Characteristics of ammonia, hydrogen sulfide, carbon dioxide, and participate matter concentrations in high-rise and manure-belt layer hen houses

摘要

Indoor air pollutants at high concentrations in poultry houses can potentially affect workers' health, and animal welfare and productivity. This paper presents research results of a 2-year continuous monitoring of ammonia (NH3), carbon dioxide (CO_2), hydrogen sulfide (H_2S), and paniculate matter (PM) concentrations from to date the most comprehensive study on a single farm in two 180,000-bird high-rise (HR) and two 200,000-bird manure-belt (MB) layer hen houses located in Indiana, USA. Air was sampled at ventilation fans of the mechanically-ventilated houses. Concentrations of NH3 and CO_2 were measured with photoacoustic multi-gas monitors. Concentrations of H_2S and PM_(10) were monitored with pulsed fluorescence analyzers and Tapered Element Oscillating Microbalances (TEOM), respectively. The 2-year mean ± standard deviation concentrations at ventilation fans of the four layer hen houses were 48.9 ± 39 and 51.9 ± 40.7 ppm in HR, and 13.3 ± 9.1 and 12.9 ± 10.5 ppm in MB for NH3; 26.4 ± 17.6 and 24.9 ± 19 ppb in HR, 40.0 ± 21.1 and 41.2 ± 31.5 ppb in MB for H_2S; 1755 ± 848 and 1804 ± 887 ppm in HR, and 2295 ± 871 and 2285 ± 946 ppm in MB for CO_2; and 540 ± 303 and 552 ± 338 μg m~(-3) in HR, and 415 ± 428 and 761 ± 661 ug m~(-3) in MB for PMin. Compared with the MB houses, concentrations of the HR houses were higher for NH3, and lower for CO_2, H2S, and PM10 (P < 0.05). High concentrations of NH3 detected in winter represent potential challenges to workers' health and animal welfare. Variations in pollutant concentrations at the exhaust fans were affected by outdoor temperature, ventilation, bird condition, and farm operation. A new weekly variation, characterized by significantly lower PM_(10) concentrations on Sundays, was identified and was related to the weekly schedule of house operational activities.