A respiratory epidemiological study of stevedores intermittently exposed to asbestos in a South African port.

The prevalence of asbestosis in stevedores intermittently transporting crocidolite asbestos in a South African port was found to be 30% in a cross-sectional survey. Diagnostic criteria are discussed in terms of the low index of suspicion for industrial diseases, the high probability of missing slight radiological changes, and the attribution of radiological lesions to other diseases, particularly tuberculosis, in a high prevalence area. Results are compared with other studies. Asbestosis was not associated with tuberculosis. Smoking was not significantly associated with asbestosis, other respiratory signs and symptoms, or radiological abnormality.