Effects and health risk assessments of different spray disinfectants on microbial aerosols in chicken houses.

This study aims to explore the effects of spray processes with four different disinfectants on airborne culturable and pathogenic microbial concentrations, microbial community compositions and health risk assessments in chicken houses. Results indicate that compared to the microbial concentrations before spraying, hypochlorous acid, glutaraldehyde-decamethonium bromide and sodium dichloroisocyanate increase culturable bacteria, culturable fungi, airborne Staphylococcus and Candida albicans, respectively. Beyond that, the spray processes with different disinfectants have no significant effects on the microbial concentrations. The total relative abundances (RAs) of the screened out 46 pathogenic bacterial genera decrease after spraying with povidone iodine, while increase after spraying with the other three disinfectants, which is opposite for the 35 pathogenic fungal genera. The core bacterial or fungal genera principally interrelate with each other through cooperation. Ammonia (NH3) concentrations, relative humidity (RH) and temperature (T) influence bacterial communities in aerosols; while fungal communities are mainly affected by T, particulate matters and nitrous oxide (N2O) concentrations. Long-term exposure to aerosols in chicken houses have potential adverse effects on human health and the spray processes with different disinfectants exacerbate the health risks of aerosols via inhalation. Hence, different spray disinfectants cannot significantly reduce the microbial aerosols in real chicken farm environments and the cleaning procedures should be comprehensively reviewed and optimized in livestock and poultry farms.