A study of the prevalence of ventilatory obstruction in textile workers exposed to cotton dust

A study was conducted in a cotton spinning mill to assess the prevalence of respiratory impairment in 189 asymptomatic workers and 133 byssinotics drawn from various sections of the plant exposed to airborne cotton dust in the work environment. Eight-four healthy controls belonging to the same socioeconomic status and ethnic group having never been exposed to cotton dust or any other pollutant was also studied for the purpose of comparison. Of the 189 asymptomatic workers, 13 (6.8%) suffered from bronchial obstruction whereas only 2 (2.3%) among the control showed obstructive pulmonary impairment. The byssinotics showed a significantly higher prevalence (15.7%) of bronchial obstruction than that (6.8%) observed among the asymptomatic cotton workers (P less than 0.005). Byssinotics (grade II) showed significantly higher prevalence (31.5%) of bronchial obstruction than that (9.4%) observed in acute byssinotics (grade I). The effect of smoking on the prevalence of bronchial obstruction in the asymptomatic and byssinotics was quite discernible as smokers showed significantly higher prevalence than that observed among the nonsmokers (P less than 0.05). The asymptomatic cotton workers and those with different grades of byssinosis having more than 10 years of exposure showed significantly higher prevalence of bronchial obstruction than that observed in the group with less than 10 years of exposure (P less than 0.005). The healthy cotton workers and byssinotics engaged in the preparatory section (card, blow, and waste plant rooms) showed an insignificant higher prevalence of bronchial obstruction (11.3 and 24.4%, respectively) than among those who worked in the spinning, reeling, and winding sections of the mill. The mechanism responsible for causing ventilatory obstruction in the textile workers is discussed.