摘要

    垃圾填埋和焚烧是城市固体废物 (MSW) 的主要处理方式，被认为是抗生素抗性基因 (ARG) 的关键储存库。然而，ARGs 从城市固体废物处理系统（MSWT 系统）到环境空气的可能传播仍不清楚。在本研究中，我们收集了 MSWT 系统中的内部和环境空气样本（PM10 和 PM2.5）以及潜在源样本（渗滤液和固体废物）。结果表明，MSWT 系统有助于增加环境空气中的细菌和相关的 ARG。分离出 41 种携带 blaTEM-1 的耐抗生素细菌 (ARB)，空气（下风样本）中 blaTEM-1 基因（由相同芽孢杆菌携带）的全长核苷酸序列与空气中的 blaTEM-1 基因全长核苷酸序列 100% 相同。渗滤液和固体废物，表明 MSWT 系统是环境空气中散布细菌和相关 ARG 的重要来源。通过 PM 吸入的 ARG 的每日摄入 (DI) 负担水平与通过摄入饮用水的水平相当，但低于通过摄入生蔬菜的 DI 水平。从空气中分离出耐抗生素的机会性病原体蜡样芽孢杆菌，在 MSWT 系统中通过吸入（104-106 份/天）的芽孢杆菌具有相对较高的 DI 水平。这项研究突出了空气中 ARG 对人体暴露的关键途径。

    Landfill and incineration are the primary disposal practices for municipal solid waste (MSW) and have been considered as the critical reservoir of antibiotic resistance genes (ARGs). However, the possible transmission of ARGs from the municipal solid waste treatment system (MSWT system) to ambient air is still unclear. In this study, we collected inside and ambient air samples (PM10 and PM2.5) and potential source samples (leachate and solid waste) in the MSWT system. The results showed that the MSWT system contributed to the increased ambient airborne bacteria and associated ARGs. Forty-one antibiotic-resistant bacteria (ARB) harboring blaTEM-1 were isolated, and the full-length nucleotide sequences of the blaTEM-1 gene (harbored by identical bacillus) from air (downwind samples) were 100% identical with those in the leachate and solid waste, indicating that the MSWT system was the important source of disperse bacteria and associated ARGs in the ambient air. The daily intake (DI) burden level of ARGs via PM inhalation was comparable with that via ingestion of drinking water but lower than the DI level via ingestion of raw vegetables. The antibiotic-resistant opportunistic pathogen Bacillus cereus was isolated from air, with a relatively high DI level of Bacillus via inhalation (104–106 copies/day) in the MSWT system. This study highlights the key pathway of airborne ARGs to human exposure.

    https://pubs.acs.org/doi/abs/10.1021/acs.est.9b07641