药物与个人护理品（Pharmaceutical and personal care products, PPCPs）是一类化学物质的统称，属于新污染物。PPCPs目前已广泛应用于人类生产生活的多个领域，如人类和动物的疾病治疗，以及畜牧养殖和日用品使用等。PPCPs在水环境中广泛检出，对水生态系统和人类健康构成威胁。资江是长江的重要支流之一，流域内社会经济水平较低，畜牧业较为发达。因此，研究资江PPCPs的来源和时空变化机制，评价PPCPs的生态风险，对保护资江流域水生态系统和人群健康具有重要的理论和实际意义。
本研究调查了资江河水和沿岸主要污水厂进、出水中30种目标PPCPs（包括15种抗生素、6种雌激素以及9种家用与个人护理品），以期揭示资江河水PPCPs的时空变化规律及其机制，阐明资江PPCPs的来源，明确资江流域市政污水厂对PPCPs的去除效率及污水厂下游PPCPs的衰减规律，认知资江流域社会经济发展对资江PPCPs的影响，评价资江PPCPs的生态风险并筛选优先控制污染物。主要结果和结论如下：
资江河水中PPCPs广泛存在，除白霉素外29种目标PPCPs均在资江河水中检出。目标抗生素、雌激素和家用与个人护理品的平均检出率分别为70.9%、89.5%和82.1%，浓度范围分别为0.96~91.3 ng/L、2.67~97.5 ng/L和4.93~57.8 ng/L。抗生素中阿莫西林中位浓度最高（6.56 ng/L），雌激素中双酚A中位浓度最高（8.15 ng/L），家用与个人护理品中对羟基苯甲酸中位浓度最高（5.69 ng/L）。抗生素主要来源于市政污水、畜禽业污水、水产养殖及未处理生活污水；雌激素主要来源于人和畜禽排泄以及日常生活品释放；家用与个人护理品主要来源为市政污水厂排水和未处理生活污水直接排放。
资江河水中干季PPCPs浓度显著高于湿季，其主要原因为降水的稀释效应，同时受到源输入和PPCPs降解速率变化的影响。干季中抗生素、雌激素和家用与个人护理品的中位浓度分别是湿季的2.05、5.04和0.96倍。干季PPCPs浓度空间变化幅度高于湿季，主要因为干季降水稀释效应低、受污染源输入影响高。干季主要城市邵阳市、冷水江市和益阳市河段PPCPs浓度高，总体上PPCPs浓度从上游至邵阳市、冷水江市为上升趋势，而后至安化县为下降趋势，最后至下游益阳市为上升趋势。湿季PPCPs的浓度从中游新化县至下游益阳市总体为下降趋势，与降水稀释效应及雨季长江倒灌洞庭湖引起的河口稀释效应有关。
污水处理厂对抗生素、雌激素和家用与个人护理品的平均去除效率分别为56.6%、43.8%和55.2%。这表明污水厂无法将目标污染物完全去除，污水厂是资江河水中PPCPs污染的重要来源。PPCPs的去除效率与进水中PPCPs浓度显著相关，表现为随进水PPCPs浓度增加而快速升高和缓慢升高两个阶段。污水厂下游资江河水PPCPs浓度随迁移距离衰减，表现为5 km内快速衰减，5~17 km缓慢衰减。建立了以进水PPCPs浓度为自变量的污水PPCPs去除效率预测模型，以及以迁移距离为自变量的污水厂下游河流PPCPs浓度衰减预测模型。
社会经济和土地利用等对资江河水中PPCPs的浓度有重要影响。在县、市尺度上，农村人口、污水排放量、畜牧业产值、公共预算支出等社会经济因素与抗生素、雌激素以及PPCPs总浓度显著相关。建立的资江PPCPs土地利用回归模型表明，耕地和城市用地面积占比、地区生产总值、人口密度、农村人口、污水排放量、农林牧渔业总产值等因素显著影响河水中PPCPs浓度。
资江河水中PPCPs对水生态系统构成生态风险。抗生素对藻类构成高生态风险，雌激素对鱼类构成高生态风险，家用与个人护理品对藻类、甲壳类动物、无脊椎动物以及鱼类构成中、低生态风险。资江河水中抗生素导致抗性风险低。雌激素干扰潜力高，采样点的总雌激素活性均超过1 ng/L。优先控制污染物排序结果显示，应优先控制污染物为：己烯雌酚、17β-雌二醇、叔丁基羟基茴香醚、双酚A、三氯卡班。

Pharmaceuticals and personal care products (PPCPs) are a type of emerging pollutants, which were widely used in human and animal disease control, as well as health and cosmetics. They have been extensively detected in the aquatic environment, rising concerns about their impact on aquatic ecosystems. The Zijiang River is one of the important tributaries of the Yangtze River, with a low level of socio-economic development in the basin and a high proportion of livestock industry output. Therefore, it is crucial to investigate the sources and variations of PPCPs in the Zijiang River for protecting the aquatic ecosystem and public health in the basin.
