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| Biomonitoring |
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| Background |
One of the key developments in human and environmental risk assessment over the past several decades has been a dramatic improvement in analytical chemistry. Today, scientists are able to accurately measure the presence of selected chemicals in nearly any kind of environmental sample down to parts-per-trillion levels, or lower. (Footnote 1) This capability has been increasingly used to measure the presence of manmade chemicals in humans - especially in blood, urine, organ tissues, and breast milk. Such "biomonitoring" studies have been conducted by government (e.g., Centers for Disease Control and Prevention (CDC), 2003), academic researchers, and several environmental groups (EWG, 2003; WWF-UK, 2004). Most have focused on agreed high priority toxic chemicals such as pesticides, dioxins, PCBs, and chlorinated organics.
Results from biomonitoring studies have clearly demonstrated that both naturally occurring and manmade chemicals can be found in human blood and urine at measurable quantities. However, the significance of these findings for human health has not been established, and especially government authorities have urged caution not to over-interpret results:
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"The measurement of an environmental chemical in a person's blood or urine does not by itself mean that the chemical causes disease. Advances in analytical methods allow us to measure low levels of environmental chemicals in people, but separate studies of varying exposure levels and health effects are needed to determine which blood or urine levels result in disease. These studies must also consider other factors such as duration of exposure. The Report does not present new data on health risks from different exposures" (CDC, 2003)
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Nonetheless, the detection of synthetic chemicals in humans has created considerable interest and debate. Some parties, especially environmental and public health organizations, have used biomonitoring data to support calls for bans on specific chemicals (EWG, 2003), or as support for major changes to existing chemicals legislation, such as the REACH proposal in Europe (WWF-UK, 2004). The studies have also generated public concern about whether "presence = problem."
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| Our view |
Procter & Gamble welcomes new advances in toxicology, analytical chemistry, modeling and risk assessment. Ensuring product safety is an essential priority for our business, and having better knowledge of the potential effects of chemicals, and exposures to humans and the environment, helps us continue to fulfill this commitment.
Carefully designed and implemented biomonitoring studies can be very useful in understanding the extent to which people may be exposed to both natural and manmade substances, as well as how they are metabolized in the body. The scientific literature contains hundreds of references to such research. A useful overview of biomonitoring background, research and recent publications can be found at a web-site sponsored by the Environmental Health Research Foundation.
P&G agrees with the caution expressed by the CDC to avoid over-interpretation of biomonitoring data. The presence of a particular chemical in human tissue is not an accurate measure of whether or not it will cause harm (risk). People are exposed to thousands of naturally occurring and manmade substances in the foods we eat, water we drink, and air we breath. As a consequence, many chemicals may be measurable in our bodies, yet have no adverse consequences.
In order to evaluate the risk of any chemical (natural or manmade), scientists must evaluate toxicity to humans, the thresholds where toxic effects can occur, and the extent of exposure (source, duration, and magnitude). These data are critical for understanding whether or not the presence of a chemical or its metabolites in the body is significant.
Attention should be focused on those chemicals that are most likely to harm human health, rather than substances that may be analytically detectable, but harmless. Otherwise, society could be deprived of numerous products and chemicals that improve both our health and well-being.
P&G recognizes that there are materials whose chemical properties require especially in-depth study and research, particularly if they are widely detected in humans or the environment. This includes chemicals that are broadly recognized as priority substances by the international scientific community and government authorities based on their persistence, potential to bioaccumulate, and toxicity (including those that are known in humans as carcinogens or mutagens). We avoid using such substances as ingredients in our products, unless we are confident that we can conduct a sufficiently thorough risk assessment to ensure that their use is safe. There may also be instances where such substances are found because they are residual contaminants of a raw material or components of a naturally occurring extract. These situations are also considered during our risk assessments.
P&G supports continued biomonitoring research, especially work to put such data into a risk context. We're especially supportive of a multistakeholder program by the Health and Environmental Sciences Institute biomonitoring sub-committee to develop guidance on how to integrate biomonitoring data into risk assessment (HESI, 2004). P&G is a member of this sub-committee, and we look forward to continued research and dialogue on this important emerging area.
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| References and Further Readings |
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| Footnote 1: For perspective, one part-per-trillion is the approximate equivalent of 1 drop of blood in a city of approximate 18 million people.back |
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