english.prescrire.org > Spotlight > Archives : 2010 > Assessing environmental health risks: managing uncertainty

Spotlight: Archives

Every month, the subjects in Prescrire’s Spotlight.

2010 : 1 | 30 | 60 | 90

Assessing environmental health risks: managing uncertainty

Risk assessment is necessary in order to anticipate and reduce the health impact of exposure to various agents present in the environment. Managing the complexity and uncertainties requires transparency and consistency.

Environmental risk management takes account of economic, political, technical, social and other factors. There are four stages to assessing health risks.

Stage 1: identifying hazards, by listing the agents to which populations are potentially exposed and identifying their harmful effects.

Stage 2: the relationship between exposure to an agent and its harmful effects is then given a "Human Toxicity Value” (HTV): the correlation between a dose of the agent and an effect or likely effect.

Stage 3: the exposure assessment, which is often surrounded by a degree of uncertainty, particularly for past exposures. Often the assessment is limited to possible exposure scenarios.

Stage 4: the synthesis of the first 3 stages. It involves estimating the risk and analysing the uncertainty surrounding the risk assessment.

Risk assessment presents uncertainties and limitations but it is still useful and necessary. Methods must be rigorous, transparent and independent.

©Prescrire February 2010

Source: "Évaluation des risques en santé environnementale" Rev Prescrire 2009; 29 (310): 612-617.