摘要

       垃圾填埋场每年在全球范围内接收约3.5亿吨城市固体废物，包括抗生素和其他影响抗生素耐药性的共选剂。然而，对于填埋场的AMR，特别是作为填埋年龄的函数，人们知之甚少。在这里，我们量化了不同年龄垃圾填埋场垃圾和沥滤液中的抗生素、重金属和AMR基因（ARGs）。旧垃圾填埋场的垃圾和沥滤液中的抗生素水平始终较低，而沥滤液中的精氨酸水平随着填埋场年龄的增加而显著增加（单向方差分析，F=10.8，P<0.01）。随着填埋场年龄的增加，重金属含量增加（单因素方差分析，F=12.3，P<0.01）与浸出液中ARGs水平升高（Mantel检验，R=0.66，P<0.01）显著相关，这意味着旧填埋场周围的AMR暴露风险更大。为了进一步解释ARGs的年龄分布机制，对垃圾和渗滤液样品中的微生物群落、移动遗传元素（MGEs）和环境因子进行了对比。垃圾中的微生物群落与ARG含量密切相关（Procrustes检验；M2=0.37，R=0.86，P<0.001），而浸出液中的ARG与MGEs的相关性更大。

        Landfills receive about 350 million tons of municipal solid wastes (MSWs) per year globally, including antibiotics and other coselecting agents that impact antimicrobial resistance (AMR). However, little is known about AMR in landfills, especially as a function of landfill ages. Here we quantified antibiotics, heavy metals, and AMR genes (ARGs) in refuse and leachates from landfills of different age (<3, 10, and >20 years). Antibiotics levels were consistently lower in refuse and leachates from older landfills, whereas ARG levels in leachates significantly increased with landfill age (One-way ANOVA, F = 10.8, P < 0.01). Heavy metals whose contents increased as landfills age (one-way ANOVA, F = 12.3, P < 0.01) were significantly correlated with elevated levels of ARGs (Mantel test, R = 0.66, P < 0.01) in leachates, which implies greater AMR exposure risks around older landfills. To further explain ARGs distributional mechanisms with age, microbial communities, mobile genetic elements (MGEs) and environmental factors were contrasted between refuse and leachate samples. Microbial communities in the refuse were closely correlated with ARG contents (Procrustes test; M² = 0.37, R = 0.86, P < 0.001), whereas ARG in leachates were more associated with MGEs.

       https://pubs.acs.org/doi/10.1021/acs.est.7b03797