Bauxite mine and alumina refinery workers: mortality and cancer risk.

BACKGROUND: Aluminium industry workers are at risk of long-term health consequences. AIMS: To investigate mortality and cancer incidence in bauxite mine and alumina refinery workers. METHODS: A pre-existing cohort of workers was re-linked with the Australian National Death Index, and the Australian Cancer Database to provide additional death (7 years) and cancer (9 years) data. Standardized mortality ratios (SMRs) and standardized incidence rates (SIRs) were estimated by job category, duration of employment and time since first employment. RESULTS: Linkage was performed for 6935 (6207 male) workers. Compared with the general population, there was a reduced or similar risk of death for mine/refinery workers for all causes except mesothelioma which was increased amongst male production workers [SMR 2.42, 95% CI 1.11-4.60]. Mesothelioma incidence was also increased amongst males [SIR 2.50, 95% CI 1.60-3.71]. Male office workers had a greater incidence of prostate cancer [SIR 1.30, 95% CI 1.06-1.57] and thyroid cancer [SIR 3.47, 95% CI 1.66-6.38]. Melanoma incidence was increased in female office workers [SIR 2.27, 95% CI 1.36-3.54]. Lip cancer incidence was increased in male maintenance/production workers [SIR 2.04, 95% CI 1.02-3.65]. Overall cancer incidence was otherwise similar to the general Australian population. CONCLUSIONS: Overall risk of death and incidence of cancer for bauxite mine and alumina refinery workers was similar to the general population. Incidence and risk of death from mesothelioma were higher, likely due to historic asbestos exposure in this and other industries. The increased risk of melanoma, lip, prostate and thyroid cancers requires further investigation.

Serum angiotensin converting enzyme elevation in association with artificial stone silicosis.

BACKGROUND: Silicosis is a rapidly emerging major health concern for workers in the artificial stone benchtop industry. The association between serum angiotensin converting enzyme (sACE) levels and artificial stone silicosis is unknown. METHODS: We investigated 179 male workers (median age 40 years, interquartile range (IQR) 33-48 years) from the stone benchtop industry in Victoria, Australia. All had worked in an environment where dry processing of artificial stone had occurred and were registered with the Victorian Silica-associated Disease Registry between June 2019 and August 2020. Workers had undergone protocolised assessments including respiratory function testing, high resolution CT chest and blood tests panel, including sACE. FINDINGS: Sixty workers with artificial stone silicosis were identified and they had a higher median sACE level (64.1 U/L, IQR 51.5, 87.5), compared to 119 without silicosis (35.0 U/L, IQR 25.0, 47.0). Compared to those with a normal assessment, regression modelling noted significantly higher average differences in sACE levels for workers with lymphadenopathy alone (12.1 U/L, 95% confidence interval (CI): 1.3, 22.9), simple silicosis (28.7 U/L, 95% CI: 21.3, 36.0) and complicated silicosis (36.0 U/L, 95% CI 25.2, 46.9). There was a small negative association with gas transfer, but no associations with exposure duration or spirometry. CONCLUSION: sACE levels were noted to be higher in artificial stone workers with silicosis compared to those without disease and was highest in those with complicated silicosis. Longitudinal follow up is required to evaluate sACE as a prognostic biomarker for workers with this rapidly emerging occupational lung disease.

Mortality and cancer incidence in a cohort of male paid Australian firefighters.

OBJECTIVES: To investigate mortality and cancer incidence of paid male Australian firefighters and of subgroups of firefighters by era of first employment, duration of employment and number and type of incidents attended. METHODS: Participating fire agencies supplied records of individual firefighters including their job histories and incidents attended. The cohort was linked to the Australian National Death Index and Australian Cancer Database. SMRs and SIRs were calculated. Firefighters were grouped into tertiles by duration of employment and by number of incidents attended and relative mortality ratios and relative incidence ratios calculated. Analyses were carried out separately for full-time and part-time male firefighters. RESULTS: Compared to the Australian population, there were significant increases in overall risk of cancer, for all paid firefighters SIR 1.09 (95% CI 1.03 to 1.14), in prostate cancer, full-time firefighters 1.23 (95% CI 1.10 to 1.37), part-time 1.51 (1.28 to 1.77), and melanoma full-time 1.45 (95% CI 1.26 to 1.66), part-time firefighters 1.43 (95% CI 1.15 to 1.76). Kidney cancer was associated with longer service in internal analyses for paid firefighters. Prostate cancer was associated with longer service and increased attendance at fires, particularly structural fires for full-time firefighters.The overall risk of mortality was significantly decreased and almost all major causes of death were significantly reduced for paid firefighters. CONCLUSIONS: Male paid firefighters have an increased risk of cancer. They have reduced mortality compared with the general population, which is likely to be a result of a strong healthy worker effect and likely lower smoking rates among firefighters compared with the Australian population.

