Distribution of particle and gas concentrations in Swine gestation confined animal feeding operations.
OBJECTIVE
Dust mass concentrations, temperatures, and carbon dioxide concentrations were mapped in a modern, 1048-pen swine gestation barn in winter, spring, and summer.


METHODS
In each season, two technicians measured respirable mass concentrations with an aerosol photometer and temperatures and carbon dioxide concentrations with an indoor air quality monitor at 60 positions in the barn. Stationary photometers were also deployed to measure mass concentrations during mapping at five fixed locations.


RESULTS
In winter when building ventilation rates were low (center-barn mean air velocity=0.34 m s(-1), 68 fpm) to conserve heat within the barn, mass and carbon dioxide concentrations were highest (mass geometric mean, GM=0.50 mg m(-3); CO2 GM=2060 ppm) and fairly uniform over space (mass geometric standard deviation, GSD=1.48; CO2 GSD=1.24). Concentrations were lowest in summer (mass GM=0.13 mg m(-3); CO2 GM=610 ppm) when ventilation rates were high (center-barn mean air velocity=0.99 m s(-1), 196 fpm) to provide cooling. Spatial gradients were greatest in spring (mass GSD=2.11; CO2 GSD=1.50) with low concentrations observed near the building intake, increasing to higher concentrations at the building exhaust.


CONCLUSIONS
Mass concentrations obtained in mapping were generally consistent with those obtained from stationary monitors. A moderately strong linear relationship (R2=0.60) was observed between the log of photometer-measured mass concentration and the log of carbon dioxide concentration, suggesting that carbon dioxide may be an inexpensive alternative to assessing air quality in a swine barn. These results indicate that ventilation can effectively reduce contaminant levels in addition to controlling temperature.
The University of Iowa, Occupational and Environmental Health Iowa City, IA, USA. thomas-m-peters@uiowa.edu
Thomas M
TM
Peters
T Renée
TR
Anthony
Craig
C
Taylor
Ralph
R
Altmaier
Kimberley
K
Anderson
Patrick T
PT
O'Shaughnessy
D000383:Agriculture; D000395:Air Pollutants, Occupational / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis; D000821:Animal Feed / Q000009:adverse effects*; D000822:Animal Husbandry / Q000379:methods; D000818:Animals; D002245:Carbon Dioxide / Q000032:analysis; D004391:Dust / Q000032:analysis; D005260:Female; D006801:Humans; D012621:Seasons; D013552:Swine; D014691:Ventilation / Q000379:methods
D000395:Air Pollutants, Occupational; D004391:Dust; D002245:Carbon Dioxide