high-quality, comprehensive shiftwork data from a large population-based breast cancer case-control study, this study suggests that mammographic density does not play a role in the relationship between shiftwork and breast cancer risk.

Predictive value of non-specific bronchial challenge testing for respiratory symptoms and lung function in aluminium smelter workers.

OBJECTIVE: To assess the predictive value of bronchial hyper-responsiveness (BHR) for the subsequent development of respiratory symptoms, airflow limitation and decline in lung function among aluminium smelter workers. METHODS: An inception cohort study of new employees at two Australian aluminium smelters was conducted. Participants completed a modified British Medical Research Council respiratory questionnaire, spirometry and a methacholine bronchial challenge test at baseline and at annual follow-up reviews. BHR was defined as PD20 ≤4000 µg. Poisson and mixed effects models were fitted to respiratory symptoms and lung function (forced expiratory volume in 1 s (FEV1) and FEV1/forced vital capacity (FVC)). RESULTS: Baseline interview and lung function testing were completed by 278 workers, who were followed for a median of 4 years. BHR at baseline, present in 82 workers, was not associated with incident wheeze risk ratio (RR)=1.07 (95% CI 0.74 to 1.55) and cough RR=0.78 (95% CI 0.45, 1.35), but there was some increased risk of chest tightness RR=1.40 (95% CI 0.99, 1.98) after adjustment for age, sex, smoking and atopy. BHR at baseline was associated with lower FEV1 and FVC, although the rate of annual decline in FEV1 or FVC was similar between those with or without BHR. The specificity of BHR was 77% for wheeze, 70% for cough and 77% for chest tightness, but the sensitivity was poor, at 33%, 24% and 39%, respectively. CONCLUSION: Methacholine challenge testing at entry to employment was not sufficiently predictive of later adverse respiratory outcomes, and notwithstanding the study limitations is unlikely to be a useful pre-employment or preplacement screening test in the aluminium smelting industry.

Occupational exposures to hazardous chemicals and agents among healthcare workers in Bhutan.

BACKGROUND: Occupational exposures to hazardous chemicals among healthcare workers can result in long-term adverse health outcomes. Research on such exposures from low- and middle-income countries is limited. The aim of this study was to estimate the prevalence of exposures to a range of chemicals used in healthcare settings among Bhutanese healthcare workers. METHODS: A cross-sectional study was conducted among healthcare workers (n = 370) working in three hospitals in the western region of Bhutan. Demographic and occupational information was collected, and exposures to asthmagens, carcinogens, ototoxic and other agents were assessed using a web-based tool. The prevalence of exposure to these chemicals was calculated and the circumstances resulting in such exposures were examined. RESULTS: The prevalence of exposure to one or more asthmagen, carcinogen, and ototoxic agent was 98.7%, 28.1%, and 7.6%, respectively; and was 6.2% for anesthetic gases and 2.2% for antineoplastic drugs. The most common exposures were to latex, and cleaning and disinfecting agents in the asthmagens group; formaldehyde in the carcinogens group; and p-xylene among ototoxic agents. The circumstances resulting in exposures were using latex gloves, using bleach and chlorhexidine for cleaning, using formaldehyde as a disinfectant and in the laboratory, and using p-xylene in the laboratory. CONCLUSIONS: The results indicate that a large proportion of Bhutanese healthcare workers are occupationally exposed to chemicals linked to chronic diseases, with exposure prevalence higher than in high-income countries. The study provides information that can be used to formulate policies and to implement control measures to protect healthcare workers.

Does exposure to workplace hazards cluster by occupational or sociodemographic characteristics? An analysis of foreign-born workers in Australia.

BACKGROUND: Disparities in exposure to occupational hazards may be linked to social position as well as the type of job a person holds. This study aimed to describe the prevalence of exposure to workplace hazards among three migrant worker groups and to assess whether social disparities in exposure for these groups remain after adjusting for occupational characteristics. METHODS: Data were collected in 2017/2018 from 1630 Australian workers born in New Zealand, India, and the Philippines. Weighted estimated prevalence of exposure to 10 carcinogens and four psychosocial hazards (discrimination, job strain, vulnerability, and insecurity) was calculated for sociodemographics and occupation. Regression estimated the likelihood of exposure by sociodemographics after adjustment for occupational characteristics. RESULTS: Exposure to workplace hazards ranged from 11.7% (discrimination) to 61.2% (exposed to at least one carcinogen). Compared with workers born in India, New Zealand born workers were over twice as likely to be exposed to diesel engine exhaust (adjusted odds ratio [aOR] = 2.60) and 60% more likely to be exposed to at least one carcinogen (aOR = 1.60) but less likely to be exposed to any psychosocial hazard. Social disparities by country of birth, sex, age, education, and number of years in Australia, as well as company size, employment type, and hours, worked remained associated with greater likelihood of reporting one or more workplace hazards after adjusting for occupational characteristics. CONCLUSION: Examining sociodemographic as well as occupational characteristics helps to clarify groups most likely to be exposed to workplace hazards who can be hidden when examining occupational characteristics alone.

The estimated prevalence of exposure to carcinogens, asthmagens, and ototoxic agents among healthcare workers in Australia.

