摘要
      新出现的令人担忧的污染物（CECs）在各大洲的水生环境中普遍存在，在发达国家也相对知名。然而，很少有研究调查它们在中低收入国家的存在及其生物影响。我们对加纳沃尔特河中CEC的存在进行了调查，并研究了这条具有经济和生态重要性的非洲河流沿线人类活动的微生物后果。在横跨118个地点的14个地点，用船或从岸上采集了水和沉积物样本 从沃尔特河口到阿科松博大坝的公里河道。制备样品提取物用于抗菌CECs、N，N-二乙基-甲基-甲苯酰胺以及全氟烷基和多氟烷基物质（PFAS；仅限水）的靶向分析。同时提取样品以表征微生物群落和抗生素抗性基因（ARGs）。抗生素和PFAS（PFAS，2-20 ng／L）在所有的水样中发现；然而，它们的浓度通常在每升低纳克的范围内，低于其他非洲、欧洲和北美研究报告的浓度。N、 所有样品中均存在N-二乙基-甲基-甲苯酰胺。在两种水中检测到的不同基因的数量（在1到10之间）和总ARG浓度各不相同（9.1 × 10−6至8.2 × 10−3）和沉积物（2.2 × 10−4至5.3 × 10−2），与城市发展、采砂、农业和贝类加工有关的地点的基因多样性增加。沉积物样品中ARG总浓度峰值与农业有关。没有注意到水质参数、CEC存在和/或ARGs之间的相关性。CEC在沃尔特河下游的存在凸显了其全球影响力。检测到的CEC的总体低浓度令人鼓舞，再加上缓解措施，可能会阻碍沃尔特河未来的CEC污染。《环境毒理学化学2022》；41:369–381。©2021 SETAC
Abstract
Contaminants of emerging concern (CECs) are ubiquitous in aquatic environments across all continents and are relatively well known in the developed world. However, few studies have investigated their presence and biological effects in low- and middle-income countries. We provide a survey of CEC presence in the Volta River, Ghana, and examine the microbial consequences of anthropogenic activities along this economically and ecologically important African river. Water and sediment samples were taken by boat or from shore at 14 sites spanning 118 km of river course from the Volta estuary to the Akosombo dam. Sample extracts were prepared for targeted analysis of antimicrobial CECs, N,N-diethyl-meta-toluamide, and per- and polyfluoroalkyl substances (PFAS; water only). Concurrent samples were extracted to characterize the microbial community and antibiotic-resistant genes (ARGs). Antibiotics and PFAS (PFAS, 2–20 ng/L) were found in all water samples; however, their concentrations were usually in the low nanograms per liter range and lower than reported for other African, European, and North American studies. N,N-Diethyl-meta-toluamide was present in all samples. The number of different genes detected (between one and 10) and total ARG concentrations varied in both water (9.1 × 10−6 to 8.2 × 10−3) and sediment (2.2 × 10−4 to 5.3 × 10−2), with increases in gene variety at sites linked to urban development, sand mining, agriculture, and shellfish processing. Total ARG concentration spikes in sediment samples were associated with agriculture. No correlations between water quality parameters, CEC presence, and/or ARGs were noted. The presence of CECs in the lower Volta River highlights their global reach. The overall low concentrations of CECs detected is encouraging and, coupled with mitigation measures, can stymie future CEC pollution in the Volta River. Environ Toxicol Chem 2022;41:369–381. © 2021 SETAC

https://setac.onlinelibrary.wiley.com/doi/abs/10.1002/etc.5279