Background: Among the different occupational hazards to which cotton industry workers are exposed such as accidents, fire, disabilities, noise and heat, of all, the largest health hazard is due to inhalation of cotton dust. Prolonged cotton dust inhalation causes various known diseases in textile industry such as byssinosis and chronic obstructive pulmonary disease. These disorders seems at least partly, be mediated by oxidative stress and altered immune system. Objective: To assess oxidative stress and immunoglobulin levels (IgG & IgM) in workers exposed to cotton dust. Setting: This
study was conducted in Misr Helwan Industry for Spinning and Weaving on cotton dust exposed workers in the spinning department. Subjects and methods: Forty two workers exposed to cotton dust were included in this study together with 30 non exposed apparently healthy subjects taken as controls. Every participant of this study was subjected to occupational history taking, detailed questionnaire, thorough clinical examination, assessment of serum malondialdehyde (MDA), nitric oxide, superoxide dismutase (SOD), glutathione peroxidase, catalase, and total antioxidant status, and
measuring of immunoglobulin levels (IgM & IgG). Both groups were matched as regards age, sex, smoking habit, duration of employment and socioeconomic status. Results: The levels of oxidants biomarkers (nitric oxide and MDA) were significantly elevated, and antioxidants (glutathione peroxidase, catalase, SOD and total antioxidant)
were significantly decreased in exposed workers compared with the controls. Statistically significant increase in the immunoglobulin levels was observed in cotton exposed workers (vs. controls). No significant difference was found in oxidant /  antioxidant status and immunoglobulin levels between exposed smokers and exposed non-smokers. Smoker exposed workers showed statistically significant elevation in their levels of oxidant biomarkers (MDA & nitric oxide) and immunoglobulin M when compared to those in controls. Age and duration of employment in exposed workers were significantly negatively correlated with total antioxidant status while no significant correlation was found with other antioxidants nor with oxidant parameters. Conclusion: Workers exposed to cotton dust were under great oxidative stress as manifested by a rise in oxidant biomarkers and a reduction in antioxidants. Cotton dust stimulates humoral immunity as detected by the increases in the immunoglobulin levels. Smoking may have synergistic effect with cotton dust in induction of oxidative stress. These bio-functional markers might be useful in screening and surveillance for occupational hazard.