Byssinosis in ginning factories of rural Sindh.

Frequency of byssinosis in 276 workers from 5 ginning factories of rural Sindh are described. Twenty-four (9%) had byssinosis, 178 were asymptomatic and the remaining 74 had other respiratory symptoms. Chronic obstructive pulmonary disease was present both in symptomatic and asymptomatic workers and was equally distributed amongst smokers and non-smokers. A possible involvement of some factors other than cigarette smoking is discussed.