The national air emissions monitoring study's southeast layer site: Part V. hydrogen sulfide and volatile organic compounds

Abstract

Aerial pollutants generated from intensive poultry and livestock production raise concerns of health and welfare for the surrounding communities. This article reports emission rates of hydrogen sulfide (H2S) and concentrations of volatile organic compounds (VOCs) from two tunnel-ventilated high-rise houses at a layer site in North Carolina that were tested by the National Air Emissions Monitoring Study (NAEMS). Hydrogen sulfide concentrations exhibited significant seasonal and diurnal variations. The minimum and maximum average hourly mean (AHM) concentrations by hour of day occurred at 15: 00-16: 00 and 6: 00-7: 00, respectively. The lowest and highest daily mean concentrations during the annual cycle were observed in summer and winter, respectively. The AHM H2S concentrations were 1.04 +/- 0.83 ppb for inlet air and 9.52 +/- 6.35 and 9.43 +/- 6.01 ppb, respectively, for exhaust air from the two production houses. The diurnal and seasonal patterns of H2S emission rates from the two production houses were also similar. Slight increases in H2S emission rates occurred at 12: 00 to 14: 00. Higher H2S emission rates occurred in summer. The AHM hen-specific H2S emission rates from the two production houses were 618 +/- 517 and 698 +/- 620 mu g d(-1) hen(-1), respectively. Factors significantly affecting H2S emissions were hen activity, house exhaust air temperature, and ambient air temperature. Time-integrated samples of VOCs were collected over 24 h periods seven times in one production house from 12 April 2009 to 18 September 2009. Of 77 target compounds, the ten most abundant compounds were 2-butanone, iso-propanol, dimethyl sulfide, hexanal, acetic acid, 2,3-butanedione, pentane, acetaldehyde, pentanal, and phenol. Differences in VOC concentrations were observed between the layer room and the manure pit. The highest total VOC concentration was detected in samples taken from the manure pit exhaust air.