Workers in Australian prebake aluminium smelters: update on risk of mortality and cancer incidence in the Healthwise cohort.

OBJECTIVES: To investigate mortality and the rates of incident cancer among a cohort of aluminium industry workers. METHODS: Among 4507 male employees who worked in either of two Australian prebake smelters for at least 3 months, data linkage was undertaken with the Australian National Death Index and Australian Cancer Database. Standardised Mortality Ratios (SMRs) and Standardised Incidence Rates (SIRs) were estimated for the whole cohort and for: production; maintenance and office workers. SMRs and SIRs were calculated by time since first employment. RESULTS: Among production workers, there was an excess risk of mortality from mesothelioma (SMR 2.8, 95% CI 1.3 to 5.2), lung (SMR 1.4, 95% CI 1.0 to 1.8), prostate (SMR 1.9, 95% CI 1.3 to 2.7) and liver cancer (SMR 2.0, 95% CI 1.1 to 3.4) and the SIR was also increased for overall respiratory cancers, specifically lung cancers. An excess risk of death from stomach cancer (SMR 2.9, 95% CI 1.2 to 6.1) and Alzheimer's disease (SMR 3.4, 95% CI 1.1 to 7.9) was seen among maintenance workers. The overall risk of death was similar to that of the Australian general population, as was mortality from cancers overall and non-malignant respiratory disease. CONCLUSIONS: No excess risk of death from bladder cancer or non-malignant respiratory disease was found. Excess lung cancer mortality and incidence may be explained by smoking and excess mortality from mesothelioma may be explained by asbestos exposure. An excess risk of mortality from liver and prostate cancer has been shown in production workers and requires further investigation.

Incidence and mortality from malignant mesothelioma 1982-2020 and relationship with asbestos exposure: the Australian Mesothelioma Registry.

OBJECTIVES: Malignant mesothelioma is an uncommon cancer associated with asbestos exposure, predominantly occupational. Asbestos has been banned in Australia since 2003 but mesothelioma has a long latency and incident cases continue to present. The Australian Mesothelioma Registry was incepted to collect systematic data about incidence and mortality alongside asbestos exposure. METHODS: Benefiting from the Australian national system of cancer notification, all incident cases of mesothelioma in all states and territories are fast-tracked and notified regularly. Notified patients are contacted asking for consent to collect exposure information, initially by postal questionnaire and subsequently by telephone interview. Age-standardised annual incidence rates and mortality rates were calculated. Asbestos exposure was categorised as occupational, non-occupational, neither or, both; and as low, or high, probability of exposure. RESULTS: Mesothelioma incidence appears to have peaked. The age-standardised incidence rates have declined steadily since the early 2000s (peaking in males at 5.9/100 000 and in all-persons at 3.2/100 000), driven by rates in males, who comprise the majority of diagnosed cases. Rates in women have remained fairly stable since that time. Age-standardised mortality rates have followed similar trends. Mesothelioma remains the most common in those aged over 80 years. Nearly all (94%) cases were linked with asbestos exposure (78% occupational in men; 6.8% in women). CONCLUSIONS: With effective control of occupational asbestos use, the decline in age-standardised incidence and death rates has occurred. Incidence rates among women, in whom occupational asbestos exposure is rarely detectable, remain unchanged, pointing to the role of household and /or environmental asbestos exposure.

Workers' compensation claims for COVID-19 among workers in healthcare and other industries during 2020-2022, Victoria, Australia.

OBJECTIVE: To identify and characterise COVID-19 workers' compensation claims in healthcare and other industries during the pandemic in Victoria, Australia. METHODS: We used workers' compensation claims identified as COVID-19 infection related from 1 January 2020 to 31 July 2022 to compare COVID-19 infection claims and rates of claims by industry and occupation, and in relation to Victorian COVID-19 epidemiology. A Cox proportional hazards model assessed risk factors for extended claim duration. RESULTS: Of the 3313 direct and indirect COVID-19-related claims identified, 1492 (45.0%) were classified as direct COVID-19 infection accepted time-loss claims and were included in analyses. More than half (52.9%) of COVID-19 infection claims were made by healthcare and social assistance industry workers, with claims for this group peaking in July-October 2020. The overall rate of claims was greater in the healthcare and social assistance industry compared with all other industries (16.9 vs 2.4 per 10 000 employed persons) but industry-specific rates were highest in public administration and safety (23.0 per 10 000 employed persons). Workers in healthcare and social assistance were at increased risk of longer incapacity duration (median 26 days, IQR 16-61 days) than in other industries (median 17 days, IQR 11-39.5 days). CONCLUSIONS: COVID-19 infection claims differed by industry, occupational group, severity and timing and changes coincided with different stages of the COVID-19 pandemic. Occupational surveillance for COVID-19 cases is important and monitoring of worker's compensation claims and incapacity duration can contribute to understanding the impacts of COVID-19 on work absence.