Mortality and cancer incidence at a fire training college.

BACKGROUND: An investigation into concerns about possible health effects of fire training practices at an Australian training facility recommended a study to investigate the risk of cancer and mortality of those with risk of chronic occupational exposure to several chemicals. AIMS: To investigate mortality and cancer incidence in firefighters at the Country Fire Authority (CFA) Fiskville training facility, Victoria, Australia, between 1971 and 1999. METHODS: CFA supplied human resources records, supplemented by self-reported information for a retrospective cohort, and allocated firefighters to low, medium or high groups based on probability of exposure. We linked the cohort to state and national cancer and mortality data. We calculated standardized mortality ratios and standardized cancer incidence ratios (SIRs). RESULTS: The high group (n = 95) had a clearly increased risk of overall cancers SIR = 1.85 (95% CI 1.20-2.73), testicular cancer SIR = 11.9 (1.44-42.9) and melanoma SIR = 4.59 (1.68-9.99) relative to the population of Victoria. Brain cancer was significantly increased for the medium group (n = 256): SIR = 5.74 (1.56-14.7). Mortality was significantly reduced for all groups. CONCLUSIONS: Dealing with supplied records can be problematic but despite the small numbers, we identified an increased risk of cancer for the high group. The mortality data suggested that there was under-ascertainment for the medium and low groups which underestimated risk and a possible reporting bias for brain cancer. Small cohorts can still provide statistically significant findings when investigating locations for cancer risk.

Stability of symptom patterns in Australian Gulf War veterans: 10-year longitudinal study.

OBJECTIVES: Previously we established that symptoms reported by 1990-1991 Gulf War veterans were correlated and exhibited a pattern with 3 factors (psychophysiological distress, somatic distress and arthroneuromuscular distress), and this pattern was similar to that observed in a military comparison group. In this follow-up study, we examined whether the patterns of symptomatology have changed over time. METHODS: Using data on 56 symptoms that was collected in 2000-2003 (wave 1) and 2011-2012 (wave 2) from an Australian cohort of Gulf War veterans (veterans) and a military comparison group, exploratory factor analysis was conducted and Tucker's Congruence Coefficient (TCC) was used to determine factor structure similarity across study groups and waves. RESULTS: The results showed that the 3 factors observed at wave 1 were still present at wave 2, and factor structures across study groups and study waves were fairly similar, with TCC ranging 0.86-0.92. Veterans consistently reported more symptoms across all 3 factors. Veterans' symptomatology specific to psychophysiological distress increased between waves 1 and 2 (ratio of means 1.15; 95% CI 1.07 to 1.25) but psychophysiological distress symptomatology was constant in the comparison group (ratio of means 0.97; 95% CI 0.89 to 1.06). Somatic and arthroneuromuscular distress symptomatology significantly increased over time for both study groups, although at a similar rate. CONCLUSIONS: While the symptom groupings (measured by the 3 factors) remained unchanged at 10 years of follow-up, and remained comparable between Gulf War and comparison group, symptomatology continued to be elevated in Gulf War veterans than in the comparison group, and was most evident for psychophysiological distress.

Depression in Gulf War veterans: a systematic review and meta-analysis.

BACKGROUND: Although post-traumatic stress disorder (PTSD) has been a focus of attention in 1990/1991 Gulf War veterans, the excess risk of depression has not been clearly identified. We investigated this through a systematic review and meta-analysis of studies comparing depression in Gulf War veterans to depression in a comparison group of non-deployed military personnel. METHOD: Multiple electronic databases and grey literature were searched from 1990 to 2012. Studies were assessed for eligibility and risk of bias according to established criteria. RESULTS: Of 14 098 titles and abstracts assessed, 14 studies met the inclusion criteria. Gulf War veterans had over twice the odds of experiencing depression [odds ratio (OR) 2.28, 95% confidence interval (CI) 1.88-2.76] and dysthymia or chronic dysphoria (OR 2.39, 95% CI 2.0-2.86) compared to non-deployed military personnel. This finding was robust in sensitivity analyses, and to differences in overall risk of bias and psychological measures used. CONCLUSIONS: Despite divergent methodologies between studies, depression and dysthymia were twice as common in Gulf War veterans and are important medical conditions for clinicians and policymakers to be aware of in managing Gulf War veterans' health.

