Abstract:

Antibiotics have attracted global attention because of their potential ecological and health risks. At present, the human health ambient water quality criteria (AWQC) study of antibiotics in the Yangtze River basin is lacked, limiting the further development of the control and risk assessment of antibiotic pollutants in China. In order to promote the research on human health AWQC and human health risk assessment of antibiotic pollutants in the Yangtze River basin, we analyzed the contaminated levels of ofloxacin (OFL) and chlortetracycline (CTC) in surface water and fish samples (different trophic levels) in the Yibin (upstream), Chongqing (upstream), Yichang (upstream), Wuhan (midstream), and Shanghai (downstream) of the Yangtze River basin, respectively (Sampling sites involve the Yangtze River's main stream, tributaries, coastal reservoirs and densely populated urban areas along the river). The AWQC of OFL and CTC in the Yangtze River basin were conducted by analyzing the final trophic level bioaccumulation factors (A_fi) of OFL and CTC in fish at the 2, 3 and 4 trophic levels, as well as combining the antibiotic toxicological parameters and population exposure parameters through drinking water and consumption of aquatic products. The results showed that the mass concentration of OFL and CTC in Yangtze River waters were ND-1.55×10⁻⁴ mg∙L⁻¹ and ND-4.17×10⁻⁴ mg∙L⁻¹, respectively. The mass fraction of OFL and CTC in fish were ND-4.94×10⁻² mg∙kg⁻¹ and ND-0.108 mg∙kg⁻¹. The fish A_fi of OFL at trophic levels 2, 3 and 4 were 1.40×10³ L∙kg⁻¹, 79.0 L∙kg⁻¹ and 172 L∙kg⁻¹; the fish A_fi of CTC at trophic levels 2, 3 and 4 were 755 L∙kg⁻¹, 9.19×10⁴ L∙kg⁻¹ and 744 L∙kg⁻¹. The AWQC of OFL and CTC were 3.04 μg∙L⁻¹ and 0.250 μg∙L⁻¹, respectively. The results showed that the human health risk of OFL in the Yangtze River basin was temporarily acceptable, but the CTC concentration in surface water in Yibin was higher than the conducted AWQC, indicating that the CTC concentration variation in the Yangtze River basin and the possible human health risk should be pay more attention. These observations may provide a reference for the scientific development of water environmental quality standards for antibiotics in Yangtze River basin and the assessment of the human health risks.

Key words: ofloxacin, chlortetracycline, human health, ambient water quality criteria, Yangtze River basin

摘要：

抗生素因其潜在的生态和健康风险而引起全球关注。目前，中国长江流域抗生素的人体健康水质基准研究尚处于空白阶段，不利于国家进一步开展抗生素新污染物的管控和风险评估工作。为促进长江流域抗生素污染物的人体健康水质基准研究和人体健康风险评估工作的开展，分别在长江流域宜宾段（上游）、重庆段（上游）、宜昌段（上游）、武汉段（中游）和上海段（下游）采集并分析了表层水样和不同营养级鱼样中氧氟沙星（OFL）和金霉素（CTC）的含量（采样点涉及长江干流、支流、沿江水库以及沿江城镇密集区）。通过分析长江流域OFL和CTC在第2、3、4营养级鱼类的最终营养级生物累积系数（A_fi），结合抗生素毒理参数和人群暴露参数，在饮水和消费水产品两种暴露途径下，推导出了长江流域OFL和CTC的人体健康水质基准（AWQC）。结果表明，长江流域水体中OFL和CTC的质量浓度分别为ND-1.55×10⁻⁴、ND-4.17×10⁻⁴ mg∙L⁻¹，鱼体中OFL和CTC的质量分数分别为ND-4.94×10⁻²、ND-0.108 mg∙kg⁻¹；OFL在第2、3、4营养级鱼类中的A_fi分别为1.40×10³、79.0、172 L∙kg⁻¹，CTC在第2、3、4营养级鱼类中的A_fi分别为755、9.19×10⁴、744 L∙kg⁻¹；OFL和CTC的AWQC分别为3.04、0.250 μg∙L⁻¹。该结果显示长江流域OFL的人体健康风险暂时处于可接受水平，但长江流域宜宾段局部水体CTC浓度高于推导出的水质基准则表明仍需重点关注长江流域CTC的浓度变化情况及其可能会带来的人体健康风险。研究结果可为科学制定长江流域抗生素的水环境质量标准和评估其人体健康风险提供参考依据。

关键词: 氧氟沙星, 金霉素, 人体健康, 水质基准, 长江流域