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.

Mortality and cancer incidence among female Australian firefighters.

OBJECTIVES: To investigate the mortality and cancer incidence of female firefighters, a group where there are limited published findings. METHODS: Participating fire agencies supplied records of individual firefighters including the number and type of incidents attended. The cohort was linked to the Australian National Death Index and Australian Cancer Database. Standardised mortality ratios and standardised cancer incidence ratios were calculated separately for paid and volunteer firefighters. Volunteer firefighters were grouped into tertiles by the duration of service and by a number of incidents attended and relative mortality ratios and relative incidence ratios calculated. RESULTS: For volunteer firefighters (n=37 962), the overall risk of mortality and risk from all major causes of death were reduced when compared with the general population whether or not they had ever attended incidents. Volunteer firefighters had a similar cancer incidence when compared with the general population for most major cancer categories. Female volunteer firefighters have usually attended few fires. Of those who had turned out to incidents, only one-third had attended more than 12 fires about half the number for male volunteers. Mortality and cancer incidence for paid female firefighters (n=1682) were similar to the general population but the numbers were small and so power was limited. CONCLUSIONS: Female volunteer firefighters have a cancer incidence similar to the general population but a reduced risk of mortality which is likely to be a result of a 'healthy volunteer' effect.Most of the paid female firefighters were relatively recent recruits and it will be important to monitor the health of this group as more women are recruited to front-line firefighting roles.

Immunological effects among workers who handle engineered nanoparticles.

OBJECTIVE: To determine whether exposure of workers handling engineered nanoparticles (ENPs) may result in increased inflammation and changes in lung function. METHODS: A prospective panel study compared changes in several markers of inflammation for ENP handling and non-ENP handling control workers. Nanoparticle exposure was measured during ENP handling and for controls. Lung function, fraction of exhaled nitric oxide (FeNO), C-reactive protein (CRP), blood cell counts and several serum cytokines were measured at baseline, at the end of the shift and at the end of the working week. RESULTS: Nanoparticle exposure was not higher when ENPs were being handled; nanoparticle counts were higher in offices and in ambient air than in laboratories. There were no differences at baseline in lung function, FeNO, haemoglobin, platelet, white cell counts or CRP levels between those who handled nanoparticles and those who did not, with or without asthmatic participants. There were statistically significant increases in sCD40 and sTNFR2 over the working day for those who handled ENPs. The changes were larger and statistically significant over the working week and sCD62P also showed a statistically significant difference. The changes were slightly smaller and less likely to be statistically significant for atopic than for non-atopic participants. CONCLUSIONS: Even at low ENP exposure, increases in three cytokines were significant over the week for those who handled nanoparticles, compared with those who did not. However, exposure to low and transient levels of nanoparticles was insufficient, to trigger measurable changes in spirometry, FeNO, CRP or blood cell counts.

Alcohol use and substance use disorders in Gulf War, Afghanistan, and Iraq War veterans compared with nondeployed military personnel.

Although recent veterans have been found to be at increased risk of psychiatric disorders, limited research has focused on alcohol or substance use disorders. This systematic review and meta-analysis examined whether alcohol or substance use disorders were more common in Gulf War, Afghanistan, and Iraq War veterans compared with military comparison groups nondeployed to the corresponding conflict, including never deployed personnel. Literature was searched (1990-2014) in multiple electronic databases. Studies were assessed for eligibility and quality, including risk of bias. Eighteen studies (1997-2014) met inclusion criteria. Pooled analysis based on a random-effects model yielded a summary odds ratio of 1.33 (95% confidence interval (CI): 1.22, 1.46) for alcohol (7 studies) and 2.13 (95% CI: 0.96, 4.72) for substance use (3 studies) disorders among Gulf War veterans, as well as 1.36 (95% CI: 1.11, 1.66) for alcohol (7 studies) and 1.14 (95% CI: 1.04, 1.25) for substance use (4 studies) disorders among Iraq/Afghanistan veterans; meta-regressions found no statistically significant association between theater of war and alcohol use or substance use disorders. Our findings indicate that Gulf and Iraq/Afghanistan war veterans are at higher alcohol use disorder risk than nondeployed veterans, but further studies with increased power are needed to assess substance use disorder risk in Gulf War veteran populations.

