Reciprocal association between atopy and respiratory symptoms in fully employed female, but not male, workers in swine operations.

In large commercial swine operations, workers are exposed to indoor air-contaminants during their work-shift. In recently developed large swine operations, exposures are typically 8 or 12 hours/day and females account for a sizeable proportion of the workers. Implications of enhanced exposures and gender require evaluation. Two hundred and forty male and 134 female swine barn workers and 184 male and 227 female nonfarming rural dwellers (controls) (mean age +/- SD males: 36.2 +/- 11.9; females: 34.9 +/- 10.7) completed respiratory questionnaires. Of these, 348 workers (93.0%) and 401 controls (97.6%) underwent allergy skin prick tests (house dust mite, Alternaria sp., hog, cat, mixed grass). The number of hours worked per day was 8.2 for female workers and 7.7 for male workers. Atopy was present in 38.7% and 29.4% of male and female workers, and 46.9% and 38.3% of male and female controls. There was a 72% reduction in risk for chronic phlegm and 70% reduction in usual phlegm in female workers with atopy in comparison to female controls without atopy. There was a significantly increased risk for chronic and usual phlegm, and chronic and usual cough in male workers with atopy. Female workers with atopy were at increased risk for asthma. These findings, that atopy in exposed female workers may be protective of symptoms suggestive of chronic bronchitis but that atopic female workers may be more susceptible to the development of asthma, suggest that exposures to inhaled substances in the workplace may be mediated differently in male and female workers.