Just when you thought it was safe to drink the water, look no further than your medicine cabinet. Concerns continue to build over the public health impact of our water supply.
What are common chemicals/classes of EDCs?
According to the National Institute of Environmental Health Sciences (NIEHS), chemicals/classes of endocrine disruptors include “pharmaceuticals, dioxin and dioxin-like compounds, polychlorinated biphenyls, DDT and other pesticides, and plasticizers such as bisphenols (2011).” Disturbingly, endocrine disrupting chemicals (EDCs) can be found in literally thousands of common products including plastic bottles, metal food cans, detergents, flame retardants, food, toys, cosmetics, and pesticides (NIEHS, 2011). The broad presence of EDCs in everyday products increases the likelihood for interference with the body’s endocrine system to produce a number of adverse developmental, reproductive, neurological, and immune effects (NIEHS, 2011). While the field of endocrine disruption is fairly new, studies are being conducted to confirm whether endocrine disruptor exposure may reduce fertility and increase the incidence of endometriosis and some cancers (NIEHS, 2011). The future of this field will undoubtedly yield some extraordinary findings to ultimately increase the public’s awareness and impact future manufacturing processes.
How do EDCs get into receiving water bodies?
Endocrine disruptors infiltrate receiving waterways via personal, pharmaceutical, and agricultural applications. Human activity, residues from pharmaceutical manufacturing and hospitals, illicit drugs, and veterinary drugs contribute a variety of pharmaceuticals and personal care products (PPCPS) to receiving waters in the form of prescription and OTC therapeutic drugs, veterinary medicines, fragrances, cosmetics, sun-screen products, diagnostic agents, and vitamins (EPA, 2010). Agricultural applications also supply receiving waters with a plethora of chemicals suspected of acting as endocrine disruptors including insecticides, herbicides, fumigants and fungicides (NRDC, 1998). Individuals supply wastewater treatment plants with PPCPs through excretion, bathing, and disposal of medications into the sewer system and trash (EPA, 2010). Discarding unused medications and personal care products into the toilet is an irresponsible yet common practice that exacerbates the problem. Since PPCPs do not easily dissolve or evaporate at typical temperatures and pressures, they can infiltrate soils and aquatic environments with ease (EPA, 2010). PPCPs that are not broken down and processed by the body or degraded by the environment enter domestic sewers and remain untreated. PPCPs also have the capacity to penetrate soil and aquatics via sewage, biosolid applications, and irrigation with reclaimed water (EPA, 2010).
Endocrine disruptors are also introduced through spray-drifts, runoff from livestock and pesticides, and leachate from municipal landfills and septic systems (Center for Biological Diversity, n.d.). The widespread use of steroid hormones in confined animal feeding operations (CAFOs) is of particular concern for the introduction of endogenous steroids, exogenous compounds, pharmaceuticals, and anabolic growth promoters like trenbolone and melengestrol into receiving waters (Kolodziej, n.d). The potential for CAFOs to elevate the concentration of steroids in watersheds is considerably higher with the occurrence of extreme precipitation. The presence of synthetic steroid hormones such as trenbolone, melengestrol, and zeranol, used to promote rapid livestock growth, increases when the accumulation of animal wastes is not controlled and a direct pathway for wastes to reach surface waters exists (Kolodziej, n.d.).
Why are EDCs of particular concern to regulators?
Since municipal sewage treatment plants are not equipped for the removal of PPCPs and other unregulated contaminants, the presence of endocrine disrupting chemicals (EDCs) in the watershed poses a number of public health concerns. While the measure of health risks has yet to be quantified, growing evidence suggests that EDCs can produce adverse health effects in humans, wildlife, fish, or birds including developmental, reproductive, neural, and immune problems (EPA, 2010). This can adversely affect fish ecology and threaten the survivability of species. A panel of experts convened by the NIEHS and the National Toxicology Program (NTP) found ‘credible evidence’ for the effect of hormone-like chemicals on test animals’ bodily functions at levels below the ‘no effect levels’ established by traditional testing (EPA, 2010). There is also substantial research in experimental animals and wildlife associating EDCs with reduced male fertility and number of males born, male organ defects, female reproductive diseases, and increases in mammary, ovarian, and prostate cancers (EPA, 2010). The storage of endocrine disruptors in fat cells can also have long-term negative health consequences. Exposures to Bisphenol A and other EDCs with estrogenic activities increase the detrimental health effects of cancer and obesity (EPA, 2010). The transgenerational effects of EDCs is also a focus of study as NIEHS research has found that fertility defects have been passed to subsequent generations (EPA, 2010).
