Association of environmental air contaminants with disease and productivity in swine.

A cross-sectional epidemiologic study associating air quality with swine health was conducted on 28 swine farms in southern Sweden. Correlation of housing air environment to swine diseases and productivity (data collected over the preceding 12 months) were investigated. The most prevalent swine health problems detected at slaughter were pneumonia and pleuritis. In farrowing and nursery operations, the most prevalent problem was neonatal pig mortality. Several air contaminants (dust, ammonia carbon dioxide, and microbes) were found to be correlated with these swine health problems. Maximal safe concentrations of air contaminants were estimated on the basis of dose-response correlation to swine health or human health problems. Recommended maximal concentrations of contaminant were: dust, 2.4 mg/m3; ammonia, 7 ppm; endotoxin, 0.08 mg/m3; total microbes, 10(5) colony-forming units/m3; and carbon dioxide, 1,540 ppm. The overall quality of the ventilation system was correlated with lower concentration of ammonia, carbon dioxide, microorganisms, and endotoxin, but not with dust concentrations. High animal density was related to high ammonia and air microbe concentrations. Animal density measured as kilograms of swine per cubic meter (compared with kilograms of pig weight or swine per square meter) had the highest correlation to animal health and air contaminants.