REPORTED INCIDENCE OF OCCUPATIONAL ASTHMA IN THE UNITED-KINGDOM, 1989-90

Study objective-To estimate the incidence of occupational asthma seen by respiratory and occupational physicians in the UK in 1989 and 1990. Design-New cases of occupational asthma were taken from a national re porting scheme, the Surveillance of Work-related and Occupational Resp iratory Disease Project (SWORD). Estimates of the working population f rom the Labour Force Survey were used to calculate reported incidence by age group, sex, occupation, and region. Setting-The SWORD project i s a scheme for the reporting of new cases of work-related respiratory disease by thoracic and occupational physicians from throughout the UK which began in 1989. Patients-In 1989 and 1990, of 4229 cases reporte d, 1085 (26%) were in patients with occupational asthma. Main results- Only half the reported cases were attributed to agents prescribed unde r the Industrial Injuries Scheme. There was considerable diversity in risk by occupation, with highest annual rates in welders, solderers, a nd electronic assemblers (175/million), laboratory workers (188/millio n), metal treaters (267/millon), bakers (334/million), plastics worker s (337/million), chemical processors (364/million), and spray painters (658/million). Crude rates in men were higher than in women, but rate s within occupations were similar in both sexes. Rates of disease rose with age; adjustment for occupation increased the gradient. Regional differences were only partly explained by diversity of industry and we re probably mainly due to variation in levels of ascertainment and rep orting. Conclusions-Asthma is the most commonly reported occupational lung disease in the UK. The incidence in the general population is unk nown, but it was estimated that the incidence of new cases seen by res piratory and occupational physicians was about three times that report ed. High relative risks were found in a number of occupations in which effective control of the work environment is urgently required.