With the omnipresence of Bisphenol A (BPA), Di (2-ethylhexyl) phthalate, and phytoestrogens in many common, everyday products, the simultaneous exposure to multiple EDCs elevates concerns (EPA, 2010). As of 2007, over 100 individual PPCPs have been identified in addition to antibiotics and steroids that have been found in both environmental samples and drinking water. Simultaneous exposure occurs through one’s diet and the medications and cosmetics used. Studies are now focusing on the association between EDCs and resistance to antibiotic drugs as well as special scenarios involving fetal exposures (EPA, 2010). Further studies are warranted to investigate the acute and long term effects of EDCs as it remains a pressing and highly controversial public health issue.
Considerations for regulating EDCs in wastewater and/or receiving water bodies
Prior to designing regulations, policy-makers must consider scientific uncertainties associated with EDCs and their potential health effects in animals and humans. Stringent regulations must rely on a definitive classification system for endocrine disrupting chemicals so as to implement appropriate restrictive measures. The regulation process necessitates further research to identify conclusive evidence to considerably minimize the controversy that surrounds this issue. This will require the expertise of a broad variety of experienced medical scientists and environmental health specialists along with substantial research investment capital and time for further research completion. The implementation of appropriate regulations should reflect a close collaboration between policy makers, field experts, and the public at large.
Policy makers must also consider the level of vulnerability of the population exposed to EDCs and their potential impacts when implementing regulations. This can be based on a variety of factors including the average age, diet, occupation, and prevalence of obesity, cancers, and metabolic diseases. Other factors include the presence of major industries within a relevant geographical area. Infants, young children, and the elderly are special populations who exhibit increased susceptibility to EDCs due to inferior immune systems. Special considerations must also be considered for pregnant women and individuals with immune disorders/diseases such as AIDS. Obese individuals and people suffering from cancer are of particular concern as increased EDCs exposure can manifest or exacerbate symptoms associated with endocrine system abnormalities. One’s occupation is also a critical factor as manual laborers face increased frequencies and durations of EDC exposure. The presence of industries and the type of manufacturing processes and chemicals used are especially pertinent when initiating regulatory legislation to decrease the overall prevalence of EDC exposures among workers and citizens in the environment in which they live. Regulations should therefore reflect all of these factors to minimize the overall risk to any given population.
The potential impacts on businesses should also be considered. In a fragile American economy, the development of new restrictions would pose increased financial and administrative burdens, threatening the survivability of businesses. The alteration of manufacturing and agricultural processes to incorporate new raw materials to eliminate or reduce the release of EDCs could pose considerable financial losses. Similarly, provisions that necessitate wastewater treatment to improve levels of EDCs in effluent discharges or measures to decrease employee exposure could prove to be exceedingly costly. Also, company management plans for the monitoring of EDCs would necessitate comprehensive recordkeeping and reporting, requiring additional manpower and staff.
Kolodziej, Edward. (n.d.) University of Nevada, Reno. Occurrence, fate, and transport of steroid hormones. Retrieved from http://www.unr.edu/cee/homepages/kolodziej/research.html
Miller, Jeff. Center for Biological Diversity. (n.d.). Endocrine disruptors. Retrieved from http://www.biologicaldiversity.org/campaigns/pesticides_reduction/endocrine_disruptors/index.html
National Institute of Environmental Health Sciences (NIEHS) (n.d.). Endocrine disruptors. Retrieved from http://nymc.mrooms.org/file.php/264/Session_15_Readings/Endocrine_Disruptors_-_intro.pdf
National Institute of Environmental Health Sciences (NIEHS) – National Institutes of Health.(2011). Endocrine disruptors. Retrieved from http://www.niehs.nih.gov/health/topics/agents/endocrine/index.cfm
National Resources Defense Council (NRDC). (1998). Endocrine disruptors. Retrieved from http://www.nrdc.org/health/effects/qendoc.asp