Is there a relationship between occupational activities and low back pain in obese, middle-aged women?

BACKGROUND: Although low back pain and obesity are major health issues for women, our understanding of the relationship between these conditions is limited. This study aimed to investigate the relationship between occupational activities and low back pain and disability in obese and non-obese, middle-aged females. METHODS: Eighty-nine obese and 56 non-obese participants were recruited for a community-based study of musculoskeletal health. Low back pain intensity and disability were examined using the Chronic Pain Grade Questionnaire and participants were asked about their involvement in occupational activities. RESULTS: More manual activity and heavy lifting, bending or squatting were found to be associated with low back pain intensity in obese females (odds ratio (OR) 1.83, 95% confidence interval (CI) 1.14-2.94; OR 3.02, 95% CI 1.24-7.37, respectively), but not in non-obese females (OR 0.83, 95% CI 0.42-1.63; OR 0.81, 95% CI 0.25-2.6, respectively), after adjusting for age and recreational activity. Similarly, there were also relationships between performance of more manual activity and heavy lifting, bending or squatting and low back disability in the obese (OR 1.68, 95% CI 1.07-2.63; OR 2.79, 95% CI 1.21-6.46, respectively), but not in the non-obese (OR 0.88, 95% CI 0.36-2.13; OR 1.78, 95% CI 0.39-8.22, respectively). CONCLUSIONS: Obese females who perform predominately manual activity or heavy lifting, bending or squatting at work have high levels of low back pain and disability, independent of their recreational activity. This was not the case for non-obese, female workers. Although longitudinal investigation is needed, these findings highlight the role of obesity in low back pain and disability for middle-aged females in occupational settings.

Suicide in Australian pesticide-exposed workers.

BACKGROUND: Epidemiological research has observed that workers with exposure to anticholinesterase pesticides, and particularly those with a history of acute overexposure, may be at increased risk of depression. However, there is little published research about the risk of suicide in relation to pesticide exposure. AIMS: To investigate risk of suicide in relation to metrics of pesticide exposure and type of work. METHODS: A nested case-control study was performed within a retrospective cohort study of pesticide-exposed workers from various industries. Ninety male suicide deaths and 270 male controls were matched by age bands, state of residence and live status. Cholinesterase inhibition was determined using subject-specific biomonitoring records collected at the time of exposure. RESULTS: Suicide risk was not significantly elevated in relation to exposure to any particular pesticide classes nor in relation to pesticide overexposure, confirmed by blood test. While the risk of suicide associated with a history of cholinesterase inhibition was raised, this was not significant (odds ratio = 1.90, 95% confidence interval = 0.73-4.93). CONCLUSIONS: This study did not find an elevated suicide risk associated with use of any major class of pesticide and there was little evidence that overexposure was associated with increased risk of suicide. A non-significant association between overexposure to anticholinesterase pesticides may be consistent with previous research showing increased depression in workers with a history of cholinesterase inhibition and warrants further investigation.

Use of mobile phones and changes in cognitive function in adolescents.

BACKGROUND: Several studies have investigated the impact of mobile phone exposure on cognitive function in adults. However, children and adolescents are of special interest due to their developing nervous systems. METHODS: Data were derived from the Australian Mobile Radiofrequency Phone Exposed Users' Study (MoRPhEUS) which comprised a baseline examination of year 7 students during 2005/2006 and a 1-year follow-up. Sociodemographic and exposure data were collected with a questionnaire. Cognitive functions were assessed with a computerised test battery and the Stroop Color-Word test. RESULTS: 236 students participated in both examinations. The proportion of mobile phone owners and the number of voice calls and short message services (SMS) per week increased from baseline to follow-up. Participants with more voice calls and SMS at baseline showed less reductions in response times over the 1-year period in various computerised tasks. Furthermore, those with increased voice calls and SMS exposure over the 1-year period showed changes in response time in a simple reaction and a working memory task. No associations were seen between mobile phone exposure and the Stroop test. CONCLUSIONS: We have observed that some changes in cognitive function, particularly in response time rather than accuracy, occurred with a latency period of 1 year and that some changes were associated with increased exposure. However, the increased exposure was mainly applied to those who had fewer voice calls and SMS at baseline, suggesting that these changes over time may relate to statistical regression to the mean, and not be the effect of mobile phone exposure.

