Investigation of NH ₃ Concentrations around Livestock Farms in Balıkesir and Bursa

Abstract. Ammonia (NH3) is both an air pollutant and a contributor to particulate matter, which has significant effects on human health. The main source of NH3 is agriculture, especially livestock farming. This study evaluated NH3 levels in Balıkesir and Bursa for 2019–2023 via IASI retrievals, EMEP emission inventory, livestock production statistics, and meteorological data. Results showed that NH3 concentrations were lowest in 2019 and highest in 2023. A clear seasonal profile was observed, with maximum levels in summer and minimum in winter, except for autumn 2023, which unusually became the second highest season. Concentrations in Balıkesir were more consistent with the emission inventory with higher correlations (r= 0.82) compared to Bursa (r= 0.48). Districts with both high NH3 levels and intensive livestock activities, such as Altıeylül, Karacabey, and Mustafakemalpaşa, were examined at the farm scale. According to result, some farms appeared to be potential NH3 sources, while for others additional local factors may also have contributed. Wind rose analyses suggested that northerly and northeasterly winds often influenced the transport of NH3 pollution. The study indicated that NH3 levels in Balıkesir and Bursa are closely associated with livestock activity, but also strongly depend on meteorological factors. The study showed the value of combining satellite data, emission inventories, and livestock statistics to better understand NH3 pollution in agricultural regions, while highlighting the importance of farm-scale assessments for evaluating the role of agricultural point sources in local air quality.