Endocrine Disruptors in the Catawba River
by Ben Lemmond
Endocrine Disruptors: A Quiet Threat to the Catawba River
According to regional environmental agencies (NCDENR, SCDHEC), the presence and/or impact of endocrine disruptors in the Catawba River basin has yet to be studied. However, considering the abundance of known sources of these chemicals in the Catawba and the overwhelming abundance of evidence of endocrine-disrupting problems in other rivers, including several rivers in the Southeast (the Apalachicola–Flint–Chattahoochee, the Savannah, and the Pee Dee), it is very likely that such chemicals would be found at biologically significant concentrations in the Catawba River. Furthermore, the population explosion and development along the Catawba River Basin makes the Catawba a great candidate for in-depth studies of: a) the effects of certain patterns of population growth and development on concentrations of endocrine disruptors in the River, and b) the resulting impact of endocrine disruptors on the populations (wildlife and human) that the River sustains.
Contributors of endocrine disrupting chemicals to our River:
-
Wastewater
Wastewater is perhaps the most significant contributor of a variety of endocrine disruptors to the water, especially in the case of rivers situated along large urban areas. The Catawba receives an average of 81.30 million gallons a day (MGD) of treated wastewater effluent from the Charlotte region alone. Treated wastewater contains numerous EDCs: natural and synthetic hormones (such as the birth control hormone) that are excreted from our bodies, triclosan, an ingredient in most antibacterial hand soaps, BPA, phthalates, surfactants, and other contaminants. Many of the studies on intersex fish have observed higher rates downstream from wastewater treatment outfalls; others have used treated wastewater in a laboratory setting to demonstrate its endocrine disrupting potential.
Most wastewater treatment facilities were not designed to remove these contaminants from water. The method that Charmeck Utilities uses for wastewater and drinking water treatment, which is called "flocculation-sedimentation" (with additional chlorine disinfection for drinking water), has been ranked among the "least effective" methods for removing these contaminants by a study that compared various wastewater treatment methods in this context. Reverse osmosis, nanofiltration, activated carbon, advanced oxidation processes and high-energy ultraviolet irradiation at oxidative doses are treatments that are considered to be much more effective at removing EDCs from water.
Similarly, septic systems can contaminate groundwater with natural and synthetic hormones, which are not removed or changed in the treatment process.
Since the endcorine disruptor exposures to humans through drinking water are unlikely to be as serious than environmental exposure (exposure through food, plastics, etc), there has been little effort to retrofit water treatment facilities with technology that would more effectively remove chemicals from treated water. However, wastewater is the main source of the chemicals that have caused feminized fish and other endocrine-related effects in river and stream ecosystems. Until wastewater treatment is brought up to speed with these emerging contaminant concerns, fish and aquatic ecosystems will continue to suffer from the effects of endocrine disruptors in their environment.
-
Stormwater
Since the 1990’s, the United States Geological Survey began nationwide surveys of the waters in the U.S.. Samples were analyzed for pesticides, herbicides, fungicides, and pharmaceutical/personal care products (PPCPs). Results from these surveys show unequivocally that very few of our waters remain untouched by our synthetic chemical footprint: in the first five years of sampling, at least one pesticide or pesticide byproduct was detected in 100% of fish and 99% of streams sampled in urban areas, and 85% of fish and 92% of streams in agricultural areas.
Stormwater runoff is responsible for facilitating the widespread contamination of these streams. With each heavy rain or flood, weed killer, bug spray, and other common lawn and garden products are flushed untreated into nearby streams, and eventually to the river. Contaminants from roads and highways are also washed directly into streams and rivers via stormwater. Stormwater, unlike wastewater, is not treated in any way.
One of the few water quality studies of the Catawba River Basin (relevant to the issue of endocrine disruptors) was conducted as part of the USGS National water Quality Assessment (NAWQA) program. Beginning in 1994, the Catawba and Santee Basins (downstream of the Catawba) were sampled for pesticide pollution. In a decade of testing, the herbicides atrazine, simazine, and tebuthiuron were detected in almost every stream sampled in the Santee Basin, including those in forested areas. Four common insecticides—malathion, diazinon, chlorpyrifos, and parathion—exceeded EPA’s guidelines for aquatic wildlife toxicity, which do not yet account for the possibility of endocrine disruption. However, more than a third of the pesticides detected had no aquatic toxicity guidelines (13 out of 30). This evidence suggests that pesticide contamination is common in this region, and that adequate guidelines have not been established for all of the chemicals found in the water - not to mention, a guideline or standard accounting for possible additive or synergistic effects of these chemicals. Increasingly, these chemicals are found in our nation's water supply. A recent New York Times article exposes some of the disturbing trends of Atrazine, a widely-used herbicide, in the water supply.