Surveillance of Australian workplace Based Respiratory Events (SABRE) in New South Wales.

BACKGROUND: The Surveillance of Australian workplace Based Respiratory Events (SABRE) New South Wales (NSW) scheme is a voluntary notification scheme established to determine the incidence of occupational lung diseases in NSW Australia. AIMS: Data presented in this paper summarize the last 7 years of reporting to SABRE (June 2001 to December 2008). METHODS: Every 2 months, participating occupational physicians, respiratory physicians and general practitioners (accredited by the NSW WorkCover Authority) reported new cases of occupational lung disease seen in their practices. Data collected include gender, age, causal agent and the occupations and industries believed responsible. Estimated incidence was calculated for each disease. RESULTS: Three thousand six hundred and fifty-four cases were notified to the scheme, consisting of 3856 diagnoses. Most of the cases were males (76%). Pleural plaques [1218 (28%)] were the most frequently reported condition, followed by mesothelioma [919 (24%)]. Silicosis [90 (2%)] and occupational asthma [OA; 89 (2%)] were the most frequently reported non-asbestos-related diseases. Estimated rates for mesothelioma, diffuse pleural thickening (DPT) and OA were 83, 83 and 5 cases per million employed males per year, respectively. Trades such as carpenters and electricians associated with the building industry, electricity supply and asbestos product manufacture were the most common occupations and industries reported. CONCLUSIONS: Asbestos-related diseases are the most frequently reported conditions to SABRE NSW. The very low incidence of OA for NSW most likely reflects under-diagnosis as well as under-reporting. Occupational lung disease is still occurring in NSW despite current preventative strategies. The SABRE scheme currently provides the only available information in this area.

Cancer incidence and mortality in a historical cohort of Australian pest control workers.

OBJECTIVES: To determine the rates of mortality and incident cancer in a historical cohort of pest control operators. METHODS: A retrospective cohort was assembled from former state government occupational health surveillance programmes. This cohort was linked to the Australian national registries of cancer and mortality and the results were compared with the general Australian population rates. RESULTS: 125 deaths and 89 incident cancers were found during the periods of observation (mortality 1983-2004 and cancer 1983-2002). Overall cancer incidence and mortality rates were not found to be significantly different from the general population. Among the specific causes of death, suicide (standardised mortality ratio; SMR 1.78; 95% CI 1.12 to 2.83) and unintentional falls (SMR 4.57; 95% CI 1.72 to 12.19) were significantly in excess, although the latter was based on only 4 deaths. Melanoma was the only specific incident cancer found significantly in excess (standardised incidence ratio 1.56; 95% CI 1.03 to 2.37). CONCLUSIONS: Pest control workers have overall mortality and cancer rates similar to the general population. Excess rates of incident melanoma and intentional self-poisoning mortality are of concern and warrant further investigation. Follow-up of this cohort as its members age, will provide more insight into these possible associations.

Life satisfaction and quality in Korean War veterans five decades after the war.

BACKGROUND: Military service is considered to be a hidden variable underlying current knowledge about well-being in the elderly. This study aimed to examine life satisfaction and quality of life in Australia's surviving male Korean War veterans and a community comparison group, and to investigate any association with war deployment-related factors. METHODS: Participants completed a postal questionnaire which included the Life Satisfaction Scale, the brief World Health Organization Quality of Life (WHOQOL-Bref) questionnaire and the Combat Exposure Scale. RESULTS: Korean War veterans reported significantly lower Percentage Life Satisfaction (PLS) and quality of life scores on four WHOQOL-Bref domains, compared with similarly aged Australian men (each p value <0.001). These outcomes were most strongly associated with severity of combat exposure and low rank. Mean PLS was approximately 15% lower in veterans who reported heavy combat compared with those reporting no combat, and approximately 12% lower in enlisted ranked veterans compared with officers. CONCLUSIONS: Fifty years after the Korean War, life satisfaction and quality in Australian veterans is poor relative to other Australian men, and is associated with deployment-related factors including combat severity and low rank. In order to respond effectively to current and projected population health needs, nations with large veteran populations may need to consider the impact of military service on well-being in later life.

Relationships between alumina and bauxite dust exposure and cancer, respiratory and circulatory disease.

