A comparative assessment of subchronic inhalation health risks between peracetic acid and chlorine dioxide in SPF pigs maintained in barrier environments

BACKGROUND: Barrier environments are essential for maintaining specific pathogen-free (SPF) animals, yet the potential health risks associated with routine aerosol disinfection remain unclear. This study aimed to systematically evaluate the subchronic effects of peracetic acid (PAA) and chlorine dioxide (ClO₂) in SPF pigs maintained under barrier conditions. RESULTS: Both disinfectants achieved > 99.9% elimination of indicator microorganisms under optimized aerosolization protocols. However, distinct biological effects were observed. ClO₂ predominantly affected systemic homeostasis, as reflected by alterations in hematological and biochemical parameters, whereas PAA exerted stronger localized effects on the respiratory system, including functional changes, tissue remodeling, and enhanced inflammatory responses. Additionally, both disinfectants induced structural remodeling of the respiratory microbiota, marked by a decline in Actinobacteriota and an enrichment of opportunistic taxa such as Burkholderiales in the ClO₂ group and Subdoligranulum in the PAA group. Notably, these effects remained subclinical and did not impair growth performance or overt health status. CONCLUSIONS: These findings highlight the distinct subchronic health risk profiles associated with aerosolized disinfectant exposure and provide a scientific basis for optimizing disinfection protocols in SPF pig barrier facilities.