Collection and handling of biomarkers of inorganic arsenic exposure in statistical analyses

Toxic chemicals, such as arsenic, lead, cadmium, various types of pesticides, and other persistent and nonpersistent pollutants, can be harmful to human health even at fairly low doses. Understanding the effects of chemicals on disease processes or endpoints requires the collection of information on exposure levels. Such exposure assessment often occurs by measuring the concentrations of chemicals in air, food, and drinking water, because these media are easy to collect and involve few ethical concerns. However, exposure assessment using biomarkers may be preferable because it can measure the internal dose (inside the human body) of the chemical or its metabolites and integrates information on an individual's exposure from all sources. The use of biomarkers for exposure assessment requires knowledge of the kinetics of chemicals inside the body and due consideration of ethical aspects of sample collection and data handling.