Abstract:
Society demands products which contain chemicals or require chemicals for their production. Exposure to many of these chemicals as well as many natural agents may produce adverse health effects in humans if he dose is sufficiently large. Minimizing the potential dor adverse effects necessitates the reduction of exposures to these agents. For an agent to produce an adverse health effect, it must first be absorbed. The primary routes of entry of such compounds are inhalation, ingestion, and dermal absorption. Once absorption of the compound has occured, it is distributed into different compartments of the body. The agent may be eliminated unchanged in either urine or expired air, or interact with the organism by binding to its molecular target site within a tissue. This binding may either be reversible or non-reversible. Adverse effect on health requires biological interactions of the organism with the chemical compound or agent. Evaluation of possible health effects can be approached by focusing on one of three elements - health surveillance, environmental or occupational exposure assessment, and biomonitoring. Health surveillance looks at the health outcome of exposures. While centering on individuals, it requires that an effect has already occured. Therefore, it is more of a corrective or mitigative approach to health. Prevention of disease is possible through the focus on exposure to or internal dose of an agent. Environmental monitoring attempts to assess health risks by monitoring exposure to an agent in food, water, and air, whereas occupational monitoring focuses on exposure through inhalation and dermal absorption. Occupation monitoring has traditionally applied standards based upon ambient air concentrations in order to prevent adverse health effects, with little or no evaluation of internal dose. While ambient and personal air monitoring is important for assessing exposure to contaminants from emission sources, it offers no specific information on an individual's body burden or pharmacokinetic interaction with the compound, and therefore provides an imprecise means for assessing individual health risks.
Taken from the beginning of thesis.