The exposure risks associated with pathogens and antibiotic resistance genes in bioaerosol from municipal landfill and surrounding area

Pathogenic microbes with antibiotic resistance can thrive on municipal solid waste as nu-trients and be aerosolized and transported to vicinities during waste disposal processes. However, the characterization of pathogenic bioaerosols and assessment of their expo-sure risks are lacking. Herein, particle size, concentration, activity, antibiotic resistance, and pathogenicity of airborne microorganisms were assessed in different sectors of a typical landfill. Results showed that active sector in downwind direction has the highest bioaerosol level (1234 CFU/m3), while residential area has the highest activity (14.82 mg/L). Botanical deodorizer from mist cannon can effectively remove bioaerosol. Most bioaerosols can be in-haled into respiratory system till bronchi with sizes ranging from 2.1-3.3 and 3.3-4.7 pm. Pathogenic bacteria ( Bacilli, Bacillus , and Burkholderia-Paraburkholderia) and allergenic fungi (Aspergillus, Cladosporium, and Curvularia) prevailed in landfill. Although high abundance of microbial volatile organic compounds (mVOCs) producing bioaerosols were detected, these mVOCs contributed little to odor issues in landfill. Notably, surrounding areas have higher levels of antibiotic-resistance genes (ARGs) than inner landfill with tetC, acrB, acrF, mdtF, and bacA as dominant ones. Most ARGs were significantly correlated with bacterial community, while environmental parameters mainly influenced fungal prevalence. These findings can assist in reducing and preventing respiratory allergy or infection risks in occupational en-vironments relating to waste management. (c) 2022 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.

Automated summary

This study assessed the characteristics and exposure risks of airborne microorganisms in different sectors of a typical landfill. The results showed that active areas during waste disposal processes and the surrounding areas had higher levels of pathogenic microorganisms and allergenic fungi. Additionally, the surrounding areas had higher levels of antibiotic resistance genes. These findings provide guidance for reducing and preventing respiratory allergy or infection risks in occupational environments related to waste management.