Contributions of different livestock production animals to dispersion-modelled ambient ammonia and particulate matter in a livestock-dense area

Ammonia (NH₃) and primary PM10 emitted by livestock production affect health and biodiversity, making their reduction essential. Quantities of emitted NH₃ and PM10 vary across different livestock species, potentially leading to different regional spatial patterns of NH₃ and PM10. This complicates the development of effective mitigation strategies. This study aims to provide insight into how different livestock production animals affect spatial patterns of NH₃ and PM10.

The study area of ∼40 x 50 km2 encompassed a livestock-dense area with ∼2000 farms, several residential clusters and nature parks in the Netherlands. Spatial concentration patterns were predicted for ∼100,000 receptor points on a 100 x 100 m² grid using a dispersion model based on farm emissions. Model assumptions were evaluated through sensitivity analyses.

Livestock production emissions significantly increased local levels of NH₃ and more moderately elevated local levels of PM10. Spatial concentration patterns were strongly driven by geospatial distributions of farms as well as livestock species, with elevated concentrations observed in areas where farms were densely clustered. The distribution of farm contributions to total NH₃ concentrations at receptor points was characterized by numerous small contributions from multiple farms across the study area. Concentrations were higher in rural parts of the study area and characterized by the combination of these small contributions with a few large contributions from nearby farms. Inclusion of farms in a wide radius was especially important for modelling NH₃ concentrations in nature areas. These findings imply that generic reduction of livestock farm emissions should be investigated for the formulation of mitigation strategies.