Nuclear anomalies in exfoliated buccal cells in Pakistani cotton weavers

Cotton workers in small weaving household factories (power looms) in Pakistan are typically exposed to high levels of cotton dusts. Working in the textile manufacturing industry has been classified as a possible human carcinogen (group 2B) by the International Agency for Research on Cancer. The study set out to determine potential cytotoxic and genotoxic effects of occupational exposure to cotton dusts in exfoliated buccal cells of exposed cotton workers. Nuclear anomalies reflecting cytotoxic and genotoxic effects were evaluated in a representative sample of 51 exposed male cotton weavers and in the same number of age-matched male non-exposed subjects applying the micronucleus cytome assay. Nuclear anomalies reflecting cytotoxicity (karyolysis, karyorrhexis, condensed chromatin and pyknosis) were significantly elevated in exposed cotton workers. The frequency of micronucleated cells increased significantly with increasing years of work in power looms (odds ratio = 1.043 per year; 95% confidence interval: 1.012-1.076, P = 0.007). Results were consistent with the typical inflammatory pattern and injury in epithelia due to unprotected occupational exposure to cotton dusts and other toxic, allergic and infectious substances in the working areas of the cotton industry. Occupational exposure in power looms induces cytotoxic effects and, upon chronic exposure, DNA damage. This may eventually result in typical obstructive patterns of pulmonary symptoms and in a clinical condition called byssinosis in exposed cotton workers. Long exposure may lead to chronic inflammation and cumulative damage of DNA in buccal stem cells that may indicate an increased risk of oropharyngeal cancer.