ABSTRACT
Risk assessment is the systematic evaluation of the factors that might result in an adverse human health effect resulting from exposures to contaminants and often the attempted quantification of those factors and effects. The expression of a human health risk is dependent upon two principal components—toxicity and exposure. The hazard identification step is generally the same for outdoor and indoor pollutants; it involves a determination of whether adverse health effects are associated with exposure to a specific substance. This determination can involve: gathering physical and chemical properties of the substance; conducting or evaluating toxicological studies on animals, humans, or other laboratory species; gathering metabolic and physiological data on animals and humans; and investigating likely pathways of exposure. The dose–response assessment step looks beyond the hazard identification and attempts to determine the specific responses that can occur at varying doses.
