Positive human health effects of wearing a respirator in a swine barn

Study objectives: A study was conducted to evaluate the acute health effect s of wearing an N-95 disposable respirator in a swine confinement facility. Design: A crossover trial design was used in the study. Setting: The study was carried out at the research facilities of the Centre for Agricultural Medicine, the Royal University Hospital, and the Prairie Swine Centre inc, Saskatoon, Saskatchewan, Canada. Participants: Twenty-one nonsmoking healthy male subjects with no previous swine bent exposure participated in the study. Interventions: The subjects participated in a laboratory session (baseline day), a 4-h exposure in a traditional swine room wearing the respirator (in tervention day), and a 4-hour exposure in a traditional swine room without a respirator (nonintervention day). Measurements: Lung function, methacholine challenge tests, blood counts, na sal lavage, and cytokines in serum and nasal lavage fluid. Results: Mean (+/- SE) shift change in FEV1, from preexposure to postexposu re, was highest on nonintervention day (-8.1+/-1.01%) and was significantly different from intervention day (0.32 +/- 0.62%; p < 0.0001) and baseline day (1.57 +/- 0.51%; p < 0.0001), Similar patterns were observed in the mea n values of the provocative concentration of a substance (methacholine) cau sing a 20% fall in FEV1 (nonintervention day, 130.4 +/- 36.9 mg/mL; interve ntion day, 242.0 +/- 38.0 mg/mL; and baseline day, 328.0 mg/mL +/- 34.1 mg/ mL), Significant increases in serum neutrophil levels and nasal cell counts were observed on the nonintervention day in comparison to the baseline and intervention days. Significant increases also were found in the levels of cytokines interleukin (IL)-6 and IL-8 in nasal lavage fluid and in the leve ls of IL-6 in serum for the nonintervention day in comparison to die other 2 days. Conclusions: The results demonstrate that an N-95 disposable respirator car l help to significantly reduce acute negative health effects in subjects no t previously exposed to a swine barn environment.