Indoor air quality and airborne transmission under the One Health lens: A scoping review

Humans spend around 90 % of their time indoors, making Indoor Air Quality (IAQ) of utmost importance. Its importance has been recently highlighted by COVID-19. However, IAQ significantly impacts public health, concerning not only respiratory, but also cardiovascular diseases. The World Health Organization defines One Health as "an approach to designing and implementing programmes, policies, legislation and research in which multiple sectors communicate and work together to achieve better public health outcomes". This scoping review fills a gap in the literature by exploring the One Health approach, which integrates human, animal, and environmental health, applied to the study of airborne transmission. We searched various databases for articles that assessed microbiological IAQ using the One Health approach. Eligible documents assessed air contamination, with a focus on infectious threats and antimicrobial resistance. Our work maps the topics covered, the methodologies employed, and the evidence gaps identified. Our literature search yielded 8471 articles, from which 18 studies were selected for detailed analysis. Findings indicate that the One Health approach effectively addresses the complex challenge of airborne microbiological contamination. This approach comprises a comprehensive view of topics, contexts, agents and methodologies employed to study airborne transmission in indoor spaces. The agents included range from influenza, legionella and others, to the dispersal of mycotoxins and antibiotic resistance genes. The role of animals in diverse human-animal interaction settings was highlighted as a significant factor influencing IAQ, particularly in relation to zoonotic spillover risks, and the airborne transmission of antimicrobial resistance. The review also identified evidence gaps in research and highlighted the need for interdisciplinary collaboration. Incorporating One Health principles into IAQ research is essential for developing comprehensive health strategies that can address both current and emerging infectious threats. Future research should prioritise settings involving animal-human indoor interactions, focusing on workplace contamination, zoonotic spillover, emergent threats, and the airborne transmission of antimicrobial resistance, to ensure a robust framework for safeguarding global health.