Leonards Pim E G, van Hattum Bert, Leslie Heather
Institute for Environmental Studies, VU University Amsterdam, De Boelelaan 1087, 1081 HVAmsterdam, The Netherlands.
Integr Environ Assess Manag. 2008 Oct;4(4):386-98. doi: 10.1897/IEAM_2008-008.1.
Accurate risk assessment of secondary poisoning by persistent organic pollutants (POPs) in top predators is possible but requires multidisciplinary input from wildlife ecology, ecotoxicology, and analytical chemistry. Because of the transfer of POPs up the food chain, traditional approaches to exposure assessment based on POPs in abiotic compartments or organisms low in the food chain can make the assessment of risk to top predators complicated. For more direct, accurate, and site-specific methods of assessing the risks of secondary poisoning of top predator by POPs, we classify 2 main approaches: diet based and tissue based. Exposure assessment via the diet-based approach requires samples of the predator's diet and measured concentrations in the prey items, realistic estimates of dietary composition, and ingestion rates. The even more direct, tissue-based approach uses measured POP concentrations in tissues of top predators to determine internal exposure coupled with tissue-based effect concentrations (or biological responses measured via biomarkers) to determine risk. The advantage of these methods is that uncertain estimates of POPs transfer to top predators from lower trophic levels are avoided. In practice, the availability of dose-response data and internal exposure-response relationships for POPs in top predators is limited, so these may have to be extrapolated from surrogate species. In this paper we illustrate and evaluate the potential of diet-based and tissue-based risk assessment approaches with case studies and demonstrate that appropriate methodologies significantly reduce the uncertainty in risk assessments of POPs.
准确评估顶级捕食者中持久性有机污染物（POPs）导致的二次中毒风险是可行的，但需要野生动物生态学、生态毒理学和分析化学等多学科的投入。由于POPs在食物链中的传递，基于非生物环境或食物链底层生物体内POPs的传统暴露评估方法会使顶级捕食者的风险评估变得复杂。为了采用更直接、准确且针对特定地点的方法来评估POPs对顶级捕食者造成二次中毒的风险，我们将主要方法分为两类：基于饮食的方法和基于组织的方法。通过基于饮食的方法进行暴露评估需要捕食者的食物样本、猎物中POPs的测量浓度、饮食组成的实际估计值以及摄食率。更为直接的基于组织的方法则利用顶级捕食者组织中测量的POPs浓度来确定体内暴露情况，并结合基于组织的效应浓度（或通过生物标志物测量的生物学反应）来确定风险。这些方法的优点是避免了对从较低营养级向顶级捕食者转移的POPs进行不确定的估计。在实际操作中，顶级捕食者中POPs的剂量反应数据和体内暴露 - 反应关系的可用性有限，因此可能需要从替代物种进行推断。在本文中，我们通过案例研究来说明和评估基于饮食和基于组织的风险评估方法的潜力，并证明适当的方法能显著降低POPs风险评估中的不确定性。
