Effective health surveillance for occupational asthma in motor vehicle repair

Diisocyanates are the commonest reported cause of occupational asthma (OA) in the UK. Health surveillance should play an important part in the early detection of disease and the prevention of long-term morbidity.

To assess the efficacy of a UK-wide health surveillance programme provided to the motor vehicle repair industry.

Analysis of respiratory questionnaire and spirometry results during the period 1995-2000 and more detailed assessment of the outcome of cases suggestive of OA between 1998 and 2000.

Approximately 3700 employees underwent health surveillance each year. As a result, a number (27%) required further assessment; information on 92 employees who were referred to their general practitioner (GP) for further assessment was examined. Half of these employees subsequently failed to see their GP and of those referred to a specialist only 63% attended that appointment. Of the 20 employees who did see a specialist, nine (45%) were subsequently diagnosed as having OA due to isocyanates, indicating a mean annual incidence rate of 0.79 per 1000 workers identified by surveillance. A year after identification, five of the diagnosed employees were still working in the same job.

Health surveillance is only one part of a process for identifying OA. In this programme, the high drop out rate of employees in the medical investigation process initiated by surveillance was a significant problem. Recommendations are suggested for the future operation of respiratory health surveillance programmes.