低剂量刺激效应在污染物风险评价中的意义及前景

Importance and Potential Application of Hormetic Effect in Risk Assessment of Environmental Pollutants

低剂量刺激效应(Hormesis效应)是一种有别于传统毒理学剂量-效应关系的特殊现象,是指机体受污染物低剂量胁迫时出现一定的刺激响应,而在高剂量作用条件下表现出抑制反应。研究表明,众多污染物在低浓度作用条件下都表现出对机体的Hormesis效应。污染物高剂量暴露的生态毒性研究成果已难以适用于环境中低浓度污染物的风险评价。本文拟综述介绍Hormesis效应的研究进展(主要包括Hormesis效应的研究历史、可能的作用机制);阐述Hormesis效应对污染物风险评价的影响,并对今后Hormesis效应的研究及应用方向进行展望。

Hormesis is a phenomenon characterized by a stimulation to the host triggered by a low dose of external stressors and an inhibition by a high dose,which is different from the classic concept of traditional dose-response relationship in toxicology.Studies suggest hormetic effect occurs in a variety of pollutants at low dosage.Thus,the findings of high-dose exposures inform previous eco-toxicity studies could not apply to the risk assessment of low-dose pollutants.This paper reviewed the advances in hormesis studies,with the focus on its historical foundation,generalization and possible mechanisms.Comments were provided on implications of hormesis in risk assessment.Key orientations of future research were also proposed.