Occupational injury risk among ambulance officers and paramedics compared with other healthcare workers in Victoria, Australia: analysis of workers' compensation claims from 2003 to 2012.

OBJECTIVE: To investigate occupational risk of musculoskeletal (MSK) and mental injury among ambulance officers and paramedics, and compare with nurse professionals, social and welfare professionals, and carers and aides in Victoria, Australia, using workers' compensation (WC) claims statistics. METHODS: Data were retrieved from the Victorian Compensation Research Database (CRD). Analysis was restricted to claims received between 1 July 2003 and 30 June 2012. WC claim rates were calculated using labour force statistics, and expressed per 1000 full-time equivalent workers. Adjusted HRs with 95% CIs for injury risk were estimated using multivariable regression modelling. RESULTS: Ambulance officers and paramedics had an upward trend in WC claim rates for all injuries and the highest rates for MSK and mental injury, in comparison with other healthcare workers during the study period. In the 2009-2012 time period, ambulance officers and paramedics' risk of lower back MSK and mental injury was approximately 13 times higher than nurse professionals, HRs 57.6 vs 4.4 and 17.77 vs 1.29, respectively. Social and welfare professionals had the second highest risk of mental injury, which was up to threefold greater than in nurses. Carers and aides and nurse professionals had similar HRs overall for all injury categories. CONCLUSIONS: Differential patterns of MSK and mental injury exist among healthcare occupational groups in Victoria, Australia. Given the significant findings, especially the high risks among ambulance personnel, future research should focus on the circumstances of injury to improve understanding and inform prevention programmes.

Longitudinal analysis of respiratory outcomes among bauxite exposed workers in Western Australia.

INTRODUCTION: Occupational exposure to bauxite is common in the aluminium industry but little is known about the associated health effects. This study investigates respiratory health in relation to respirable bauxite dust exposure longitudinally over a 13 year period. METHODS: An inception cohort study recruited 91 male bauxite miners and 363 male alumina refinery workers. Annual measurements of respiratory symptoms and lung function were made. Cumulative exposure to bauxite was derived from job histories and air monitoring data. Mixed-effects modeling was used. RESULTS: No associations were found between cumulative bauxite exposure and respiratory symptoms or lung function. However, when analysis was restricted to the first three rounds, FEV1 was significantly lower in all exposure groups than in those unexposed but with no significant trend. CONCLUSION: Increasing exposure to bauxite dust in the aluminum industry was not associated with respiratory symptoms or consistent decrements in lung function.

Outdoor air pollution as a trigger for out-of-hospital cardiac arrests.

BACKGROUND: Epidemiologic studies have reported associations between fine particulate air pollution and cardiovascular mortality or hospitalization for cardiac events. However the evidence regarding the association between air pollution and acute cardiac events, such as out-of-hospital cardiac arrest, is inconsistent. METHODS: We investigated the association between particulate matter (PM) air pollution and out-of-hospital cardiac arrest using a case-crossover study of adults (age, 35+ years) in Melbourne, Australia. We included 8434 cases identified through the Victorian Cardiac Arrest Registry from 2003 through 2006. We excluded arrests with an obvious preceding noncardiac event such as trauma, poisoning, or drowning, leaving only those events that were presumed to have cardiac etiology. Air pollution concentrations obtained from a central monitoring site were used for day of the arrest and for lag 1, lag 2, and lag 3, including the average lag 0-1. RESULTS: An interquartile range increase of 4.26 microg/m3 in PM2.5 over 2 days (lag 0-1) was associated with an increase in risk for an out-of-hospital cardiac arrest of 3.6% (95% confidence interval = 1.3% to 6.0%). PM10 and carbon monoxide also showed associations, but not as strong as for PM2.5. Longer lag periods did not show such strong relationships. There was no association of these cardiac events with ozone, sulfur dioxide, or nitrogen dioxide in any lag period. Individuals age 65-74 years old were most susceptible to PM2.5 exposure, while those 75 years and older had the lowest risk. CONCLUSION: These findings support an association between daily average PM2.5 concentrations and an increased risk of out-of-hospital cardiac arrests.

Is potroom asthma due more to sulphur dioxide than fluoride? An inception cohort study in the Australian aluminium industry.

