Water: safe to swallow?
If all the water on earth could fit in a gallon jug, and if you poured out the portion that was non-drinkable (too salty, polluted, or hard to get), you'd end up with one single drop. Is that drop safe to drink? Not if you happened to be in Des Moines, Iowa on September 27, 1983. On that day, levels of trichloroethylene (TCE)--a suspected carcinogen--soared to more than 18 times the current federal limit. In fact, throughout the late 70s and early 80s, the 190,000 residents of Des Moines routinely drank water with anywhere from two to ten times the amount of TCE now permitted.
THERE'S MORE TO WATER THAN [H.sub.2] O
How did this hazardous solvent get into the municipal water system? A local company used it in the 1960s to remove grease from metal wheels and brakes. The firm disposed of the oily waste by spraying some of it on the parking lot (for "dust control") and by dumping the rest into a nearby drainage ditch.
Now your water might not be as bad as Des Moines' was. Then again...
The sad truth is that your drinking water could contain any of nearly 1,000 contaminants. Sadder yet, the Environmental Protection Agency (EPA) has set enforceable limits for just 30 of the 1,000. (There was none for TCE back in 1983.) What's more, many of those 30 limits were established years ago, and are considered too high by today's standards.
Consider The Source. Rivers, lakes, and reservoirs supply about half the population, including most major cities. On the way to the purification plant, this "surface" water can pick up some unsavory companions: pollutants from industrial discharges, mining wastes, pesticide runoff from farms or roads.
The rest of us drink "ground" water, which comes from slow-moving, underground "rivers" that feed our wells and springs. Ground water supplies 97 percent of all rural households, portions of about 20 major cities (including Los Angeles, New York, and Spokane), and most of Florida. It can become contaminated from leaking municipal landfills, underground gasoline storage tanks, hazardous waste storage or disposal sites, or septic tanks.
Meet The Pollutants. The list of 1,000 contaminants identified by the EPA reads like a Who's Who of environmental pollutants: bacteria, benzene, lead, mercury, PCBs.
Some of the 1,000 even come from our attempts to purify the water supply. Surface water often contains decaying leaves or other plant or animal matter. When this water is treated with chlorine (as nearly all surface water is), cancer-causing compounds can form.
In 1987, a major study by the National Cancer Institute (NCI)(1) concluded that the risk of developing bladder cancer rose with increased intake of beverages made with chlorinated surface water--which is what comes out of the tap in about half the households in the U.S.
"We estimate that chlorinated surface water is responsible for about a quarter of all bladder cancer cases among non-smokers, if the relationship is causal," says study co-author Robert Hoover.
Bladder cancer primarily affects the elderly, and is the fifth most common cancer in the U.S. Its incidence has increased by more than 50 percent since 1950.
The NCI is now looking for a link between chlorinated surface water and other types of cancer--something the first study wasn't designed to detect.
Get The Lead Out. Both surface and ground water can pick up an unwanted passenger on the trip from the purification plant to the tap: lead.
Lead can raise blood pressure, cause babies to be born premature or underweight, and impair the mental abilities of children. The Centers for Disease Control estimates that 10.4 million children in the U.S. are exposed to significant amounts of lead in their drinking water.
"The more we learn about lead, the more we find adverse effects at lower and lower levels," says Joel Schwartz, senior scientist at the EPA. "Drinking water is now a major source of lead for a sizeable portion of the population. It's a matter of considerable concern."
If your home has lead pipes, or has copper pipes with lead solder that were installed less than five years ago and your water is acidic, you could be ingesting high levels of lead. The only way to know for sure is to have your water tested.
Meanwhile, minimize exposure by sticking to the "C" tap for drinking and cooking (let it run until it gets as cold as it's going to, which could take a few minutes if you haven't used any water or flushed a toilet for several hours).
EPA To The Rescue? The EPA requires your utility to keep your water below the Maximum Contaminant Levels (MCLs) for just 30 potential pollutants.
In 1986 Congress ordered the EPA to increase the number of regulated contaminants from 30 to 83 by June of 1989. Needless to say, things are already behind schedule.
"I just can't believe how little the EPA has accomplished in the last 14 years," says Ned Groth, associate technical director of Consumers Union.
The National Wildlife Federation (NWF) goes even further. A report released in early October charges that "millions of Americans are drinking unsafe water."(2)
The NWF claims that public water systems committed more than 100,000 violations of the Safe Drinking Water Act in 1987. What's more, says the environmental group, the water utilities broke the law "94 percent of the time," by failing to inform consumers when violations occurred.
Your Right To Know. Your water provider must give you the results of its testing...if you ask. This will cover the 30 contaminants that are regulated, up to 36 others that must (eventually) be monitored, plus any additional ones your state requires.
Once you know how much of what is in your water, find out how much is too much, by calling the EPA Safe Drinking Water Hotline at (800) 426-4791 (382-5533 in Washington, D.C.). Ask for a list of finalized and proposed federal standards, as well as any "health advisories" or guidelines for contaminants that have no standards.
