城市生活垃圾处理链耐药基因的流行状况及风险分析

Objective To understand the temporal and spatial distribution of antibiotic resistance genes (ARGs), respiratory exposure risks, and diffusion predictions within a municipal solid waste treatment chain in Shanghai, in order to provide a reference for ensuring the public health safety of the municipal solid waste treatment chain. Methods The PM10 (n=47) and related environmental samples (n=41) collected from a municipal solid waste treatment chain in Shanghai from December 2021 to January 2023 were analyzed by metagenome sequencing. The average daily exposure dose of ARGs was used to assess respiratory exposure risk, and the diffusion of airborne ARGs was predicted by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. Results The most frequently ARGs detected in the air in summer and winter were multidrug-resistant types (57.86%), such as mexT. The relative abundance of total ARG subtypes in the air in summer ranged from 1.03±0.66 copies/m³ to 2.38±1.45 copies/m³, mainly originating from kitchen waste (16.22%-46.62%). Temperature and pressure were the main influencing factors of ARGs in the air in summer (R²=0.81) and winter (R²=0.83), respectively. The average daily exposure doses of ARGs showed a higher respiratory exposure risk in summer (0.10 copies/(kg·d)) compared to winter (0.04 copies/(kg·d)), especially in office buildings. Streptococcus was a potential host of ARGs (bacA) in summer. The diffusion range of airborne ARGs was larger in summer (112.22 km²) than in winter (82.71 km²). Conclusions Compared with winter, the relative abundance and diversity of airborne ARGs in summer were higher, with Streptococcus being the potential host of ARGs. The respiratory exposure risk in the office building was the highest, mainly originating from the original waste. The diffusion range and direction of ARGs pose a greater risk spread of ARGs. This study provides data support for ensuring the public health safety of municipal solid waste treatment chains.