Chemical risk assessment

: Determination of the effect an agent has on health requires that the dose of the agent to a person be defined as accurately as possible. The correct estimation of exposure for occupational studies has received increasing attention in recent years and, as a result, a body of methodological literature has begun to take form. The importance of 'analysis and control of errors in exposure assessment, and integration with decision-making processes, is emphasized. This paper reviews the issues in the methodology of exposure assessment, particularly methods for quantitative retrospective assessment studies. The advantages of the use of validated statistical models are discussed.