基于风险商法的中国典型淡水水域微塑料生态风险评价

Ecological Risk Assessment of Microplastics in Typical Freshwater Waters in China Based on Method of Risk Quotient

微塑料是一种广泛存在于各种环境介质中的新兴污染物,但目前对于该污染物的生态风险评价方法尚不成熟。本文基于物种敏感性分布(species sensitivity distribution,SSD)使用风险商法,对中国13条典型河流微塑料污染进行了生态风险评估。首先构建了淡水生物对微塑料的敏感性分布曲线,计算出微塑料对淡水生物的预测无影响浓度为1.9×10^(5)n·m^(-3),再根据各河流的微塑料赋存状况计算出对应的风险商值。结果显示,洞庭湖、洪湖和三峡水库等6个水域的风险商值<0.1,无微塑料污染生态风险;珠江、太湖、鄱阳湖、茅洲河、岷江(成都段)和玛纳斯河有个别采样点风险商值>0.1,存在潜在微塑料污染生态风险;而黄河下游风险商值>1,存在较为严重的微塑料污染生态风险。

Microplastics are a kind of emerging pollutants widely present in various environmental media,but the ecological risk assessment methods for these pollutants are still immature.In this paper,an ecological risk assessment of microplastic pollution in 13 typical rivers in China was conducted based on species sensitivity distribution(SSD)using risk quotient method.Firstly,the sensitivity distribution curve of freshwater organisms to microplastics were constructed,and the predicted no-effect concentration of microplastics on freshwater organisms was calculated as 1.9×10^(5)n·m^(-3).Then the corresponding risk quotient values were calculated based on the occurrence of microplastics in each river.The results showed that the risk quotient of six rivers including Dongting Lake,Honghu Lake and Three Gorges Reservoir were less than 0.1,and there was no ecological risk of microplastics pollution.The risk quotient values of Pearl River,Taihu Lake,Poyang Lake,Maozhou River,Minjiang River(Chengdu Section)and Manas River were greater than 0.1,indicating potential ecological risks of microplastic pollution.However,the risk quotient value of the lower reaches of Yellow River was greater than 1,and there was a more serious ecological risk of microplastics pollution.