A cross-sectional study of exposures, lung function and respiratory symptoms among aluminium cast-house workers.

UNLABELLED: OBJECTIVES To investigate exposures, respiratory symptoms, lung function and exposure-response relationships among aluminium cast-house workers. METHODS: A cross-sectional study was conducted among 182 workers. Exposure data were used to model exposure to irritants. Lung function and questionnaire data on respiratory symptoms were compared to a general population sample and an internal reference group. Blood samples were taken from 156 workers to examine total IgE, eosinophils and sensitisation to common allergens. RESULTS: Average daily mean exposure to inhalable dust, metals, hydrogen fluoride, fluoride salts and sulphur dioxide was relatively low compared to reference values. Airflow patterns in the hall were disturbed regularly and resulted in pot emissions with high concentrations of fluorides. Peak exposures to chlorine gas occurred intermittently due to production process disturbances. Workers reported significantly more respiratory symptoms (continuous trouble with breathing (prevalence ratio (PR) 2.5; 95% CI 1.2 to 5.3), repeated trouble with breathing (PR 1.8; 95% CI 1.1 to 3.0), wheezing (PR 1.4; 95% CI 1.1 to 1.8), asthma attack (ever) (PR 2.8; 95% CI 1.7 to 4.6) and doctor diagnosed asthma (PR 2.6; 95% CI 1.5 to 4.4). Regression analysis showed significantly lower FEV(1) values (-195 ml) and FVC values (-142 ml) compared to a general population sample. Lung function did not differ between groups. CONCLUSION: This epidemiological study suggests cast-house workers in the aluminium industry are exposed to respiratory hazards. Exposure-response relationships could not be demonstrated but this study supports preventive measures in the work environment with a focus on (peak) exposures to irritants.

A cross-sectional study among detergent workers exposed to liquid detergent enzymes.

OBJECTIVES: To investigate sensitisation and respiratory health among workers who produce liquid detergent products and handle liquid detergent enzymes. METHODS: We performed a cross-sectional study among 109 eligible workers of a detergent products plant. 108 were interviewed for respiratory and allergic symptoms and 106 blood samples were taken from them to examine sensitisation to enzymes. Those sensitised to > or = 1 enzymes were referred for clinical evaluation. Workers and representatives were interviewed to characterise exposure qualitatively and estimate exposure semi-quantitatively. Workers were classified into three exposure groups with varying exposure profiles to enzymes, based on frequency, duration, and level of exposure. RESULTS: Workers were exposed to proteases, alpha-amylase, lipase and cellulase. The highest exposures occurred in the mixing area. Liquid spills with concentrated enzyme preparations and leakage of enzymes during weighing, transportation and filling were causing workplace contaminations and subsequently leading to both dermal and inhalation exposure for workers. Workers with the highest exposures reported significantly more work-related symptoms of itching nose (prevalence ratio (PR) = 4.2, 95% CI 1.5 to 12.0) and sneezing (PR = 4.0, 95% CI 1.5 to 10.8) and marginally significant more symptoms of wheezing (PR = 2.9, 95% CI 0.9 to 8.7) compared with the least exposed group. Fifteen workers (14.2%) were sensitised to > or = 1 enzymes. A marginally statistically significant gradient in sensitisation across the exposure categories was found (p = 0.09). There was a clinical case of occupational asthma and two others with probable occupational rhinitis. CONCLUSIONS: Workers exposed to liquid detergent enzymes are at risk of developing sensitisation (14%) and respiratory allergy.