浙南瓯江流域水体抗生素污染特征及风险评价

Characteristics and Risk Assessment of Antibiotic Contamination in Oujiang River Basin in Southern Zhejiang Province

环境中抗生素污染对生态系统安全产生负面影响.以瓯江流域为例,采用高效液相色谱-串联质谱法对浙南诸河流域水体中6类35种抗生素浓度进行检测,分析抗生素的浓度水平和空间分布,利用相关模型评估抗生素对生态和人体的健康风险,讨论抗生素的来源.结果表明,瓯江流域地表水20个采样点中4类12种抗生素均有不同程度检出,分别是磺胺类、喹诺酮类、四环素类和林可酰胺类,总浓度为ND~1 018 ng·L^(-1).其中检出率较高的是林可霉素,为90.48%,其次是磺胺吡啶,为38.10%.检出浓度平均值最大的3种抗生素分别是氧氟沙星(12.49 ng·L^(-1))、林可霉素(11.08 ng·L^(-1))和双氟沙星(7.38 ng·L^(-1)).流域内抗生素以点状污染为主,空间分异性较大,上游抗生素浓度平均值(54.39 ng·L^(-1))大于中下游浓度平均值(46.64 ng·L^(-1)),抗生素污染程度由上游至下游呈现出“上疏下密”的特点;上游污染主要来源为医疗和畜禽养殖业废水的排放,下游污染主要为人口活动密集和经济产业快速发展所导致.生态风险评估结果表明,上游采样点H6具有最大的风险商值,其中氧氟沙星和恩诺沙星具有高风险水平,林可霉素具有中风险水平.健康风险评估结果表明,瓯江流域水体抗生素对人体健康无风险.

Antibiotic pollution in the environment has a negative impact on ecosystem security.Taking the Oujiang River Basin as an example,high-performance liquid chromatography mass spectrometry(LC-MS)was used to detect the concentration of six classes of 35 antibiotics in the surface water of the southern Zhejiang River Basin.The concentration level and spatial distribution of antibiotics were analyzed,the risk of antibiotics to ecology and human health were assessed using relevant models,and the sources of antibiotics were discussed.The results showed that in 20 sampling sites,a total of four classes of 12 antibiotics were detected,including sulfonamides,quinolones,tetracyclines,and lincosamides.The total concentration was ND-1018 ng·L^(−1).The highest detection rate was that of Lincomycin(90.48%),followed by that of sulfapyridine(38.10%).The three antibiotics with the highest average concentrations were ofloxacin(12.49 ng·L^(−1)),Lincomycin(11.08 ng·L^(−1)),and difloxacin(7.38 ng·L^(−1)).Antibiotics in the basin showed mainly spotty pollution,which had large spatial differentiation.The average concentration of antibiotics in the upstream(54.39 ng·L^(−1))was higher than that mid-downstream(46.64 ng·L^(−1)).The degree of antibiotic pollution from upstream to downstream showed a characteristic of being"sparse in the upstream and dense in the downstream."This indicated that the concentration of antibiotics in the upstream was significantly different,whereas the pollution degree of antibiotics in the downstream was uniform.The upstream was mainly polluted by health,livestock,and poultry breeding wastewater emissions,and downstream pollution was mainly caused by densely populated activities and the rapid development of economy,trade,and industry.The ecological risk assessment results showed that the upstream site H6 had the highest risk quotient,ofloxacin and enrofloxacin had high risk levels,and lincomycin had a moderate risk level.Health risk assessment results showed that the Oujiang River surface water antibiotics posed no risk to human health.