OBJECTIVES: To examine the associations between alumina and bauxite dust exposure and cancer incidence and circulatory and respiratory disease mortality among bauxite miners and alumina refinery workers. METHODS: This cohort of 5770 males has previously been linked to national mortality and national and state cancer incidence registries (1983-2002). In this paper, Poisson regression was used to undertake internal comparisons within the cohort based on subgroups of cumulative exposure to inhalable bauxite and alumina dust. Exposure was estimated using job histories and historical air monitoring data. RESULTS: There was no association between ever bauxite exposure and any of the outcomes. There was a borderline significant association between ever alumina exposure and cerebrovascular disease mortality (10 deaths, RR 3.8, 95% CI 1.1 to 13). There was some evidence of an exposure-response relationship between cumulative bauxite exposure and non-malignant respiratory disease mortality (seven deaths, trend p value: 0.01) and between cumulative alumina exposure and cerebrovascular disease mortality (trend p value: 0.04). These associations were based on very few cases and for non-malignant respiratory disease the deaths represented a heterogeneous mixture of causes. There was no evidence of an excess risk for any cancer type with bauxite or alumina exposure. CONCLUSIONS: These preliminary findings, based on very few cases, suggest that cumulative inhalable bauxite exposure may be associated with an excess risk of death from non-malignant respiratory disease and that cumulative inhalable alumina dust exposure may be associated with an excess risk of death from cerebrovascular disease. Neither exposure appears to increase the risk of incident cancers.

Mortality and cancer incidence in workers in two Australian prebake aluminium smelters.

BACKGROUND: Exposures in the aluminium production industry have been declining and this study aimed to investigate cancer and mortality in two Australian prebake aluminium smelters. METHODS: The cohort included 4396 males who had worked in a prebake smelter for at least 3 months. They were matched against the National Death Index and the National Cancer Statistics Clearing House to obtain cause of death and type of cancer. Standardised Mortality Ratios (SMRs) and Standardised Incidence Ratios (SIRs) were calculated for the whole cohort, for production or maintenance work categories and for duration of employment categories. RESULTS: The SMRs for all causes, circulatory, respiratory and injury deaths were at or below expected. Mesothelioma was the only significantly increased cause of death (SMR 3.52, 95% CI 1.47 to 8.46). Death from prostate cancer in production workers was elevated (SMR 2.39, 95% CI 1.29 to 4.44) and in those who had worked for more than 20 years in production or maintenance jobs (SMR 3.67, 95% CI 1.53 to 8.81). There were statistically significant excesses of incident stomach cancer, mesothelioma, and kidney cancer cases, while the SIR for melanoma was significantly reduced. There was no significant trend for duration of exposure for any type of incident cancer. CONCLUSIONS: This study found no overall excess of mortality or cancer, but incident mesothelioma and kidney cancer risks were elevated. The lack of excess risk for lung or bladder cancer or deaths from respiratory disease may be related to the different level and pattern of exposure between Søderberg and prebake smelters.

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

Persistent organochlorine pesticides, such as dichlorodiphenyltrichloroethane (DDT), are lipophilic environmental pollutants which accumulate in the food chain. These chemicals have long half-lives and can be detected in human milk, serum, and some other tissues. These chemicals have recently been under scrutiny for their possible health hazards such as cancer and reproductive outcomes including low birth weight. The aim of our study was to investigate whether mothers with a higher contamination of pesticides were different from mothers with low contamination in relation to their offspring's birth outcomes such as birth weight, small for gestation age, prematurity, head circumference, sex ratio, and previous miscarriage or still birth. We used data collected as part of a cross-sectional study of organochlorines in breast milk. This study did not show any association between low birth weight or small for gestation age and organochlorine contamination when comparing the higher to the low exposure group. Weak, significant correlations (-0.1) were detected between low birth weight and contamination levels of dichlorodiphenyldichloroethylene (DDE) only in female offspring. There was a decrease in the percentage of female offspring for all chemicals in the high-contamination group. The baby's head circumference increased as the mother's contamination increased but the adjusted difference in means was not significant. We did not see any association between either miscarriage or stillbirth in the mother's previous pregnancies or prematurity of the first live (recent) baby when comparing the higher to the low exposure mothers. The organochlorines DDT and DDE were not found to be associated with adverse birth outcomes in contaminated mothers in the range of contamination of our population (<7.5 mg/kg lipid in maternal milk), although there is weak evidence that sex ratio may be affected.

