Occupational respiratory disease is the name for a collection of conditions of the respiratory system which can have occupational factors as risk factors for the particular disease. This includes acute, sub-acute and chronic diseases, which may be malignant, non-malignant or in infectious origin. However, many of these conditions can be caused by non-occupational factors, so deciding whether a particular type of respiratory disease should be considered as work-related is not always clear. In particular, this is often a problem in recognizing the work association for those conditions which are common in the community, e.g. asthma, or have a long latent period between work exposure and the development of the disease. In such situations, the relationship to work is often not recognised.
92% of the reported cases in Belgium included occupational asthma of an immunological type and 8% bronchial irritability. According to the opinion of the reporting physicians the diagnosis was considered certain in 39%, probable in 29% and possible in 32% of cases. On the basis of these notifications the mean annual incidence of occupational asthma is estimated as 23.5 cases per million workers (95% confidence interval 19.2-28.8). At the time of diagnosis 38% of patients had not applied for compensation. As occupational respiratory diseases can be difficult to identify and control, their prevention is likely to be more effective by implementing complementary actions such as education towards employers, workers, and physicians, research in order to identify new hazards