BIOMONITORING

n order to determine what chemicals and how much of them are in your bodily tissues and fluids, the scientific technique of biomonitoring is used. Your exposure to both natural and synthetic substances, and how this exposure might be changing over time can be assessed with this technique.1 Minute amounts of chemicals are now detectable and measurable in the human body.

Biomonitoring results are used in a number of ways; one that is relevant to occupational exposures is to provide physicians with information about chemical exposures, and possibly shed some light on treatment interventions. Biomonitoring results can be used to advance our understanding of the health effects of environmental contaminants. This can lead to more protective public health policy.2

Samples for biomonitoring come from blood, serum, fatty tissue, breast milk, exhaled breath, urine, saliva, hair, and toenails. And if THAT doesn't sound invasive, I don't know what would be! Yet the controversy stems not from the invasive nature of the data collection but rather from how it is used and interpreted. Biomonitoring data are being generated so rapidly that it has outpaced the capacity of the scientific community to develop evaluation techniques to determine the sources of the chemicals and “whether or not a chemical measured in an individual, or a population, may cause a health risk.” In other words: “Our technical ability to generate new biomonitoring data has essentially exceeded our ability to interpret them. ”3 Also, some of the interpretative approaches involve modeling and extrapolation, which contribute to uncertainties and limitations in assessing the biomonitoring results.

The most important questions for biomonitoring efforts to address are questions that can't be definitively answered yet: does a measurable exposure to a chemical cause health effects, and, if so, what are the health risks presented by the measured chemicals? Biomonitoring can't answer these questions because toxicological data for too many chemicals is missing or insufficient. Further, risk assessment involves interpretation and extrapolation, which always brings controversy to the results. “The Government Accountability Office (GAO 2005) reports that EPA has [only] limited data on the health and environmental risks posed by chemicals now used in commerce.”4 This suggests that perhaps we need more government and private funding for studying the health effects of the chemicals that we are all exposed to on a daily basis. Especially for chemicals that present occupational exposure possibilities, exposures which tend to be higher dose and longer term—the perfect recipe for chemically-induced disease.

1. www.biomonitoringinfo.org
2. www.breastcancerfund.org
3. Human Biomonitoring for Environmental Chemicals (2006) Board on Environmental Studies and Toxicology (BEST)
4. ibid