Concentration and particle size distribution of particulate matter inside tunnel-ventilated high-rise layer operation houses

Particulate matter (PM) is a criteria pollutant emitted from animal feeding operation (AFO) facilities, especially from poultry operation buildings. Fundamental data regarding AFO PM either do not exist, or are not representative of different animal production systems or housing types. This field study investigated particle size distributions (PSDs) and concentrations of total suspended particulate (TSP) in a tunnel ventilated high-rise layer house under different operational conditions. Six low-volume (1 m3 h−1) TSP samplers were used to collect PM samples on two floors of the high-rise layer houses across four seasons through day/night sampling protocols. The day/night sampling design was to examine animal activity impact. The PM samples were analyzed by a multi-wave length laser diffraction particle size analyzer (LS13 320) for PSDs characterized by mass median diameters (MMDs) and geometric standard deviations (GSDs). It was discovered that the mean TSP concentrations ranged from 1.0 ± 0.5 mg m−3 to 5.33 ± 0.36 mg m−3 (mean ± SD). TSP concentrations in winter were higher than in summer; concentrations on the 2nd floor were higher than that on the 1st floor; concentrations of daytime samples were higher than those of nighttime samples. Animal activity (represented by day/night samples) had the highest impact on TSP concentration as compared to other influential factors (spatial, seasonal, ventilation). No significant seasonal variations of MMD and GSD were observed in most of samples. Majority of day/night MMDs and GSDs demonstrated no significant differences. Thus the impact of animal activity (day vs. night) on MMD and GSD were not significant. Mean MMDs ± SDs ranged from 16.81 ± 1.57 μm to 20.26 ± 3.53 μm, whereas means ± SDs of GSDs ranged from 2.38 ± 0.20 to 2.81 ± 0.30. Mean PM2.5 fractions ± SDs ranged from 5.03 ± 1.60% to 8.93 ± 0.97%, whereas mean PM10 fractions ± SDs ranged from 23.25 ± 5.18% to 38.55 ± 2.96%. Significant seasonal variation in both PM10 and PM2.5 mass fractions were observed.