Biological dust exposure in the workplace is a risk factor for chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality. Although the main risk factor is smoking, 15-19% of COPD even in smokers has been attributed to occupational exposures. The aim of this study was to investigate the association between occupational exposure and risk of COPD. METHODS: Participants were part of a cross sectional study of risk factors for COPD. A total of 1232 completed a detailed respiratory questionnaire, spirometric testing and measurement of gas transfer. Job histories were coded according to the International Standard Classification of Occupations. These codes were then used to establish occupational exposures using the ALOHA job exposure matrix. RESULTS: The prevalence of emphysema was 2.4%, chronic obstructive bronchitis 1.8%, and COPD 3.4%. Subjects ever exposed to biological dusts had an increased risk of chronic obstructive bronchitis (OR 3.19; 95% CI 1.27 to 7.97), emphysema (OR 3.18; 95% CI 1.41 to 7.13), and COPD (OR 2.70, 95% CI 1.39 to 5.23). These risks were higher in women than in men. For biological dust, the risk of emphysema and COPD was also significantly increased in both the duration of exposure categories, again in women but not in men. No significant increased risks for COPD were found for mineral dust (OR 1.13; 95% CI 0.57 to 2.27) or gases/fumes (OR 1.63; 95% CI 0.83 to 3.22). CONCLUSION: In this general population sample of adults, occupational exposures to biological dusts were associated with an increased risk of COPD which was higher in women. Preventive strategies should be aimed at reducing exposure to these agents in the workplace.

Health Watch exposure estimates: do they underestimate benzene exposure?

A nested case-control study found that the excess of leukemia, identified among the male members of the Health Watch cohort, was associated with benzene exposure. Exposure had been retrospectively estimated for each individual occupational history using an algorithm in a relational database. Benzene exposure measurements, supplied by Australian petroleum companies, were used to estimate exposure for specific tasks. The tasks carried out within each job, the products handled, and the technology used, were identified from structured interviews with contemporary colleagues. More than half of the subjects started work after 1965 and had an average exposure period of 20 years. Exposure was low; nearly 85% of the cumulative exposure estimates were at or below 10 ppm-years. Matched analyses showed that leukemia risk increased with increasing cumulative benzene exposures and with increasing exposure intensity of the highest-exposed job. Non-Hodgkin lymphoma and multiple myeloma were not associated with benzene exposure. A reanalysis reported here, showed that for the 7 leukemia case-sets with greater than 16 ppm-years cumulative exposure, the odds ratio was 51.9 (5.6-477) when compared to the 2 lowest exposed categories combined to form a new reference category. The addition of occasional high exposures, e.g. as a result of spillages, increased exposure for 25% of subjects but for most, the increase was less than 5% of total exposure. The addition of these exposures reduced the odds ratios. Cumulative exposures did not range as high as those in comparable studies; however, the recent nature of the cohort and local handling practices can explain these differences.

Symptoms and medical conditions in Australian veterans of the 1991 Gulf War: relation to immunisations and other Gulf War exposures.

AIMS: To investigate whether Australian Gulf War veterans have a higher than expected prevalence of recent symptoms and medical conditions that were first diagnosed in the period following the 1991 Gulf War; and if so, whether these effects were associated with exposures and experiences that occurred in the Gulf War. METHODS: Cross-sectional study of 1456 Australian Gulf War veterans and a comparison group who were in operational units at the time of the Gulf War, but were not deployed to that conflict (n = 1588). A postal questionnaire was administered and the likelihood of the diagnosis of self-reported medical conditions was assessed and rated by a medical practitioner. RESULTS: Gulf War veterans had a higher prevalence of all self-reported health symptoms than the comparison group, and more of the Gulf War veterans had severe symptoms. Increased symptom reporting was associated with several exposures, including having more than 10 immunisations, pyridostigmine bromide tablets, anti-biological warfare tablets, pesticides, insect repellents, reportedly being in a chemical weapons area, and stressful military service experiences in a strong dose-response relation. Gulf War veterans reported psychological (particularly post-traumatic stress disorder), skin, eye, and sinus conditions first diagnosed in 1991 or later more commonly than the comparison group. Over 90% of medical conditions reported by both study groups were rated by a medical practitioner as having a high likelihood of diagnosis. CONCLUSION: More than 10 years after the 1991 Gulf War, Australian veterans self-report all symptoms and some medical conditions more commonly than the comparison group. Further analysis of the severity of symptoms and likelihood of the diagnosis of medical conditions suggested that these findings are not due to over-reporting or to participation bias.