Unveiling the Microbial Symphony: Exploring Emerging Contaminants in Zoological Environments for Enhanced Animal Welfare

The quantification of bioaerosols and particulate matter within zoo enclosures is a critical yet underexplored area, particularly given the global role of zoological environments in wildlife conservation, research, and public education. Zoos, which host a diverse array of wildlife and attract millions of visitors annually, are complex ecosystems where multiple sources of air pollution converge. This study aimed to systematically assess the prevalence of bacterial aerosols within various animal enclosures, including those of Tigers, Lions, Leopards, Rheas, Deer, Hippos, Ostriches, Crocodiles, and Owls. Utilizing a six-stage Andersen impactor, bioaerosol samples were collected to determine the concentration and dispersion of airborne microorganisms, while the DustTrak Aerosol Monitor was employed to measure levels of particulate matter (PM10, PM2.5, and PM1), carbon dioxide (CO2), and formaldehyde (HCHO). The findings revealed distinct bacterial population peaks across different locations and animal species, highlighting significant variations in airborne bacterial levels within the sampled enclosures. Gram staining identified a predominance of Gram-negative bacteria, which poses broader implications for understanding the transmission of pathogens and antibiotic resistance in confined environments. Notably, this study provides a foundational framework for evaluating bacterial resistance to antibiotics in zoological settings, contributing to the global discourse on antimicrobial resistance (AMR). The insights gained underscore the necessity of judicious antibiotic use to safeguard both animal health and broader public health. Given that animals are substantial generators of bioaerosols, this research emphasizes the importance of stringent maintenance of enclosures and their surroundings, alongside the optimization of microclimatic conditions to mitigate health risks. By shedding light on the microbial dynamics in zoo environments, this study calls for proactive, globally informed measures to ensure the welfare of animals and the health of visitors, thus advancing the broader understanding of bioaerosol management in complex, human-animal interaction spaces.