Antibiotic pollution in aquatic systems is a concern for human and environmental health. The concern is largely due to the global occurrence of antibiotic-resistant bacteria. From 2017 to 2018 in the NC Piedmont, 15 ion masses associated with antibiotics were detected in rural streams and groundwater. Four of these masses were confirmed to be antibiotics through target analysis (sulfamethoxazole, sulfamerazine, erythromycin, danofloxacin). Concentrations of antibiotics were as high as 1.8 μg/L. As a follow-up, antibiotic residues in urban streams sites in Greensboro, NC, USA, were investigated. Urban streams are heavily influenced by the dense populations surrounding them. In the fall, winter, and spring seasons, surface water was collected from eight sites along two urban streams. Sampling was conducted at streams sites above and below municipal hospitals and wastewater treatment facilities in the study area. At the conclusion of the survey, nine ion masses associated with antibiotics used in both human and veterinary medicine were detected from surface water collected. Three of the four antibiotics targeted in rural stream samples were detected and confirmed in urban stream samples (sulfamerazine, danofloxacin, and erythromycin). Detection frequencies of the three antibiotics ranged from 0 to 46%. Concentrations of each target antibiotic was as followed: SMX (0 to <10 ng/L), SMR (0 to <11 ng/L), DAN (0 to <20 ng/L), and ETM (0 to <15 ng/L). Each target antibiotic concentration was below our methods quantification limits. Our risk assessment analysis showed that the target antibiotics posed no risk to fish, daphnia, and green algae within this region of NC (RQ < 0.1). Compared to rural streams in this region of NC, antibiotic pollution is less prevalent in urban streams. The differences between urban and rural streams may be driven by the varying land use and suggest more research should be dedicated to monitoring these contaminants in rural areas of the United States.

水生系统中的抗生素污染是对人类和环境健康的关注。这种担忧主要是由于全球出现抗生素耐药性细菌。从 2017 年到 2018 年，在北卡罗来纳州皮埃蒙特，在农村溪流和地下水中检测到 15 个与抗生素相关的离子团。其中四个肿块通过靶点分析被证实为抗生素（磺胺甲恶唑、磺胺美拉嗪、红霉素、达诺沙星）。抗生素浓度高达1.8 μg/L。作为后续研究，调查了美国北卡罗来纳州格林斯伯勒城市溪流中的抗生素残留。城市溪流深受其周围密集人口的影响。在秋季、冬季和春季，地表水是从两条城市溪流的八个地点收集的。在研究区域的市政医院和废水处理设施上方和下方的溪流地点进行采样。在调查结束时，从收集的地表水中检测到九个与用于人类和兽医的抗生素相关的离子质量。在城市河流样本中检测并确认了针对农村河流样本的四种抗生素中的三种（磺胺美拉嗪、达诺沙星和红霉素）。三种抗生素的检测频率范围为 0 至 46%。每种目标抗生素的浓度如下：SMX（0 至 <10 ng/L）、SMR（0 至 <11 ng/L）、DAN（0 至 <20 ng/L）和 ETM（0 至 <15 ng/L） /L)。每个目标抗生素浓度都低于我们的方法定量限。我们的风险评估分析表明，目标抗生素对鱼类没有风险，北卡罗来纳州该区域内的水蚤和绿藻（RQ < 0.1）。与北卡罗来纳州该地区的农村溪流相比，抗生素污染在城市溪流中不太普遍。城市和农村河流之间的差异可能是由不同的土地利用驱动的，并建议更多的研究应该致力于监测美国农村地区的这些污染物。