RESUMEN
BACKGROUND: Workers in cotton industry are occupationally exposed to various dust-related hazards. The nature of these agents and the respective exposure levels depend on the cotton industry specific sector. These exposures could be associated with respiratory symptoms and changes in lung function parameters. OBJECTIVE: To evaluate associations between occupational exposure and respiratory function as well as reported symptoms in several groups of workers at different stages of the cotton industry in a vertical approach that covers all the major sectors-from cotton ginning to weaving and fabric production. METHODS: A questionnaire on respiratory symptoms and individual as well as workplace characteristics was completed by 256 workers at the cotton industry and 148 office workers (control group). Both groups underwent spirometry. RESULTS: Workers in cotton industry reported a higher prevalence of severe dyspnea (p=0.002) and wheezing (p=0.004) compared to the control group. Also they were found to have a lower predicted FEV1% (p<0.029) and lower FEV1/FVC (p<0.001) values. In addition, a higher prevalence of FEV1% <80% (p<0.001) and FEV1/FVC <70% (p=0.041) were found among textile workers. Similar results were found for non-smoker textile workers compared to non-smoker control group workers. Those working in cotton ginning mills recorded the highest decrease of spirometric values. Duration of employment in cotton industry and smoking use were found to be predictors of lung function decline for cotton industry workers. CONCLUSION: Occupational exposure to cotton dust was associated with increased prevalence of respiratory symptoms and obstructive pattern in pulmonary function test.
