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Endocrine Disruptors/PPCPsEndocrine Disruptor Chemicals
Endocrine disruptor chemicals (EDCs) interfere with the normal function of the endocrine system. However, which chemicals act as endocrine disruptors is a matter of debate. The 1996 Safe Drinking Water Act Amendments and the Food Quality Protection Act require the US Environmental Protection Agency to develop a screening and testing program to determine which chemical substances have possible endocrine disrupting effects in humans. To this end, the USEPA formed the Endocrine Disruptor Screening and Testing Advisory Committee in 1996 to design a screening and testing program to determine whether any unregulated contaminants behave as endocrine disrupting chemicals (EDCs). The final report was published in August 1998. The EDSTAC estimates that there are approximately 87,000 chemicals that should be considered for EDC screening. Of these, approximately 25,000 are polymers that have molecular weights greater than 1,000 g/mol, which would make crossing biological membranes and other barriers unlikely. Therefore these polymers would be unable to cause endocrine system effects. This leaves approximately 62,000 chemicals that need to be screened as possible EDCs.What drinking water contaminants are known endocrine disruptors? Naturally-occurring EDCs have been identified. Potential EDCs of concern include:
Current regulation of endocrine disruptors. USEPA, under the SDWA, currently regulates a number of suspected EDCs. Maximum contaminant levels (MCLs) have been established under the SDWA for the following suspected endocrine disruptors:
MCLs for these substances have been defined by toxic or cancer effects, not reproductive effects. However, if adverse effects to the endocrine system are determined to be at a lower level than the current MCL, the MCL can be changed to reflect the new information. Pharmaceuticals and Personal Care ProductsOften pharmacologically-active compounds (PhACs) and health care products are included in the EDC discussion. Another commonly used term is pharmaceutical and personal care products (PPCPs). PPCPs are not defined by specific health effects (i.e., endocrine disruption) but rather includes all products that are used as pharmaceuticals or personal care products. They typically find their way into source waters via sewage outflows, although veterinary antibiotics (and subsequent metabolites) can occur from farms using raw manure application. PPCPs include:
In addition to its long-standing efforts to assess occurrence of EDCs, USEPA recently initiated efforts to better understand the occurrence and potential health effects of PPCPs. Details are available at a new USEPA website on PPHPs as water pollutants. AWWA has also posted information for consumers on PPHP concerns at its DrinkTap.org site, issued a White Paper on Pharmaceuticals in Drinking Water, and published a consumer handbook on the issue titled "The Truth About Pharmaceuticals and Personal Care Products in Your Water" by former AWWA Executive Director Jack Hoffbuhr. It is available in the AWWA Bookstore along with several other relevant resources. Also, in 2008 Dr. Shane Snyder of the Southern Nevada Water Authority testified before Congress on behalf of AWWA in regard to assessing risks and taking actions to repond to pharmaceticals in water resources. Occurrence of EDCs and PPCPsWhile nearly everyone is exposed to EDCs or PPCPs either directly or indirectly, their occurrence in the environment is only recently becoming known as more monitoring has been conducted. A database of unregulated contaminant occurrence is maintained by the USEPA for use in analysis, rulemaking, and evaluation. Efforts to monitor for such compounds have increased in recent years, with most results revealing relatively widespread occurrence at very low levels. The US Geological Survey has also initiated a national reconnaissance to provide baseline information on the environmental occurrence of PPHPs and other "emerging contaminants" in US waters. See also:
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