Other persistent pollutants, such as DDT are still regularly detected in the environment and in living organisms. In fact, the USGS reported that these persistent pesticides were "detected frequently in bed sediment and tissue" in this river basin. Even though many of these substances have been banned for decades since the program began, the levels of one of these chemicals (DDE) exceeded aquatic toxicity guidelines in three sampling sites.
-
Other Sources
Other potential sources of endocrine disruptors in the Catawba River include leachate from landfills (which contains BPA and other plastic residues), and residual pollutants from chemical and industrial operations along the River. For many decades, the Carolinas were a hotspot for the textile industry. In order to supply the textile industry with dyes, fixatives, bleaching agents, and other chemicals, numerous chemical companies were established in the Catawba and Santee River basins. Many of these chemicals are highly persistent in the environment, and residual contamination may still occur at low levels.
Bad Habits
Although the issue of endocrine disruption is relatively new, and filled with intricacies and difficulties with which we have little experience, the questions brought up by this issue of low-level exposure to endocrine disruptors are some of the familiar and fundamental questions of toxics regulation: Is our regulatory system adequately protecting our health? Can we reduce exposure to toxic chemicals without major economic consequences? Are small exposures to toxic chemicals truly safe? Generally, our answers to these questions in the past reflect a pervasive skepticism of major change regarding chemical use and a permissive attitude towards chemical exposure. Major assumptions, such as the assumption that even the most toxic pollutants can be sufficiently diluted, need to be examined critically, in the light of emerging evidence of harm from low-level exposures to chemicals such as endocrine disruptors. Yet even some of the basic steps to protect ourselves and our environment from harmful substances have yet to be taken.
Consider this: the EPA admits that of all the chemicals that the US imports in quantities greater than 1 million pounds per year, around 3,000 chemicals total, 93% of them are missing one or more important toxicity tests; 43% have no basic toxicity testing data at all, and only 7% have a full set of basic test data. In another study of a set of 491 chemicals used in household products or children's products, the EPA found that only 25% had basic toxicity testing data. The EPA concluded that "Most Americans would assume that basic toxicity testing is available and that all chemicals in commerce today are safe. [This] study has found that this is not a prudent assumption."
Instead of preventing potentially harmful chemicals from being on the market, we have fallen into a dangerous habit of allowing chemicals to enter the market untested - only to discover, in many cases many years too late, that some of these chemicals are harmful.
The tendencies and habits that lie at the heart of this kind of universal chemical exposure can and should be questioned by everyone – citizens, scientists, manufacturers, and legislators alike. For issues that concern the Catawba River - like endocrine disruption and all the issues that fall under its umbrella: pesticide use, inadequate wastewater treatment, coal-fired power plants, our daily inundation with synthetic chemicals and materials - everyone in this region has a stake in the outcome.
How You Can Help the River:
- Minimize pesticide/herbicide use in your own home and garden
- Support agricultural practices that do not use synthetic pesticides or herbicides
- Use natural cleaning products (which are less likely to contain synthetic surfactants, several of which are known endocrine disruptors)
- Always properly dispose of hazardous chemicals and cleaning products: anything you flush or pour down the drain may end up in the river. For information on how to dispose of hazardous waste (for free), click here.
- Remember that other people and animals need the river to stay clean – treat it well!
How You Can Reduce Your Exposure to EDCs
- Know what's in products you use! But to begin with:
- Avoid drinking from polycarbonate plastic containers, which leach BPA, especially when heated.
- Reduce your consumption of canned food, which contains BPA that has leached from the lining inside the can.
- Reduce soft vinyl plastic in your environment. Soft vinyl toys, shower curtains, and school supplies (lunchboxes, etc) can contain >50% phthalates by weight.
- Support BPA bans and other EDC-related legislation
- Reduce fish, dairy, and meat consumption. For information on the North Carolina fish consumption advisory, click here - for SC's fish advisory page, click here
Return to Other Pages:
