Unveiling the hidden hazards of smog: health implications and antibiotic resistance in perspective

Smog is a form of pollution composed of smoke and fog. It is one of the major environmental and public health problems in many urban areas around the world. Intriguingly, recent evidences have unveiled the potential link between smog and antimicrobial resistance (AMR). Smog can contribute to AMR through a complex and multifaceted set of mechanisms, including particulate matter (PM) which is found in smog, mediated transport of AMR microorganisms and genes, disruption of the respiratory microbiome, and modulation of host immune responses. Since the PM can lodge deeper in the lungs and harbors antibiotic resistance genes (ARGs), it should be considered that PM contributes to AMR toward the respiratory tract infections and other infections. PM can create conditions conducive to bacterial survival and growth in the respiratory system due to inflammation and immune suppression. PM2. 5 and PM10 have been associated with several respiratory system ailments due to their capability to penetrate inner areas. Moreover, PM can serve as a carrier for ARGs and other microbial components, aiding in their spread. This interaction may accelerate the development and spread of AMR. It is imperative to further unleash the mechanisms adopted by microbial extracellular DNA associated with the PM to envisage the potential health and environmental hazards. eDNA, for example, has been shown to contribute to the diversity and composition of microbiota associated with PM, such as bacteria, fungi, and viruses. This review focuses on PM, ARGs, and microbial eDNA as emerging environmental contaminants. A comprehensive analysis is conducted of the mechanisms and circumstances that contribute to its spread in diverse settings. Considering the current explosive increase in microbial resistance to the antibiotics, this also necessitates uncovering the underpinnings of the smog’s effect on AMR and developing effective strategies for mitigating these deleterious smog effects on health and environment.