Sweeper’s lung disease: a cross-sectional study of an overlooked illness among sweepers of Pakistan

BACKGROUND: Sweepers are prone to develop chronic obstructive pulmonary disease even without tobacco smoking. PURPOSE: To investigate roadside dust as a cause of air flow obstruction among sweepers, and the role of spirometry in its preclinical diagnosis. MATERIAL AND METHODS: One-hundred nonsmoking sweepers (aged 30–60 years) of both sexes sweeping on roads for 8–12 hours a day for the Capital Development Authority of Islamabad, Pakistan were used as study participants (Group A). One-hundred healthy nonsmokers (aged 30–60 years) in the same socioeconomic group and living in the same environment represented the nonsweeper group (Group B). After proper clinical evaluation and chest X-rays, spirometric evaluation was carried out in both groups. Comparisons were drawn between various spirometric parameters. RESULTS: Pulmonary function tests showed that the mean forced vital capacity was 78 ± 1.40 in the sweeper group (Group A) and 83 ± 0.86 in the nonsweeper group (Group B). Mean forced expiratory volume in 1 second was 66 ± 1.67 in Group A and 85 ± 0.85 in Group B (P < 0.05), a difference of 19%. The forced midexpiratory flow was 41% lower in Group A than in Group B (P < 0.0001). The pattern of pulmonary function obstruction was shown to be proportional to the duration of exposure to dust caused by sweeping. CONCLUSION: Occupational exposure to dust leads to an obstructive pattern among sweepers. Spirometry is the simplest, noninvasive technique to detect preclinical disease.