OBJECTIVES: Although an asthma-like syndrome has been recognised in aluminium smelter workers for over 70 years, the causal agent has been difficult to identify. METHODS: An inception cohort study was conducted at two Australian aluminium smelters where 446 employees participated over a period of 9 years. Cumulative exposures between interviews were estimated from job histories using a task exposure matrix based on measurements in the smelters. Participants completed an MRC respiratory questionnaire, spirometry and methacholine challenge test. Data were analysed with generalised estimating equations to allow for repeated measurements of each participant. RESULTS: Wheeze and chest tightness, the two symptoms most closely related to asthma, showed associations with occupational exposures. SO(2) exposure was significantly associated with these symptoms, bronchial hyper-responsiveness (BHR) to methacholine (a feature of asthma), airflow limitation (reduced forced expiratory volume in 1 second/forced vital capacity ratio) and longitudinal decline in lung function. Fluoride exposure was associated with the same outcomes, but less strongly. Inhalable dust and the benzene soluble fraction (BSF) were associated with symptoms of asthma and BHR. Although many of the exposures were highly correlated, further modelling suggested that of the known respiratory irritants, SO(2) was more likely than fluoride to be primarily responsible for the symptoms observed. Fluoride, inhalable dust and SO(2) were the most important airborne contaminants associated with effects on lung function. CONCLUSIONS: The observed effects were detected at contaminant levels within occupational exposure standards, so further reductions are required, particularly in SO(2) exposures.

Cardiovascular Disease and Type 2 Diabetes Risk Across Occupational Groups and Industry in a Statewide Study of an Australian Working Population.

OBJECTIVE: The aim of this study was to investigate prevalence of type 2 diabetes (diabetes) and cardiovascular disease (CVD) risk in occupational and industry groups in a large, diverse working population. METHODS: Five hundred thousand Victorian workers undertook health checks, including lifestyle, anthropometric, and biomedical cardiovascular risk factor assessment. Five-year diabetes (AUSDRISK) and absolute CVD risk were estimated. RESULTS: High diabetes and CVD risk was increased in many occupational groups and industries relative to managers and Professional/Scientific/Technical Services, respectively. Significantly more blue-collar workers had high diabetes risk [males prevalence ratio (PR) 1.19 (95% confidence interval, 95% CI 1.17 to 1.20); females 1.34 (95% CI 1.30 to 1.38)], high CVD risk [males 1.45 (95% CI 1.37 to 1.53); females 1.48 (95% CI 1.17 to 1.88], and risk factors including smoking [males 2.26 (95% CI 2.22 to 2.30); females 2.20 (95% CI 2.13 to 2.27)], compared with white-collar workers. CONCLUSION: Targeting occupational and industry groups within sustainable workplace programs could assist in reducing chronic diseases, lowering sickness absence, and improving productivity.

Reproductive outcomes of maternal contamination with cyclodiene insecticides, hexachlorobenzene and beta-benzene hexachloride.

The effects of organochlorines on human reproduction have been recently under scrutiny. Some negative effects on animal reproduction have been reported. In this study we aimed to evaluate the effect of maternal contamination with a certain group of organochlorines, which are cyclodienes, HCB (hexachlorobenzene) and beta-BHC (beta-hexachlorocyclohexane) on human reproduction. Breast milk samples from 815 eligible Victorian mothers were used for measuring maternal contamination and the reproductive outcomes such as birth weight, head circumference and prematurity were taken from health files. Our study did not show any significant negative effect on outcomes such as birth weight, small for gestation age, previous miscarriage or still birth, head circumference or sex ratio. An inconsistent increase across oxychlordane exposure levels for prematurity was found. We also found an inverse association between the highest levels of HCB and oxychlordane with previous miscarriage or still birth; but this was based on small numbers and may be explained by loss of contaminants through the aborted fetus. These results suggest that the declining contamination levels of these chemicals do not impose a threat to human reproduction.

Pain-related musculoskeletal disorders, psychological comorbidity, and the relationship with physical and mental well-being in Gulf War veterans.

