Challenges Surround Biomonitoring Studies

As the number of human biomonitoring studies begins to escalate, many challenges surround their effective use, according to a new report from the National Research Council. Biomonitoring means measuring a chemical or its metabolite in humans, usually in blood or urine, for assessing exposures to natural and synthetic chemicals.

Interpreting what biomonitoring data mean in terms of public health is often difficult, the report says. The ability to detect a chemical in humans often exceeds the ability to determine whether that chemical causes a health risk or to evaluate the source of exposure to the chemical.

And the design of biomonitoring studies is often problematic, the report says, as there is no coordinated, public-health-based strategy for selecting the chemicals to be measured. "There is a need for a consistent rationale for selecting chemicals for study based on exposure and public health concerns," the NRC panel wrote.

Many population-based studies on chemical exposure are conducted in the U.S. by the Centers for Disease Control & Prevention, the Environmental Protection Agency, and the National Institutes of Health. CDC has published periodic reports on human exposure to environmental chemicals.

The NRC report recommends several areas of research that could improve biomonitoring. It wants a coordinated strategy developed for selecting chemicals based on their potential to cause harm and on widespread population exposure. It also wants studies conducted that could help interpret the risk from chemicals in the environment. Where possible, researchers should "enhance exposure assessment, epidemiologic, and toxicologic studies with biomonitoring to improve the interpretation of results," the report says.

In addition, research on public communication is needed to understand how to communicate the results of biomonitoring studies effectively. For example, participants in biomonitoring studies almost never learn what their own exposure levels were for the chemicals measured. However, sharing results raises ethical issues, the report says. In some cases, it might be important to provide clinical follow-up to those participants with exceptionally high levels of harmful chemicals.

The American Chemistry Council praises the report. "We believe the [NRC] report provides a very useful benchmark for future as well as current research efforts," says Richard A. Becker, ACC's senior toxicologist. "In particular, it emphasizes the need to use rigorous scientific methods for sampling, evaluating, and reporting the data."

The report can be found online at newton.nap.edu/catalog/11700.html.