<b>Priority control of classical contaminants over emerging contaminants in the Asia’s largest river sediments</b>

Chemical pollution of aquatic environments is growing global concern, however, it is still unclear what compounds deserve more attention. Here we proposed to use the environmental health prioritization index method in conjunction with the principle of risk maximization to determine the priority list of 112 typical micro-organic contaminants (including classical and emerging contaminants) in the Asia’s largest river – Yangtze River. The results showed that naphthalene, bis(2-ethylhexyl) phthalate, pyrene, di-isobutyl phthalate, phenanthrene, di-n-butyl phthalate and benzo<b>fluoranthene were the top 7 pollutants in the whole basin. When compared with emerging contaminants, it was interestingly found that the two classical contaminants (e.g., polycyclic aromatic hydrocarbons and phthalate esters) were the most dominant in the priority list, either from the whole basin or provincial level. This study offered a feasible methodology for priority substances screening, in addition, the meaningful findings would be beneficial to the effective management and control of chemical contaminants.</b>水生环境的化学污染日益成为全球关注的焦点，但目前仍不清楚哪些化合物需要得到更多重视。本研究提出结合环境健康优先指数法（environmental health prioritization index method）与风险最大化原则，对亚洲第一大河长江流域内的112种典型微量有机污染物（micro-organic contaminants，涵盖经典污染物与新兴污染物）开展优先级排序工作。研究结果显示，萘（naphthalene）、邻苯二甲酸二(2-乙基己基)酯（bis(2-ethylhexyl) phthalate）、芘（pyrene）、邻苯二甲酸二异丁酯（di-isobutyl phthalate）、菲（phenanthrene）、邻苯二甲酸二正丁酯（di-n-butyl phthalate）以及苯并[b]荧蒽（benzo[b]fluoranthene）为全流域排名前7的污染物。与新兴污染物对比后可发现，无论是全流域尺度还是省级尺度，两类经典污染物——多环芳烃（polycyclic aromatic hydrocarbons）与邻苯二甲酸酯类（phthalate esters）均在优先级列表中占据主导地位。本研究为优先筛查污染物提供了一套可行的方法体系，其具有实际意义的研究结果也将有助于化学污染物的有效管控。