Byssinosis in the cotton waste industry.

A cross-sectional survey was carried out on 772 workers in 27 mills in the North of England involved in the processing of cotton waste. The overall prevalence of byssinosis as defined by Schilling's criteria was 9.8 per cent with 5.4 per cent having grades 2 and 3. The prevalence in workers who had only ever had cotton waste exposure (5 per cent) was significantly less than for those who had mixed waste and raw cotton exposure. There was no clear relationship between prevalence of byssinosis and years of exposure or dust levels.