(NADD)
What are PPCPs and EDCs? PPCPs include over-the-counter (OTC) medications, prescription medications, dietary supplements, hormones, cleaning agents (especially antibacterial cleaners), and the inert ingredients that are associated with these products (which can be just as harmful, if not more so, than the active ingredients themselves). Many of the PPCPs are actually designed to impact the human hormone system. Some PPCPs are also Endocrine Disrupting Chemicals (EDCs). The endocrine system is a complex network of hormones and glands which release hormones into the body and regulate growth, development and maturation. Endocrine disruptors are synthetic chemicals which either block or mimic natural hormones, which in turn disrupt normal functioning of organs.
How do PPCPs get into our drinking water? Many of the components of OTC drugs, supplements, and prescription medications are not completely metabolized by the human body. Therefore, the unmetabolized portions of these compounds are excreted when people defecate or urinate. For example, when amoxicillin, a common antibiotic, is ingested, 60% of the drug comes out unchanged in the urine (See “Survey of the New York City Watershed for the Presence of Pharmaceuticals,” NYS Department of Health, Troy, NY and Wadsworth Center for Laboratories and Research, NYS Department of Health, Albany, NY; (http://www.neiwpcc.org/ppcpconference/ppcp-docs/Barbara%20Hartley%20Grimes/BarbaraHartleyGrimes.pdf). Similarly, 40% to 50% of atenolol is excreted unchanged; and 90% of cephalexin (also known as the antibiotic Keflex).
Even if these compounds are then treated to the highest standards prescribed by state and federal law, the compounds make it into the waste stream and are discharged into the environment. Waste water treatment plants, such as the one proposed by Brickstone, are not designed or intended to remove these compounds from the waste stream.
What are the effects of PPCPs in our wastewater? From 1999 to 2002, the United States Geological Survey (USGS) studied surface and groundwater samples from around the country to determine whether PPCPs were present. They found at least one compound in 80% of streams and 93% of groundwater. The most commonly found compounds were: steroids, OTC medications (like ibuprofen), and insect repellants.
Different PPCPs have different toxilogical effects. For example:
The PPCPs triclosan and tricloscarban have been found to disrupt development in frogs (Veldhoen, N. et al, Aquatic Toxicology 80, The bactericidal agent triclosan modulates thyroid hormone-associated gene expression and disrupts postembryonic anuran development, (2006) 217-227); causes endocrine disruption in mussels (Canesi, L. et al., Effects of Triclosan on Mytilus galloprovincialis hemocyte function and digestive gland enzyme activities: Possible modes of action on non target organisms, Comparative Biochemistry and Physiology Part C 145, (2007) 464- 472); disrupts thyroid hormones in rats after only short-term exposure (Crofton, et al., Short term in Vivo exposure to the water contaminant triclosan: Evidence for disruption of thyroxine, (2007), (www.ealing.gov.uk). Triclosan and triclocarban are toxic to aquatic biota, bioaccumulate in algae and earthworms, are endocrine disruptors, can contain dioxin and other carcinogens, degrade to form other carcinogens, and are persistent in the environment (http://www.neiwpcc.org/ppcpconference/ppcp-docs/RolfHalden.pdf).
Antibiotics such as sulfamethoxazole, trimethoprim, erythromycin, and Keflex can get into the water and create antibiotic resistance. Antibiotics are turning up in surface and ground waters, and are of concern due to the fact that antibiotics in the environment selects for drug-resistant strains of bacteria. When bacteria are exposed to low doses of antibiotics, they develop a tolerance for those same drugs. When humans are subsequently infected with these drug-resistant bacteria, certain antibiotics are ineffective at treatment (see, e.g., http://www.ijc.org/rel/pdf/09_Pharma-fall2002.pdf). According to information released by the CDC in the fall of 2007, approximately 90,000 people die annually from antibiotic resistant infections. (http://www.fda.gov/FDAC/features/2002/402_bugs.html).
In 2006, the USGS found intersex fish in the Potomac River that were likely created by EDCs. EDCs are also responsible for other abnormal sexual function in non-human animals, such as decreased fertility. During a March, 2007 congressional briefing on compounds of emerging concern, Dana Kolpin, Chief of the U.S. Geological Survey's toxic substances hydrology program, stated that the USGS has "definitive" evidence from laboratory experiments that chemical compounds found in household detergents, drugs, and other compounds that pass through wastewater treatment plants are responsible for "feminizing" male fish downstream of such plants (http://www.mgsglaw.com/ehsarchive.html). Potential human health impacts include: cancer, Type II diabetes, behavioral changes such as increased aggressiveness and decreased attention span, compromised immunity, and neurological effects (Spano, T., “Contaminants of Emerging Concern: Endocrine Disruptors,” Presentation to COG Chief Administrative Officers Committee, August 1, 2007). It has also been suggested that EDCs may cause lowered sperm counts in humans, and abnormalities in male sex organs. There is clear evidence that exposure to EDCs result in adverse health impacts on non-humans and many scientists therefore caution that we must invoke the precautionary principal when considering the potential impacts on humans. In fact, the World health Organization states:
“…the biological plausibility of possible damage to human reproduction from exposure to EDCs seems strong when viewed against 1) the background of known influences of endogenous and exogenous hormones on many of the processes involved, and 2) the evidence of adverse reproductive outcomes in from wildlife and laboratory animals exposed to EDCs. The biological plausibility and the striking changes in human reproductive health trends in some areas, for some outcomes, are sufficient to warrant concern and make this area a research priority….there is biological plausibility and some experimental evidence that EDCs may contribute to hormonally influenced human cancer…” (Damstra, T., Barlow, S., Bergman, A., Kavlock, R., and Van der Kraak, G. (2002). “Global Assessment of the State-of-the-Science of Endocrine Disruptors,” WHO publication No. WHO/PCS/EDC/02.2, pages 69 and 86).
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