PM10 and greenhouse gases yearly emission factors measured in four different pig weaning rooms

Aerial pollutants emitted by intensive livestock production consist mainly of bioaerosols and gases. Bioaerosols are a complex mixture of organic dust, biologically active components and microorganisms that may affect the well-being and the health of humans and animals. The most important greenhouse gases (GHG) generated by animal facilities are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). The aim of this study was to quantify the concentration and emission levels of PM10 and greenhouse gases emitted from four different mechanically ventilated pig weaning rooms during one year of observation, considering three production cycles per each room. The PM10 and GHG measurements were performed in four weaning rooms (R) in three commercial pig houses located in Northern Italy. All rooms had a slatted floor but differed for manure removal system (R1 and R2 were BAT solutions with a vacuum system, R3 and R4 were traditional or reference systems), feeding type and ventilation systems. PM10 concentration was continuously monitored by a sampler (HAZ DUST- EPAM 5000) combining “near- forward light scattering” with the traditional gravimetric technique performed to adjust the particulate matter specific gravity of bioaerosol that is typical and specific for every animal house. GHG concentrations were measured every 15 minutes in the exhaust ducts using an infrared photoacustic detector IPD (Brüel & Kjaer, Multi-gas Monitor Type 1302, Multipoint Sampler and Doser Type 1303). CO2 concentration in the incoming outdoor air was obtained for each room in six independent measurements for each of the three periods during the one year experiment. Emission rate was calculated as the multiplication of pollutant concentration with the ventilation rate recorded in the same minute. PM10 yearly and CO2 emission rates were mainly affected by high ventilation rate and low humidity. The PM10 yearly emission factor ranged from 0.2 (R1) to 2.7 g d-1 LU-1 (R2), the yearly emission factor for CO2 ranged from 3556 (R3) to 5997 g d-1 LU-1 (R1), yearly emission factor for CH4 ranged from 24.57 (R1) to 77.14 g d-1 LU-1 in R4; the yearly emission factor for N2O ranged from 2.29 in R4 to 3.62 g d-1 LU-1 in R1. The analysis revealed a strong dependence of PM10 and GHG concentration on the climate controller and confirmed the variability in the emission inventory of particulate matter and GHG.