Study objectives: A study was conducted to evaluate the
acute health effects of wearing an N-95 disposable respirator in a
swine confinement facility.
Design: A crossover
trial design was used in the study.
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 barn 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 (intervention day), and a 4-hour exposure in a
traditional swine room without a respirator (nonintervention day).
Measurements: Lung function, methacholine challenge tests,
blood counts, nasal lavage, and cytokines in serum and nasal lavage
Results: Mean (± SE) shift
change in FEV1, from preexposure to postexposure, 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 mean values of the provocative
concentration of a substance (methacholine) causing a 20% fall in
FEV1 (nonintervention day, 130.4 ± 36.9 mg/mL;
intervention 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 levels of IL-6 in serum for the
nonintervention day in comparison to the other 2 days.
Conclusions: The results demonstrate that an N-95
disposable respirator can help to significantly reduce acute
negative health effects in subjects not previously exposed to a swine