Pay particular attention to the level of "total trihalomethanes" (THMs), which are the contaminants most clearly related to your risk of developing bladder cancer. According to the National Academy of Sciences, the EPA's standard of 100 micrograms per liter (mcg/l, or ppb) is too high.(3) We suggest a level of 10 mcg/l.
Testing, Testing. You should consider going through the expense of testing your tap water if: * You drink from your own well or other private water supply. * You notice a change in your water's color, taste, or odor. (Some utilities will do free sampling at your tap.) * You suspect the presence of lead. (Make sure the lab can detect levels down to 10 parts per billion.) * Your water company serves fewer than 3,300 people. If so, it doesn't have to comply with new monitoring requirements as quickly as larger systems. * You live near a hazardous waste dump, industrial park, chemical manufacturing plant, military base, or non-organic farm.
If you decide to test, call the EPA Safe Drinking Water Hotline for the name of the drinking water laboratory certification officer for your state. He or she should be able to give you a list of approved labs.
Since there are hundreds of potential pollutants, try to narrow the field before testing. Under the Emergency Planning and Community Right-To-Know Law, you can obtain information about hazardous chemicals (but not pesticides) in your community.
Home Treatment. Home filters can make a difference...if you know how to select and maintain them. If you don't, they can actually increase contaminant levels.
A good overview of existing systems can be found in Is Your Water Safe To Drink? by Raymond Gabler and the editors of Consumer Reports Books.
Is Bottled Better? If sales figures were synonymous with health value, bottled water would be as pure as the TV commercials suggest.
Americans spent $1.5 billion on an estimated 1.25 billion gallons of bottled water in 1987, according to the International Bottled Water Association (IBWA). "One out of six households now uses bottled water as its primary source of drinking water," says IBWA executive vice president William Deal. The industry group claims that in California the figure is one out of three.
The IBWA is careful not to make any health claims for bottled water, but it's clear that the industry profits from the perception that bottled is better.
As far as federal authorities are concerned, bottled water currently has to meet standards for only 22 contaminants: eight fewer than for tap water. And, the Food and Drug Administration doesn't even have a monitoring program to see if that's being done.
"If no one looks, no one finds," says Sandra Marquardt of Greenpeace, co-author of a forthcoming Environmental Policy Institute report on bottled water.
Mineral and soda waters, which are used by millions of people as their main source of drinking water, don't even have to meet the same quality standards as other bottled water. * A 1987 state survey revealed that 13 of 15 brands of mineral water sold in Massachusetts exceeded one or more federal or state guidelines. * A New York survey found traces of toluene, carbon tetrachloride, and other solvents in 48 of 93 bottled waters sampled last year. * A British study found high levels of bacteria in 20 of 29 non-carbonated mineral waters.(4) * Researchers at Northeastern University discovered several kinds of antibiotic-resistant bacteria in 6 of 8 brands of bottled spring and distilled water purchased in the Boston area.(5)
Not only is bottled less regulated than tap; sometimes bottled is tap. "Drinking water" on the label probably means tap water inside the bottle. The tap also can provide the raw material for "purified," "distilled," "soda," "club," and even some "mineral" waters. The exception is "spring" water, which should come from an underground source. But even that's no guarantee of purity.
So is bottled better? Some probably is...and some definitely isn't.
One thing you can do is ask the bottler for the latest test results for all the chemicals it checks for. Then compare the numbers to the standards or guidelines you get by calling the EPA hotline.
You might or might not learn something. Poland Spring sent us test results for only 15 contaminants, Great Bear gave us 17, Evian sent 24, and Mountain Valley sent 51. After some convincing, Perrier gave us test results for 93 contaminants. It normally sends 12. None of the contaminant levels provided by the bottlers exceeded federal standards.
What It All Boils Down To. There is no clear winner in the Water Derby. Tap, filtered, or bottled--each has its own risks.
Even boiling regular tap water (which kills germs) can end up concentrating the contaminants it doesn't remove.
One safe (but not particularly palate-pleasing) choice is to boil distilled water. Distillation gets rid of chemicals with a boiling point greater than water, while boiling takes care of most of the rest, as well as bacteria and other biological contaminants.
It's not going to win any taste tests, but you probably won't notice the difference if you use it to make juice or tea.
And since distilled water has no minerals, you should be particularly careful to eat foods rich in calcium and magnesium (dairy products, whole grains, and vegetables).
(1)J. Nat. Cancer Inst. 79:1269, 1987. (2)National Wildlife Federation (Washington, D.C.), Danger on Tap, 1988. (3)National Academy of Sciences (Washington, D.C.), Drinking Water and Health: 7, 1987. (4)Epid. Infec. 99:439, 1987. (5)Can. J. Microbiol. 33:286, 1987.
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|Title Annotation:||includes related article|
|Author:||Schmidt, Stephen B.|
|Publication:||Nutrition Action Healthletter|
|Date:||Nov 1, 1988|
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