swine production workers are at substantial risk of adverse respiratory outcomes that include increased bronchial inflammation ( Pedersen et al., 1996 Larsson et al., 1994), decreases in forced expiratory volume (FEV 1) across a work shift ( Reynolds et al., 1996), accelerated FEV 1 decline ( Iversen and Dahl, 2000), and bronchial hyperresponsiveness ( Vogelzang et al., 2000). The benefits of readily available technology to significantly reduce concentrations of dust and CO 2 demonstrates useful control options to improve air quality in swine buildings.Īn estimated 200,000 to 500,000 U.S. A 940 ppm reduction in CO 2 was attributed to the use of the vented heater, after accounting for differences in outdoor temperatures and animal housing over both test periods. Carbon dioxide concentrations were significantly lower with vented heaters (mean = 1400 ppm, SD = 330 ppm) compared to unvented heaters (mean = 2480 ppm, SD = 160 ppm). The filtration unit is recommended to improve livestock building air quality because it was more effective than the cyclone unit at reducing respirable dust. The dust concentrations were significantly reduced by the ventilation system for both inhalable dust (23% to 44% with filtration, 33% with cyclone) and respirable dust (32% with filtration, 20% with cyclone), significant (p < 0.024) for all except respirable dust using the cyclone (p = 0.141). Although concentrations of ammonia increased over each winter test period, the increase was unrelated to increased air movement from the new recirculating ventilation system. The concentrations of carbon monoxide and hydrogen sulfide were negligible in the test room. A second treatment evaluated reductions in carbon dioxide (CO 2) associated with replacement of standard, unvented gas-fired heaters with new vented heaters, installed between the two winter test periods. This system incorporated one of two readily available dust control systems, one based on filtration and the other on cyclonic treatment. Over two winters, changes in air quality were evaluated following installation of a 1700 m 3 h −1 (1000 cfm) recirculating ventilation system to provide 5.4 air exchanges per hour. This study examined the effectiveness of engineering controls to reduce contaminant concentrations in a swine farrowing room during winter in the U.S.
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