基于SSD方法比较中美物种对铜的敏感性差异

基于无机铜(以下简称铜)对中、美淡水水生动物的毒性数据,构建了中、美水生动物对铜的SSD(物种敏感度分布)曲线,比较了中、美物种的HC₅(hazardous concentration at 5th percentile of the species,保护95%以上物种的浓度水平)及其差异. 结果表明:在HC₅下,中国的水生动物对铜的敏感性排序为节肢动物>非节肢动物>鱼类,无脊椎动物>脊椎动物；而美国不同物种对铜的敏感性排序为非节肢动物>节肢动物>鱼类,无脊椎动物>脊椎动物. 根据铜短期暴露的HC₅对中、美物种敏感性进行比较可知,中国鱼类、节肢动物和脊椎动物的敏感性均大于美国相应物种；而中国非节肢无脊椎动物和无脊椎动物均小于美国相应物种. 研究所选的美国全部物种对铜的敏感性略高于中国物种,但二者仅相差0.52 μg/L. 除非节肢无脊椎动物外,中、美水生生物对铜的SSD敏感性分布均未见显著差异. 因此,在推导中国水质基准时应注重考虑敏感性物种(如节肢动物). 

Comparison of Freshwater Biota Species Sensitivity Distributions to Copper in China and the United States

Based on acute toxicity data for freshwater species from China and the United States, species sensitivity distributions (SSDs) were developed to derive water quality criteria. Sensitivity to copper in taxa of vertebrates, invertebrates, fishes, arthropods, non-arthropod invertebrates and in all taxa were compared separately between species of China and the United States. The results suggest that under the 95% protection level, the sensitivity of various aquatic organisms in China to copper was in the order:arthropod > invertebrates > non-arthropod > fishes > vertebrates. With the same protection level, aquatic organisms in the United States were in the order:invertebrates > non-arthropod > arthropod > vertebrates > fishes. Based on the hazardous concentration at the 5^th percentile of the species (HC₅) value for short-term exposure to copper, vertebrates, fish and arthropods are more sensitive in China than in the United States with the exception of non-arthropods and invertebrates. No significant differences were observed between sensitivity distributions derived for species in China and the United States except for non-arthropods. Therefore, in determining the water quality criteria based on the sensitivities of all species, we should also consider the influence of SSD of individual groups.