Occupational activities such as lifting loads, working in constrained spaces, and training increase the risk of pain-related musculoskeletal disorders (MSDs) in military veterans. Few studies have investigated MSD and psychological disorder in veterans, and previous studies had limitations. This cross-sectional study compared pain-related MSD and psychological comorbidity and well-being between 1381 male Australian 1990-1991 Gulf War veterans (veterans) and a military comparison group (n=1377, of whom 39.6% were serving and 32.7% had previously deployed). At a medical assessment, 2000-2002, reported doctor-diagnosed arthritis or rheumatism, back or neck problems, joint problems, and soft tissue disorders were rated by medical practitioners as nonmedical, unlikely, possible, or probable diagnoses. Only probable MSDs were analysed. Psychological disorders in the past 12 months were measured using the Composite International Diagnostic Interview. The Short-Form Health Survey (SF-12) assessed 4-week physical and mental well-being. Almost one-quarter of veterans (24.5%) and the comparison group (22.4%) reported an MSD. Having any or specific MSD was associated with depression and posttraumatic stress disorder (PTSD), but not alcohol disorders. Physical and mental well-being was poorer in those with an MSD compared to those without, in both study groups (eg, veterans with any MSD, difference in SF-12 physical component summary scale medians = -10.49: 95% confidence interval -12.40, -8.57), and in those with MSD and psychological comorbidity compared with MSD alone. Comorbidity of any MSD and psychological disorder was more common in veterans, but MSDs were associated with depression, PTSD, and poorer well-being in both groups. Psychological comorbidity needs consideration in MSD management. Longitudinal studies are needed to assess directionality and causality.

Cancer incidence and soil arsenic exposure in a historical gold mining area in Victoria, Australia: a geospatial analysis.

Soil and mine waste around historical gold mining sites may have elevated arsenic concentrations. Recent evidence suggests some systemic arsenic absorption by residents in the goldfields region of Victoria, Australia. Victorian Cancer Registry and geochemical data were accessed for an ecological geographical correlation study, 1984-2003. Spatial empirical Bayes smoothing was applied when estimating standardised incidence ratios (SIRs) for cancers in 61 statistical local areas. The derived soil arsenic exposure metric ranged from 1.4 to 1857 mg/kg. Spatial autoregressive modelling detected increases in smoothed SIRs for all cancers of 0.05 (95% confidence interval (CI), 0.02-0.08) and 0.04 (0.01-0.07) per 2.7-fold increase in the natural log-transformed exposure metric for males and females, respectively, in more socioeconomically disadvantaged areas; for melanoma in males (0.05 (0.01-0.08) adjusted for disadvantage) and females (0.05 (0.02-0.09) in disadvantaged areas). Excess risks were estimated for all cancers (relative risk 1.21 (95% CI, 1.15-1.27) and 1.08 (1.03-1.14)), and melanoma (1.52 (1.25-1.85) and 1.29 (1.08-1.55)), for males and females, respectively, in disadvantaged areas in the highest quintile of the exposure metric relative to the lowest. Our findings suggest small but significant increases in past cancer risk associated with increasing soil arsenic in socioeconomically disadvantaged areas and demonstrate the robustness of this geospatial approach.

Cancer incidence, mortality, and blood lead levels among workers exposed to inorganic lead.

PURPOSE: We aimed to measure mortality and cancer incidence in a cohort of lead-exposed workers by using blood lead levels to assess exposure. METHODS: The cohort comprised male lead workers. Subjects were matched to cancer and death registries. Observed death and cancer incidence rates were compared with population rates to obtain standardized mortality ratios (SMR) and standardized incidence ratios (SIR). RESULTS: There were 4114 male subjects with average follow-up time of 16.2 years, and 406 deaths were observed. There were significant results for overall death (SMR, 111; 95% confidence interval [95% CI], 101-123), digestive system deaths (SMR, 167; 95% CI, 110-250), and deaths from external causes (SMR, 135; 95% CI, 105-174). A total of 228 subjects had cancer, with an overall SIR of 83 (95% CI, 73-95); liver cancer SIR of 217 (95% CI, 103-454) and esophageal cancer SIR of 240 (95% CI, 129-447). The latter was seven-fold greater (SIR 755; 95% CI, 314-1813) among those with a blood lead level result above 30 µg/dL compared with population rates. No other increases in cancers were observed. CONCLUSIONS: Overall mortality was elevated. Although incidence rates of overall cancer were low, further studies and analysis are required to investigate any biologically plausible associations between inorganic lead and liver or esophageal cancer.

Maternal contamination with PCBs and reproductive outcomes in an Australian population.

Polychlorinated biphenyls used previously in industry are widespread environmental contaminants under scrutiny for their possible reproductive effects in humans. In this study, 200 breast milk samples from eligible Victorian mothers were used for measuring maternal contamination and their possible effect on the offspring was investigated. No significant association was found between maternal PCB contamination and low birth weight, small for gestational age and previous miscarriage or stillbirth. The elevated odd ratios of prematurity, increased with increase in contamination level but were nonsignificant. Higher PCB contamination was not in favor of any gender in the offspring. Our results suggest that chronic, low contamination with PCBs does not pose a reproduction threat in humans.