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.

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.

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.

Low birth-weight, microcephalic malformation syndrome in a 46,XX girl and her 46,XY sister with agonadism: third report of the Kennerknecht syndrome or autosomal recessive Seckel-like syndrome with previously undescribed genital anomalies.

We report on two sisters, one 46,XX with normal female phenotype, the other 46,XY with ambiguous external genitalia and agonadism. Both have a low birth weight and microcephalic malformation syndrome leading to early death. The 46,XX patient also had a diaphragmatic defect. The XY sister, in addition to absence of gonads and Mùllerian and Wolffian derivatives, had severe hypoplasia of the pulmonary artery and its branches, multicystic kidneys, and pachygyria. This combination of malformations, in part, fits in the autosomal recessive condition described by Kennerknecht et al. [1993] in a 46,XX and 46,XY pair of sibs with agonadism. The craniofacial appearance of our patients is similar to that observed in the 46,XY sister with agonadism reported by Kennerknecht et al. [1995]. On the other hand, intrauterine growth retardation, microcephaly, and pachygyria are not part of the phenotype of the Kennerknecht "syndrome" and agonadism was not present in our 46,XX patient. We suggest two hypotheses to explain the abnormal phenotype in our cases. The first is that they might represent the third sibship affected by the Kennerknecht syndrome with additional anomalies. Alternatively, our two sibs might have a Seckel or a Seckel-like syndrome. The 46,XY patient would then be the first case of Seckel syndrome with sex reversal and agonadism.