Distribution of particulate matter and ammonia and physicochemical properties of fine particulate matter in a layer house.

High concentrations of particulate matter (PM) and ammonia (NH3) in poultry houses have adverse effects on the health of workers and animals. The present study investigated the distribution of the PM in different size fractions and NH3, as well as analyzing the physicochemical properties of fine particulate matter (PM2.5) in an enclosed layer house. The detection was taken from 5:00 to 21:00 in every 2 h for a 7-d continuous monitoring using a DustTrak II model 8532 aerosol monitor for PM concentrations and a JK40-IV portable gas detector for NH3 concentrations. The concentrations of inhalable particulate matter (PM10), total suspended particles (TSP), and NH3 were significantly higher in the rear of the chicken house compared to the front (P < 0.05). The PM10, TSP, and NH3 concentrations inside the layer house were significantly higher than outside (P < 0.001). The concentrations of PM10 and TSP were both highest at the first feeding time at 7:00. The PM2.5/PM10, PM2.5/TSP, and PM10/TSP concentration ratios at 5:00 were highest with 0.84, 0.62, and 0.74, respectively. Airflow speed showed a significant correlation with other measured microclimatic variables. Organic carbon was the primary constituent of PM2.5 collected from the layer house. It was also observed that mass percentage of elements C and O were both the highest by energy spectrum diagrams of PM2.5. The ultrastructure of PM2.5 revealed that there were mineral particles derived from feed, feces, or the ground and that smoke polymers came from ambient air. In conclusion, air quality was better at the front than at the middle and rear of the layer house. Air quality outside was better than that inside the house. Chicken activities primarily caused the PM10 and TSP concentrations to increase in the chicken house. The main components of PM2.5 in the layer house were organic matter and minerals, which were mostly derived from feed, feces, and ground dust.