Unintended Effects of Water Purification

While it should be said that given the contamination of natural water sources from which municipalities must depend, they do a relatively good job of sanitizing and delivering consumable water to homes. However, because of the challenges that they face in treating contaminated water, unintended health and environmental effects are being realized more and more every day.

Infrastructure

The chemicals used in pipes, and joints, may contaminate drinking water after it has been treated. This may happen from the connecting joints in municipal pipes, leaks within those pipes, or where workers tapped into the pipes for repair. The many different materials used in water delivery systems result in varied contamination sources. Copper, tar, asphalt iron, zinc, coal, polyethylene, concrete, polyvinyl chloride, vinyl, asbestos and lead are all possible sources of post-treatment, contamination. Another recent study showed an association between leukemia and trichlorethylene, which came from plastics used in the drinking water delivery system. A historical study of several water systems demonstrated an increase in the cancer causing properties of drinking water after passing through the water delivery system.

Lead can enter the water supply as it leaches from copper pipelines. The construction industry used lead solder in piping all the way up until 1988. As the water streams through the pipes, small amounts of lead will dissolve in the water, so that it becomes contaminated. Lead is a toxic substance that can be quickly absorbed in the human systems, particularly those of small children, and can result in lead poisoning.

The same chemicals used to treat water for sanitation have also been found to corrode the insides of these pipes over time. The long-term effect of this corrosion is pinhole leaks that can form in the pipeline over time. If these leaks occur in pipes inside the home, costly structural damage, mold infestation, and water waste could be experienced. Homeowners or water professionals should perform a simple check for leaks by shutting off all faucets and other water outlets in the home, then checking to see if the water meter is still running. That can indicate a leak problem.

Human Health

University of Illinois geneticist Michael Plewa said that disinfection by-products (DBPs) in water are the unintended consequence of water purification. "The reason that you and I can go to a drinking fountain and not be fearful of getting cholera is because we disinfect water in the United States," he said.

The process of disinfecting water with chlorine and chloramines and other types of disinfectants generates a class of compounds in the water that are called disinfection by-products. The disinfectant reacts with the organic material in the water and generates hundreds of different compounds. Some of these are toxic, some can cause birth defects, some are genotoxic, which damage DNA, and some we know are also carcinogenic.¹

A 10-year study by the University of Illinois Genetics department, funded by a grant from the EPA, was intended to develop mammalian cell lines that would be used specifically to analyze the ability of these compounds kill living cells, and the ability of these emerging disinfection by-products to cause genomic DNA damage.

This study assembled the largest toxicological database on these emerging new DBPs known to date. The study made two fundamental discoveries that have a great impact on human health.

The first discovery involves iodine-containing DBPs. Iodine comes primarily from seawater or underground aquifers. When common municipal disinfectants are used in water that is high bromine and iodine, the chemical conditions necessary to produce DBPs are created. These are much more toxic and genotoxic than the levels of DBPs that the EPA currently regulates.

The second discovery concerns nitrogen-containing DBPs. Disinfectant by-products that contain nitrogen are far more toxic and genotoxic, and some even carcinogenic, than those DBPs that don't have nitrogen. Again, there are no nitrogen-containing DBPs that are currently regulated by the EPA.

Furthermore, studies were showing higher levels of bladder cancer and asthma in people who do a lot of swimming - professional swimmers as well as athletic swimmers. These individuals have greater and longer exposure to toxic chemicals, which are absorbed through the skin and inhaled. Although at lower levels because organic material from humans is not as prevalent in source water for drinking as in swimming pools, prolonged skin exposure to treated water, such as when showering or bathing, may have similar long term effects. The solution is to keep the pools disinfected and in compliance, just as with drinking water, but then use point-of-use filtration methods that reduce the levels of these toxic by-products.

Environmental Health

The treatment of municipal water has also been shown to have adverse effects on our environment.

The toxic environmental effects of fluorides are also well documented.² Airborne fluoride pollution from industrial sources may cause severe effects in plants by inhibiting photosynthesis, chlorophyll production and carbohydrate metabolism, with resulting defoliation or death.

As a water pollutant, elevated concentrations of fluoride may affect a number of organisms, including fish, amphibians, insects, snails, shellfish, protozoa, and some aquatic plants. Fresh water fish, especially rainbow trout and other trout species, appear to be particularly sensitive and may show growth and behavioral changes, decreased survival, and prolonged hatching time when exposed to moderate levels. Generally speaking, fluoridated water loss during use, dilution of sewage by rain and ground water infiltrate, fluoride removal during secondary sewage treatment, and diffusion dynamics at effluent outfall combine to eliminate fluoridation-related environmental effects.

An emerging issue in the treatment of drinking water is the role played by chlorine in the formation of toxic compounds. Chlorine as a disinfectant to natural waters can result in the formation of chloroform and other carcinogenic or mutagenic compounds. Chloroform is a known animal carcinogen.³

¹ Plewa, Michael, What's in your water?: Disinfectants create toxic by-products, University of Illinois.

² John W. Osterman, MD, ScD, Evaluating the Impact of MunicipalWater Flouridation on the Aquatic Environment, American Journal of Public Health, October 1990.

³ Ronald E. Rathbun, Potentially Deleterious Effects of Chlorinating Mississipi River Water for Drinking Purposes, US. Geological Survey Circular, 1995.