Ascertainment of occupational histories in the working population: the occupational history calendar approach.

BACKGROUND: self-reported occupational histories are an important means for collecting historical data in epidemiological studies. An occupational history calendar (OHC) has been developed for use alongside a national occupational hazard surveillance tool. This study presents the systematic development of the OHC and compares work histories collected via this calendar to those collected via a traditional questionnaire. METHODS: the paper describes the systematic development of an OHC for use in the general working population. A comparison of data quality and recall was undertaken in 51 participants where both tools were administered. RESULTS: the OHC enhanced job recall compared with the traditional questionnaire. Good agreement in the data captured by both tools was observed, with the exception of hazard exposures. CONCLUSIONS: a calendar approach is suitable for collecting occupational histories from the general working population. Despite enhancing job recall the OHC approach has some shortcomings outweighing this advantage in large-scale population surveillance.

Assessing individual employee risk factors for occupational asthma in primary aluminium smelting.

AIMS: To assess the significance of individual risk factors in the development of occupational asthma of aluminium smelting (OAAS). METHODS: A matched case-control study nested in a cohort of 545 workers employed in areas with moderate to high levels of smelting dust and fume. The cohort comprised those who had their first pre-employment medical examination between 1 July 1982 and 1 July 1995; follow up was until 31 December 2000. Forty five cases diagnosed with OAAS and four controls per case were matched for the same year of pre-employment and age within +/-5 years. The pre-employment medical questionnaires were examined, blinded as to case-control status, and information obtained on demographics and details of allergic symptoms, respiratory risk factors, respiratory symptoms, and spirometry. Data from the subsequent medical notes yielded subsequent history of hay fever, family history of asthma, full work history, date of termination or diagnosis, and tobacco smoking history at the end-point. RESULTS: There was a significant positive association between hay fever diagnosed either at or during employment and OAAS (adjusted OR 3.58, 95% CI 1.57 to 8.21). A higher forced expiratory ratio (FEV1/FVC%) at employment reduced the risk of developing OAAS (adjusted OR 0.93, 95% CI 0.88 to 0.99). The risk of OAAS was more than three times higher in individuals with an FER of 70.0-74.9% than in individuals with an FER > or =80.0% (adjusted OR 3.46, 95% CI 1.01 to 11.89). CONCLUSIONS: Individuals with hay fever may be more susceptible to occupational asthma when exposed to airborne irritants in aluminium smelting. The pathological basis may be reduced nasal filtration and increased bronchial hyperresponsiveness.

Historical cohort study of a New Zealand foundry and heavy engineering plant.

OBJECTIVES: To investigate the mortality of workers who had been exposed to asbestos, machining fluids and foundry work in a foundry and heavy engineering plant in the railway rolling stock manufacturing industry in New Zealand. METHODS: Historical cohort study design. RESULTS: For the total workforce of 3522 men employed between 1945 and 1991, follow up was 90% of person-years to 31 December 1991. Significantly increased standardised mortality ratios (SMRs) were found for all causes of death combined (SMR 1.07; 95% confidence interval (95% CI) 1.01 to 1.14), all malignancies (SMR 1.15; 95% CI 1.01 to 1.31), circulatory (SMR 1.16; 95% CI 1.07 to 1.27) and musculoskeletal diseases (SMR 3.06; 95% CI 1.39 to 5.84), all digestive cancers (SMR 1.29; 95% CI 1.04 to 1.59), all respiratory cancers (SMR 1.34; 95% CI 1.08 to 1.65), cancer of the oesophagus (SMR 1.97; 95% CI 1.01 to 3.45), and mesothelioma of the pleura (SMR 6.58; 95% CI 1.24 to 19.49). Three deaths from pleural mesothelioma were recorded, with latency times of 51, 53, and 57 years. There were no dose-response relations between exposure to asbestos, machining fluids or foundry work, or by duration of employment in the plant, and any cause of death. CONCLUSIONS: This study found small increases in risk for several causes of death among foundry and heavy engineering workers; however, these increases were small and the possible effects of smoking and other lifestyle factors could not be excluded. There was evidence of asbestos related disease in those involved in engineering work in the past.

Male cancer incidence by occupation: New Zealand, 1972-1984.

BACKGROUND: This study was carried out to identify male occupational groups with increased incidence of cancer for the period 1972-1984 in New Zealand. No data on cancer incidence by occupation have been reported previously for New Zealand. METHODS: Age (SIR1) and age and socioeconomic level (SIR2) standardized incidence ratios were calculated for males 15-64 years for all cancers combined and for site-specific cancers by occupational group. Directly age standardized rates were also calculated by socioeconomic level. RESULTS: In general, occupations in higher socioeconomic levels had lower all-cancer incidence ratios and lower socioeconomic levels had higher ratios. However, the highest socioeconomic level (level 1) had a higher all-cancer incidence rate than levels 2-6. After socioeconomic adjustment in increased incidence ratio for lung cancer was found for jewellery and precious metal workers (SIR2 = 241; 95% confidence interval [CI]: 116-146), and bricklayers and carpenters (SIR2 = 130; 95% CI: 120-433), Woodworkers had increased ratios for stomach (SIR2 = 144; 95% CI: 110-186) and rectal cancer (SIR2 = 146; 95% CI: 116-181). Firefighters had an increase for laryngeal cancer (SIR2 = 1074; 95% CI: 279-2776). CONCLUSIONS: Research appears to be warranted to further investigate associations of laryngeal cancer in firefighters, lung cancer in jewellery and precious metal workers and bricklayers and carpenters, and digestive cancers in woodworkers.

Male cancer mortality by occupation: 1973-86.

AIM: To identify male occupational groups with increased risk of death from cancer in 1973-86. METHOD: Age and social class standardised mortality ratios were calculated for males 15-64 years for all cancers combined and for site specific cancers by occupational group. RESULTS: In general, higher socio-economic groups had a lower all cancer mortality and lower socio-economic groups a higher mortality. After standardisation for age and social class, mortality ratios were increased for lung cancer in bricklayers and carpenters (SMR = 125; 95% CI: 110-141), machine tool operators (SMR = 218; 95% CI: 131-342), and welders (SMR = 140; 95% CI: 120-161), with the first group also having an increased risk for pleural mesothelioma (SMR = 222; 95% CI: 70-522). Malignant melanoma risk was increased in clerical workers (SMR = 147; 95% CI: 106-199) and not in outdoor occupations. Colon cancer mortality risk was increased in managers (SMR = 125; 95% CI: 104-148), and woodworkers (SMR = 147; 95% CI: 115-186). Stomach cancer mortality risk was raised for machine tool operators (SMR = 357; 95% CI: 128-782). Painters had an increased ratio for multiple myeloma (SMR = 352; 95% CI: 140-729) and machine tool operators an increase for leukaemia (SMR = 172; 95% CI: 45-446). CONCLUSIONS: The use of routinely collected data to examine cancer mortality by occupation is a useful method to identify groups with increased risks and provide information for hypothesis generation. Further research may be warranted to investigate lung and digestive cancers in woodworkers and machine tool operators, and cancer of the haemopoietic and lymphatic systems in painters and machine tool operators.