In a newly updated report, Traces of Environmental Chemicals in the Human Body: Are They a Risk to Health?, the physicians and scientists of the American Council on Science and Health (ACSH) conclude that the mere ability to measure small amounts of environmental chemicals in human blood and other tissue is not an indication of the presence of a health hazard. ACSH scientists came to a similar conclusion based on review of the scientific evidence in 1999, at the time of the publication of the first edition of this paper. Nothing has been published to conflict with that conclusion over the ensuing four years.
People are exposed constantly to all sorts of environmental chemicals. Some of these chemicals are man-made; others occur naturally. The human body absorbs many of them. According to Gilbert Ross, M.D., ACSH's Medical Director, "Chemicals are ubiquitous; indeed, we are all composed of chemicals. Different chemicals have widely variable health effects. Some, if absorbed in large enough amounts, can cause harm. Some, including therapeutic pharmaceuticals and certain minerals, are, in appropriate amounts, actually beneficial or even essential for life itself."
"The human body has numerous mechanisms built in to deal with environmental chemicals," says ACSH President Dr. Elizabeth Whelan. "The body can change some of them chemically to varying degrees. It may excrete a substance shortly after exposure or may store it for varying periods of time."
Scientists and physicians who study exposures to trace chemicals look for biomarkers measurable changes in cells or biological processes to reflect whether people have certain substances in their bodies. A finding that a particular biomarker is present in the body does not necessarily indicate an adverse health effect, however. Many biomarkers simply indicate that an exposure has occurred.
Dr. Whelan also points out: "Americans are constantly being bombarded with warnings about dire health consequences from traces of environmental chemicals. But, in truth, many of these warnings simply relate to evidence of exposure, not to any demonstrated adverse effects on health. Merely because a substance can be detected does not mean that it poses any real risk to health. Indeed, there are almost no studies documenting an adverse human health effect due to trace levels of chemicals."
Traces of Environmental Chemicals in the Human Body provides a straightforward explanation of the factors that must be considered in any attempt to incriminate exposures to environmental chemicals as a significant contributor to adverse health effects in humans. The report also offers valuable data on recent trends in Americans' exposures to various substances which have been publicized as causing health effects.