Thirty target PPCPs were selected in this study, including 15 antibiotics, 6 estrogens, and 9 home and personal care products (HPCPs). This study investigated the occurrence of 30 target PPCPs in the water of the Zijiang River and the influent and effluent of major sewage treatment plants (STPs) along the river. The aim of this study was to explore the spatiotemporal variation and mechanism of PPCPs in the Zijiang River, clarify their sources, determine the removal efficiency of STPs on PPCPs, understand the impact of socio-economic development on PPCPs in the river, assess the ecological risk of PPCPs in the river, and identify priority pollutants for control. The main results and conclusions are as follows:
Target PPCPs were widely detected in the water of the Zijiang River, except for leucomycin. The average detection frequency of target antibiotics, estrogens, and HPCPs were 70.9%, 89.5%, and 82.l%, respectively. The concentration of antibiotics, estrogens, and HPCPs ranged from 0.96 to 91.3 ng/L, 2.67 to 97.5 ng/L, and 4.93 to 57.8 ng/L, respectively. The median concentration of amoxicillin was found to be the highest among all target antibiotics, measuring at 6.56 ng/L. In terms of estrogens and HPCPs, bisphenol A and p-hydroxybenzoic acid exhibited the highest median concentrations at the level of 8.15 ng/L and 5.69 ng/L, respectively. The main sources of antibiotics included STP effluent, sewage from livestock and aquaculture, and untreated domestic sewage. The main sources of estrogens were excretion from humans and animals, as well as the release from daily consumer products. The main sources of HPCPs included STP effluent and untreated domestic sewage.
The concentration of PPCPs in the Zijiang River was significantly higher in the dry season than the wet season, which were primarily due to precipitation dilution, variations in source discharge, and PPCP degradation rates. The median concentrations of antibiotics, estrogens, and HPCPs in the dry season were 2.05, 5.04, and 0.96 times higher than those in the wet season, respectively. In the dry season, elevated PPCPs concentration were observed in the urban river segments, including those in Shaoyang City, Lengshuijiang City, and Yiyang City. In general, PPCPs concentration in the dry season exhibited an increasing trend from the upstream to Shaoyang City and Lengshuijiang City, then a decreasing trend to Anhua County, and an increasing trend to Shaoyang City. While in the wet season, a decrease trend was found in PPCPs concentration from midstream to downstream, primarily due to dilution effects resulting from precipitation and backflow from Dongting Lake.
The average removal efficiencies of antibiotics, estrogens, and HPCPs in STPs were found to be 56.6%, 43.8% and 55.2%, respectively. The findings revealed that the major STPs along the Zijiang River were unable to completely remove the target PPCPs, highlighting the significant role of STP effluent in PPCPs pollution in the Zijiang River. A prediction model was developed to estimate the removal efficiency of PPCPs in STPs, with the PPCPs concentration in the influent as the independent variable. The removal efficiency exhibited a significant correlation with the PPCPs concentration in the influent, indicating two stages of rapid and gradual increase as the PPCPs concentration rises. The prediction model for the attenuation of PPCPs concentration downstream of STPs was established, incorporating migration distance as an independent variable. The concentration of PPCPs decreases downstream of STPs as migration distance increases, exhibiting a rapid attenuation within 5 km followed by a gradual decrease between 5-17 km.
The concentrations of PPCPs in the Zijiang River are significantly affected by the socioeconomic factors and land use in the basin. At the county or city level, there was a significant correlation between the concentrations of antibiotics, estrogens, and total PPCPs with socioeconomic factors, such as rural population, STP effluent, and public budget expenditure. A land use regression model for the prediction of PPCPs concentration in the Zijiang River was established. The model indicated that the proportion of arable land area, rural population, and gross output value of agriculture significant affected PPCPs concentration in the Zijiang River.
The PPCPs in the Zijiang River posed ecological risks to the aquatic ecosystem. Antibiotics posed a high-level ecological risk to algae, while estrogens posed a high-level risk to fish. HPCPs posed moderate to low level risk to aquatic organisms in the Zijiang River. The antibiotic resistance risk in the Zijiang River was at a low level. Estrogens exhibited a high endocrine disrupting effect, with total estrogenic activity at all sampling sites exceeding 1 ng/L. The prioritized control pollutants of targe PPCPs in the Zijiang River were determined to be diethylstilbestrol, 17β-estradiol, butylated hydroxyanisole, bisphenol A, and triclocarban.