BACKGROUND: Healthcare workers are occupationally exposed to various hazardous chemicals and agents that can potentially result in long-term adverse health effects. These exposures have not been comprehensively examined at a population level. The aim of this study was to examine occupational exposures to a wide range of asthmagens, carcinogens, and ototoxic agents among healthcare workers in Australia. METHODS: Data were collected as part of the Australian Work Exposures Studies, which were computer-assisted telephone surveys conducted in 2011, 2014, and 2016 to assess the prevalence of occupational exposures to carcinogens, asthmagens, and ototoxic agents, respectively, among Australian workers. Using data on healthcare workers, the prevalence of exposures to these agents was calculated and associations of demographic variables and occupation groups with exposure status were examined. RESULTS: The prevalence of exposure to at least one asthmagen, carcinogen, and ototoxic agent was 92.3%, 50.7%, and 44.6%, respectively. The most common exposures were to (a) cleaning and sterilizing agents in the asthmagen group; (b) shift work in the carcinogen group; and (c) toluene and p-xylene among ototoxic agents. Exposure varied by occupation, with exposure to carcinogens and ototoxic agents highest among personal carers and exposure to carcinogens most likely among nursing professionals and health and welfare support workers. CONCLUSION: The results demonstrate that a substantial proportion of Australian healthcare workers are occupationally exposed to asthmagens, carcinogens, and ototoxic agents. These exposures are more common among certain occupational groups. The information provided by this study will be useful in prioritizing and implementing control strategies.

Respiratory outcomes among refinery workers exposed to inspirable alumina dust: A longitudinal study in Western Australia.

BACKGROUND: Information is scarce about the occupational health effects of exposure to alumina dust. This study examines the respiratory effects of inspirable alumina dust exposure in alumina refineries. METHODS: An inception cohort study at three alumina refineries in Western Australia recruited 416 participants (351 males, 65 females) between 1995 and 2000 who were followed up annually until 2008 or until exit from study. At each health interview a respiratory questionnaire and lung function test was undertaken, measuring forced expiratory volume in one second (FEV1 ) and forced vital capacity (FVC). Participants provided job histories which were combined with air monitoring data to calculate cumulative exposure to inspirable alumina dust (mg/m3 -years). Generalized estimating equations with Poisson distribution and mixed effects models were used to examine the effects of alumina exposure. RESULTS: The number of exposed participants was relatively small (n = 82, 19.7%). There was no association between alumina dust exposure and prevalence of cough, wheeze or rhinitis. No associations were found between measures of lung function and tertiles of alumina exposure in the first two follow-ups, or the whole follow-up period, though there was a suggestive dose-response trend across exposed groups for decline in absolute FEV1 (p for trend = .06). For mean annual change in FEV1 and FVC based on the first three follow-ups it was not possible to rule out an effect above a threshold level of exposure. CONCLUSION: There is no evidence of an association between exposure to alumina and the reporting of respiratory symptoms but some evidence for an effect on lung function.

Lifetime recreational physical activity and the risk of prostate cancer.

PURPOSE: Research on the association between physical activity and the risk of prostate cancer is inconsistent. The aim of this study was to investigate whether the timing, intensity, and type of recreational physical activity influence prostate cancer risk. METHODS: A population-based case-control study was conducted in Western Australia in 2001-2002. Data were collected on lifetime recreational physical activity from a self-reported questionnaire. The estimated effects of recreational physical activity on prostate cancer risk were analyzed using logistic regression, adjusting for demographic and lifestyle factors. This analysis included 569 incident cases and 443 controls. RESULTS: There was a significant, inverse dose-response relationship between vigorous-intensity recreational physical activity between the ages 19 and 34 years and the risk of prostate cancer (pTrend = 0.013). Participants in the most active quartile of vigorous-intensity physical activity in this age period had a 33% lower risk of prostate cancer than participants in the least active quartile (Adjusted Odds Ratio = 0.67, 95% confidence interval = 0.45-1.01). Moderate-intensity recreational physical activity was not associated with the risk of prostate cancer. Recreational physical activity performed over the lifetime showed no association with prostate cancer risk. Weight training performed from early adulthood onwards showed a non-significant but consistent inverse association with prostate cancer risk. There was no strong evidence that physical activity was differentially associated with the risks of low-grade and medium-to-high grade prostate cancers. CONCLUSIONS: A high level of vigorous recreational physical activity in early adulthood may be required to reduce the risk of prostate cancer.

Exposure to noise and ototoxic chemicals in the Australian workforce.

OBJECTIVE: To determine the current prevalence of exposure to workplace noise and ototoxic chemicals, including co-exposures. METHOD: A cross-sectional telephone survey of nearly 5000 Australian workers was conducted using the web-based application, OccIDEAS. Participants were asked about workplace tasks they performed and predefined algorithms automatically assessed worker's likelihood of exposure to 10 known ototoxic chemicals as well as estimated their full shift noise exposure level (LAeq,8h) of their most recent working day. Results were extrapolated to represent the Australian working population using a raked weighting technique. RESULTS: In the Australian workforce, 19.5% of men and 2.8% of women exceeded the recommended full shift noise limit of 85 dBA during their last working day. Men were more likely to be exposed to noise if they were younger, had trade qualifications and did not live in a major city. Men were more likely exposed to workplace ototoxic chemicals (57.3%) than women (25.3%). Over 80% of workers who exceeded the full shift noise limit were also exposed to at least one ototoxic chemical in their workplace. CONCLUSION: The results demonstrate that exposures to hazardous noise and ototoxic chemicals are widespread in Australian workplaces and co-exposure is common. Occupational exposure occurs predominantly for men and could explain some of the discrepancies in hearing loss prevalence between genders.