In analytical chemistry, biomonitoring is the measurement of the body burden of toxic chemical compounds, elements, or their metabolites, in biological substances. Often, these measurements are done in blood and urine.
The two best established biomonitoring programs in representative samples of the general population are those of the United States and Germany, although population-based programs exist in a few other countries. In 2001, the U.S. Centers for Disease Control and Prevention (CDC) began to publish its biennial National Report on Human Exposure to Environmental Chemicals, which reports a statistically representative sample of the U.S. population. The Environmental Working Group has also conducted biomonitoring studies.
Historically, public health regulations have been based on theoretical risk calculations according to known levels of chemical substances in air, water, soil, food, other consumer products and other sources of potential exposure. Human biomonitoring offers the opportunity to analyze the actual internal levels of bodily substances from all potential routes of exposure at one time, which may contribute to improving risk assessments. Scientific advancements have made it possible to detect a greater number of chemical substances in smaller concentrations in the body, with some chemicals detectable at levels as low as parts per trillion. A single biomonitoring measurement is only one snapshot in time and may not accurately reflect the level of exposure over longer periods.