Industrial Solvent in Drinking Water
In the News.
Public Health and Drinking Water News Briefs
The drinking water in some Ontario communities has been found to contain high levels of trichlorethelene (TCE), a toxic industrial solvent, provincial water quality disclosure records show. Tens of thousands of people have been exposed to the compound in recent years at levels considered risky in the United States.
TCE is commonly used to degrease metals. Exposure to high levels of it is associated with leukemia and cancers of the cervix, prostate and colon, among others. It's dangerous to drink water containing TCE and risky even to bathe or shower in it because of the vapour.
The town of Beckwith, near Ottawa, had the worst results: TCE levels last year exceeded outdated provincial standards. Barrie, Cambridge, Fergus, Orangeville and Orillia were among towns whose water levels of TCE were near or exceeded the US TCE safety standard in 1998 and 1999 tests.
Ontario's TCE safety standard allows 10 times the amount permitted in the US. There, the deaths of 12 children were blamed on the chemical in a tragedy that inspired the novel and Hollywood film, A Civil Action. The Sierra Legal Defence Fund is demanding Ontario adopt the US standard of five parts per billion of TCE in drinking water.
--Globe and Mail, March 21, 2001
Questioning Water Safety
by author Rick de Vries
Studies undertaken in Europe, the United States and Canada have detected a wide range of pharmaceuticals and personal care products (PPCPs) in surface water, groundwater and even drinking water systems. PPCPs are basically all drugs such as antibiotics, steroids, antidepressants, narcotics, painkillers and tranquilizers. They also include oral contraceptives, antiseptics, fragrances, shampoos, sunscreens, insect repellents, food supplements, caffeine and nicotine, to name a few.
There are several ways this form of water contamination occurs. When you take a drug, a large percentage of it passes through the body unchanged. The body also converts some of that drug into other compounds called metabolites, which may be even more bioactive than the original drug. The combined result is excreted through urine and feces and ultimately ends up in waste treatment plants along with other personal care products that have been washed off the body. Most treatment plants are unable to remove PPCPs, so they pass into either surface waters (from the liquid portion) or groundwater (from the solid waste portion). Runoff from farm animal operations also contributes a significant amount of PPCPs to the environment, as do hospital discharges and the aquaculture industry.
The range of contaminants is staggering. German researchers have found up to 60 different drugs in their water samples. In their 30-state water sampling, the US Geological Survey has found 31 kinds of antibiotics and antibacterial chemicals, as well as a variety of hormones and birth control compounds.
We're not talking just small amounts of chemicals either. Thousands of tonnes are released into water annually, which is similar to the amount of fertilizers used by the agriculture industry. One startling example involves clofibric acid, a drug for reducing cholesterol levels. Estimates put the clofibric acid content in the North Sea at 43 to 66 tonnes, with an additional 50 to 100 tonnes flowing through every year!
Should We Be Concerned?
Yes. Little is known about how each component of this complex mix reacts with each other or the environment. There are simply too many chemicals to be able to predict what happens.
We don't know the long-term effects on humans and aquatic ecosystems. Some effects could be profound and readily visible; however, others could be so subtle that they may not be detectable for years.
At present, we have a long list of questions rather than facts. Consider the PPCPs found in drinking water samples. What are the long-term effects of drinking this chemical mixture every day? Musk (a fragrance used in detergents and perfumes) is fat-soluble and therefore accumulates in the fatty tissues of fish. What are the long-term effects of eating this fish? A pregnant woman risks the health of her developing fetus when she ingests chemicals. What are the effects on the fetus from the consumption of PPCPs in food or drinking water?
Hormones have also been detected in water samples. Could their continual ingestion be the cause of decreased fertility, cancers and other diseases? Some studies have indicated this may indeed be the case. In addition, the increased appearance of antibiotic-resistant bacteria is a matter of great concern among health-care professionals. Could the significant levels of antibiotics in water systems be a contributing factor? Some researchers say it is possible. The answer to all of these questions above and many more is that we simply do not know.
What We Do Know
Generations of aquatic organisms have lived and continue to live in this chemical soup. For them, there is no escape. Toxic exposure is constant and even low concentrations of PPCPs can have very significant effects on many species. The following are some examples:
· Synthetic estrogen in oral contraceptives can lead to the feminization of male fish and deformed sex organs in other species.
· Antidepressants can disrupt spawning behaviour in shellfish.
· Musk accumulates in the fatty tissues of aquatic organisms, which leads to bioaccumulation as it moves up the food chain.
· Certain cardiac drugs can prevent aquatic organisms from expelling contaminants from their systems, thus increasing the toxic effects of all the PPCPs they are exposed to.
The issue of PPCP contamination of water systems has only been recognized in the last 10 years. More extensive sampling programs have recently begun, and some effects on human and environmental health are beginning to be examined.
The magnitude of this problem and potential negative impacts definitely warrant further investigation. Contamination is extensive and exposure is continual. As long as wastewater treatment plants continue to pump out PPCPs, contaminants will always be present in water systems. Natural degradation of these chemicals can occur; however, new PPCPs continually flowing in results in no decrease in concentration and renders the existing treatment process ineffective. Perhaps before seeking an answer to the question of what PPCPs are doing to the environment, and us, we should look at how we can keep them out in the first place.
For more information, go the US Environmental Protection Agency's Web site at epa.gov/nerlesd1/chemistry/pharma/.
Rick de Vries is the co-publisher and editor of Fresh Outlook Magazine, which explores water and wastewater issues as well as related environmental topics. He has a background in biological sciences technology, specializing in pollution and environmental sciences.