Air Quality Assessment and Potential Inhalation Exposure Across Equestrian Facilities: A Case Study

Air quality in equestrian facilities is an important factor affecting equine respiratory health. This study evaluated particulate matter (PM), gaseous pollutants, and microclimatic parameters in a stable, an indoor riding arena, and an outdoor riding arena, and estimated the potential inhaled dust dose in horses under different exposure scenarios. Nine independent measurements were conducted at a height of 1.5 m in three locations. Concentrations of PM1, PM2.5, PM10, respirable dust, total dust, and selected gaseous pollutants were measured. Four exposure scenarios combined 18 or 20 h spent in the stable with 4 or 6 h spent in the indoor or outdoor riding arena. Measurements were performed during summer under normal operating conditions at a university equestrian centre in Slovakia. The outdoor riding arena exhibited the highest concentrations of all PM fractions, whereas the indoor riding arena showed the lowest values (p < 0.05). Ammonia concentrations were higher in the stable than in the indoor riding arena, while the remaining gaseous pollutants showed only minor differences between facilities. Spatial mapping identified localized areas of elevated PM2.5 and PM10 concentrations, and exposure modelling demonstrated higher estimated inhaled mass of total and respirable dust for scenarios involving outdoor training. The results indicate that particulate matter, rather than gaseous pollutants, was the main factor affecting air quality. Reducing dust generation through appropriate riding surface management, regular maintenance, and air quality monitoring may help minimize inhalation exposure and improve the respiratory environment for horses.