Occupational Asthma in Foundry Workers

A study was carried out of 911 men in 10 ferrous foundries in England. The 509 men exposed to chemical binders in core and mould work were more likely to complain of chest tightness (16.1%) that was worse on working days than the 402 non-exposed men (7.7%) from the comparison group; an odds ratio of 2.32 (95% confidence interval 1.50–3.61) was found for chest tightness having allowed for confounders. Of the 170 exposed men complaining of at least one work-related symptom, 144 underwent histamine challenge testing; 20 (3.9% of exposed men) were positive. In the non-exposed group only eight (2.0% of the unexposed group) were positive. No difference was seen between exposure groups in the small number of cases diagnosed as occupational asthma. Exposures to isocyanates and amines were below detection levels in all foundries but aldehydes were detected in two and furfuryl alcohol in six. Tracing of ex-employees was difficult, but gave no evidence of major differences in health between those who had left exposed or other jobs. Although there was only weak evidence of respiratory ill health associated with foundry work in this study, the potential exists where exposures to chemical binders are high.