The following blog was submitted by Colin Richards, a PhD student in CEE, as part of the requirements for GRAD 5414 Water for Health Seminar Interdisciplinary Seminar. This course examines emerging interdisciplinary issues related to the chemistry, microbiology, engineering and health aspects of drinking water.
Endocrine disrupting chemicals (EDCs) in potable water was the topic of the presentation given by students (Emily Garner, Laura Nelson, and James Wade) in the Virginia Tech Water for Health Seminar (GRAD 5414). EDCs are a broad class of contaminants of emerging concern that are characterized by their ability to mimic hormones, thus affecting our endocrine system. The adverse health effects of EDCs at levels found in drinking are open for debate though some studies have shown that they may contribute to early onset of puberty and increased risk of breast cancer (Birnbaum 2010). The presenters supported the idea of regulating EDCs in our potable water. While it was convincing that EDCs need to be regulated, the process of doing so will not be an easy or straightforward task.
EDCs were first recognized as a potential problem in 1996 when the Safe Drinking Water Act was amended to require the Environmental Protection Agency (EPA) to conduct a screening program. The original goal was to screen pesticides for estrogenic effects but it was later expanded to include chemicals with androgenic and thyroid effects as well as potential impact on wildlife (USEPA, 2014). The screening program has since identified around 10,000 chemicals that may exhibit these effects though it is unlikely they will all be screened. The screening order will prioritize the chemicals based on potential toxicity and exposure.
The EPA screening program, however, does not regulate EDCs in our drinking water. Before a chemical is regulated, it goes through a lengthy process where eventually a maximum contaminant level (MCL) is established. During this process, a contaminant candidate list (CCL) is created every five years for chemicals whose regulation is under consideration. The CCL4 was drafted in 2015 by EPA scientists; among the 100 chemicals listed are several EDCs (USEPA, 2015).
There are several factors that go into determining how a chemical moves from the CCL to being regulated. Some of these factors make it problematic to regulate EDCs as a whole. Conducting toxicity studies for every suspected EDC is simply too expensive and time consuming. Detecting EDCs is another issue. Monitoring for every EDC once a regulation is set puts a heavy burden on public utilities. Finally, reliable treatment methods need to be available for utilities once a regulation is set. There is no single reliable treatment strategy for every EDC identified. Novel treatment techniques such as advanced oxidation is highly effective in removing many EDCs but few utilities are equipped with such technology (Rosenfeldt and Linden, 2004). Given the nature of the regulating process, it is easier to regulate individual EDCs than EDCs as a whole. In the meantime, the World Health Organization and United Nations Environment Program has released a report calling for global cooperation in EDC research (WHO/UNEP, 2013). Efforts such as this will accelerate the regulation process in the U.S.
Birnbaum, L. S. (2010). Endocrine Disrupting Chemicals in Drinking Water: Risks to Human Health and the Environment. Retrieved from http://www.hhs.gov/asl/testify/2010/02/t20100225a.html.
King County, Washington. (2015). Endocrine Disrupting Chemicals in the Environment. Retrieved April 24, 2015, from http://www.kingcounty.gov/environment/wtd/Education/EmergingIssues/EDC.aspx
Rosenfeldt, E. J., & Linden, K. G. (2004). Degradation of endocrine disrupting chemicals bisphenol A, ethinyl estradiol, and estradiol during UV photolysis and advanced oxidation processes. Environ. Sci. Technol. 38(20), 5476–5483. doi:10.1021/es035413p
United States Environmental Protection Agency. (2014). Endocrine Disruptor Screening Program (EDSP). Retrieved April 23, 2015, from http://www.epa.gov/endo/
United States Environmental Protection Agency. (2015). Chemical Contaminants – CCL4. Retrieved April 23, 2015, from http://www2.epa.gov/ccl/chemical-contaminants-ccl-4
World Health Organization and United Nations Environment Programme. (2013). State of the Science of Endocrine Disrupting Chemicals – 2012. Geneva, Switzerland: WHO/UNEP. Retrieved from http://www.who.int/ceh/publications/endocrine/en/