Posthuma Leo, de Zwart Dick
National Institute for Public Health and the Environment, Laboratory for Ecological Risk Assessment, P.O. Box 1, NL-3720 BA Bilthoven, The Netherlands.
Environ Toxicol Chem. 2006 Apr;25(4):1094-105. doi: 10.1897/05-305r.1.
The purposes of this study were to investigate whether exposure to toxicant mixtures is associated with fish assemblage characteristics in the field and to describe the relationships between predicted chronic and acute mixture risks and observed impacts. Fish abundance and abiotic monitoring data from Ohio, USA, surface waters were compiled and analyzed. Variability of biotic and abiotic parameters was large. Exposure assessment, risk assessment with species-sensitivity distributions, and mixture toxicity rules were used to calculate a relative risk predictor: The multisubstance potentially affected fraction of species (msPAF). Predicted acute and chronic risks ranged from low values to more than 10 and 50% of species potentially affected, respectively. Pearson correlations between predicted risk and observed assemblage characteristics were nonsignificant for total abundance, number of species, Shannon-Weaver index, and evenness. Moderately significant correlations were found between predicted risk and abundance for 23% of individual species. Both abundance increases and decreases were observed. Generalized linear model (GLM) regressions revealed significant nonlinear associations between predicted risk and the abundance for 50% (metals and ammonia) and 55% (household product ingredients) of the species. Local ecological impact was expressed as the fraction of species expected but not observed, both with and without attribution of impact to mixture exposure. The association between predicted impacted fraction and the fraction of species expected but not observed was not significant. Predicted acute and chronic impacted fractions were associated significantly with the observed fraction of species likely lost by the action of toxicant mixtures under field conditions, with wide confidence bounds. These findings confirm the view that higher mixture impacts are expected in the field at higher msPAF.
本研究的目的是调查接触有毒物质混合物是否与野外鱼类群落特征相关，并描述预测的慢性和急性混合物风险与观察到的影响之间的关系。收集并分析了来自美国俄亥俄州地表水的鱼类丰度和非生物监测数据。生物和非生物参数的变异性很大。使用暴露评估、基于物种敏感性分布的风险评估和混合物毒性规则来计算相对风险预测指标：多物质潜在受影响物种分数（msPAF）。预测的急性和慢性风险范围从低值到分别超过10%和50%的潜在受影响物种。预测风险与观察到的群落特征（总丰度、物种数量、香农-韦弗指数和均匀度）之间的皮尔逊相关性不显著。在23%的单个物种中，预测风险与丰度之间发现了中度显著的相关性。观察到丰度既有增加也有减少。广义线性模型（GLM）回归显示，对于50%（金属和氨）和55%（家用产品成分）的物种，预测风险与丰度之间存在显著的非线性关联。局部生态影响表示为预期但未观察到的物种比例，无论是否将影响归因于混合物暴露。预测的受影响比例与预期但未观察到的物种比例之间的关联不显著。预测的急性和慢性受影响比例与在野外条件下可能因有毒物质混合物作用而损失的观察到的物种比例显著相关，置信区间较宽。这些发现证实了这样一种观点，即在野外，msPAF越高，混合物的影响越大。
