Evaluation of a gravimetrical method with a cyclonic pre-separator against the reference method for measuring high PM10 mass concentrations in livestock houses

PM₁₀ emission from livestock houses is a major contributor to the ambient PM₁₀ mass concentrations in many industrialized countries. Measurement methods developed for stationary source PM₁₀ emissions (e.g., EN 13284) are often unsuitable for application in livestock houses whereas methods for ambient air based on impaction pre-separators (e.g., EN 12341) are vulnerable to particle bouncing and overloading. In the past, a gravimetric reference method of EN 12341 (IPS) has been modified by incorporating a cyclone as pre-separator (CPS).

The aim of this study was to investigate the equivalence of the modified version of the reference method used in livestock houses. Previous studies comparing the CPS and IPS reported a high variation in the relationship between these two samplers. This study examines the effect of different livestock categories on this relationship, as differences in particle size distributions associated with different livestock categories, are expected to influence the relationship between these two methods. Both CPS and IPS were applied in this study across multiple livestock houses of 3 livestock categories (fattening pigs, laying hens, broilers). Additionally, a meta-analysis was conducted, incorporating data from previous studies on gravimetric measurements of PM₁₀, to establish a calibration function for measurements obtained using the CPS.

This study concludes that the observed performance of the CPS is higher than the IPS in terms of between sampler uncertainty. Furthermore, the relationship between PM₁₀ measurements with the IPS and CPS has been shown to be different for different livestock categories. The accuracy of CPS measurements relative to IPS measurements improves significantly when livestock category-specific calibration functions are applied, rather than using generic calibration functions. The necessity for livestock category-specific calibration of the CPS in relation to the IPS is also supported by the results of the meta-analysis.