Spatial, diurnal and seasonal variations in the levels of environmental parameters in Australian livestock buildings

Abstract

In order to identify the most suitable, practical and representative sampling sites to undertake reliable air quality and environmental assessments in intensive piggery buildings, the spatial, diurnal and seasonal variations observed in the concentrations of major airborne pollutants (including ammonia, carbon dioxide, and airborne particles) and related environmental parameters (such as airspeed, temperature and humidity) were investigated. Air quality parameters were recorded in a number of piggery buildings over a 2.5-day period. The air quality monitoring equipment used included cyclone attachments to measure particles of less than 5 microns and an SHS (Seven Hole Samplers) attachment to measure inhalable airborne particles, attached to air pumps operated at 1.9 and 2.0 L/min respectively. Ammonia and carbon dioxide were monitored using a Multi-gas Gas Monitoring Machine (MGM) for a number of days on each monitoring occasion. The concentrations of airborne particles were also measured using Osiris optical particle counter (Turnkey technologies, UK) and airspeed were measured using a hot-wired anemometer (Alnor Instruments, Shoreview, Minn.). Interesting patterns in the concentration of carbon dioxide, dust and ammonia were observed over time and space. Carbon dioxide, airspeed and dust concentration demonstrated an obvious circadian pattern. The difference in the concentrations ammonia and carbon dioxide between different sampling sites in the same building was not statistically significant. However, the concentration of inhalable particles was not uniform throughout the buildings and proved to be higher above the walkways when using gravimetric measurements. Ammonia and respirable particle concentrations were significantly higher in summer when compared to winter conditions. The results combined give us a clear picture of the most appropriate sampling times and sampling places for appropriate evaluation of air quality in intensive livestock buildings.