OCCUPATIONAL ASTHMA CAUSED BY AUTOMATED SALMON PROCESSING

Within 3 months of the opening of a salmon-processing plant in the UK, some workers complained of symptoms suggestive of occupational asthma . A survey of all 291 employees identified 24 (8.2%) with occupational asthma. The employees worked near machines which generated respirable aerosols containing salmon-serum proteins. The IgE response to these proteins was associated with occupational asthma (p<0.001), with incre asing severity of symptoms (p<0.001), and with working distance from t he aerosol source (p=0.037). The main factor which predisposed to IgE- antibody production and asthma was cigarette smoking (p<0.001), wherea s atopy and a previous allergic history did not. The affected employee s were reallocated to a low-exposure worksite and factory ventilation was improved. Eleven showed significant clinical and pulmonary functio n improvement, and continued in employment. Thirteen who still had sym ptoms were advised to leave, thereafter becoming symptom-free, and reg aining normal respiratory function. Early recognition of symptoms and prompt action to reduce aerosol exposure avoided the long-term reducti on in pulmonary functions often associated with occupational asthma.