Sidebar: Risk assessment defined
Risk assessment is the characterization of the potential adverse health effects of human exposures to substances such as pesticide residues. It also includes characterization of uncertainties inherent in the process.
Risk assessments consist of the following steps:
Hazard identification, which is the determination of whether a particular chemical is or is not causally linked to particular health effects.
Dose-response assessment, which is the determination of the relation between the magnitude of exposure and the probability of occurrence of the health effects in question.
Exposure assessment, which is the determination of the extent of human exposure before or after application of regulatory controls.
Risk characterization, which is the description of the nature and often the magnitude of human risk, including attendant uncertainty.
In each step, a number of decision points occur where risk to human health can only be inferred from the available evidence and judgments must be made regarding the analytic approach to be taken.
Conservative guideline: The term conservative has been used to describe inference options in hazard identification that increase the likelihood that a substance will be judged to be a significant hazard to human health.
Dose-response relationship: This is the relationship between the dose of a chemical substance received and the resulting physiological response. The larger the dose, the greater the effect. (Also, see Threshold.)
Risk management: Risk management is the process of evaluating alternative regulatory options and selecting among them. A risk assessment may be one of the bases of risk management.
Threshold: The minimum dose of a substance that produces a physiological effect. At extremely low doses, most chemical substances are detoxified by the body. Carcinogens are thought to be the exceptions. Because most cancer-causing substances are genotoxic — causing direct damage to genes — any one damaged cell could eventually give rise to a tumor, and any dose is hypothetically capable of causing cancer.