In the Pakistani textile industry, the prevalence of workplace respiratory illness, including byssinosis, is high. This study determined the effectiveness of a multifaceted intervention package in reducing dust levels in cotton mills, decreasing the frequency of respiratory symptoms among cotton textile workers, and improving their lung function.
I undertook a cluster-randomised controlled trial at 38 textile mills (n=2031 workers at baseline) in Karachi. The intervention comprised: training in occupational health for workers and managers backed by regular refresher sessions; the formation of workplace committees to draw up, agree and promote a health and safety plan that included wet mopping, safe disposal of cotton dust, and the use of simple face masks, as well as further publicity about the risks from cotton dust; and provision of adequate supplies of face masks to support the health and safety plan. Participating mills were randomised to intervention and control arms following a baseline survey. The impact of the intervention was determined through follow-up surveys conducted at 3, 12 and 18 months. The data collected included spirometry, questionnaire-based interviews, and cotton dust measurements.
At the end of the trial, in the sub-group (n=616; 30%) of workers that never left the study, I found an overall improvement in the composite outcome (57% to 44%), partly attributed to chest tightness; minor decline in lung function (FEV1-predicted: 76% to 75%) and personal dust levels (610 to 525 µg/m3). In the adjusted models (n=807; 40%), workers in the intervention arm were more likely to report an improvement in the composite outcome (OR: 1.58; 95% CI: 1.06-2.37) and lung function (β: 1.31%; 95% CI: 0.04-2.57).
I found the intervention to be effective in improving respiratory health of cotton textile workers. These findings pave the way for scaling-up of such simple and feasible interventions in low- and middle-income countries.