The safety of our drinking water is often taken for granted in America. In recent years, however, environmentalists and the media have drawn attention to the dangers of ground water pollution and the health risks of lead, chlorine, pesticides, organic chemicals, and various microorganisms that have been found to contaminate our public water supplies. Outbreaks of waterborne diseases are a common occurrence and have involved entire city populations, sometimes leading to serious complications and even fatalities. The potential carcinogenic effects of long-term exposure to certain organic chemicals in our water supplies are under government scrutiny.

Sources of Water Pollution
from Is Our Water Safe to Drink?
J. Gorden Millichap, MD

Above is the opening paragraph from a new book, Is Our Water Safe To Drink? A Guide to Drinking Water Hazards and Health Risks,* by NOHA Professional Advisory Board Member J. Gordon Millichap, MD. He has given us an excellent summary of the health risks in our drinking water from pollutants such as microorganisms, toxic minerals, pesticides, radon, and radioactive waste. In every case, Dr. Millichap gives the sources of contamination, the symptoms and treatment, and ways to avoid or minimize our exposure. He explains systems and degrees of water treatment along with their advantages and limitations.

Following are a few vignettes:

Microorganisms: Viruses, Bacteria, and Parasites

Some microorganisms persist as cysts, e.g. Entamoeba histolytica. Asymptomatic cyst carriers are a major source of infection. Cysts are resistant to disinfectants and they can survive for weeks or months in a moist environment. The prevalence of infection is as high as 50 percent in underdeveloped countries and 5 percent in the United States. . . .Overcrowding and poor sanitation and hygiene have resulted in major waterborne outbreaks, including the Chicago Exposition in 1933, and the Singer Sewing Machine Plant in Indiana in 1950.

The examination of water samples for viruses takes a minimum or two weeks and the tests are not completely reliable. Bacteriological monitoring is used as the conventional indicator of potable water safety, but viruses are more resistant to water treatment processes than bacteria and may escape detection. Enteric viruses may be present in drinking water without signs of bacterial pollution. . . .

The examination of water samples for viruses takes a minimum or two weeks and the tests are not completely reliable.

The recycling of waste water for domestic use, now employed in some States with water shortages, may increase the risk of virus contamination. One large beer producer in Southern California, with serious doubts about the purity of the reclaimed water used in manufacture of its product, has filed a lawsuit in Los Angeles to stop the practice of recycling sewer water. . . . Since 80 percent of beer is water, breweries may have to conduct their own tests for viral, bacterial, and parasitic, as well as chemical contamination, so that jokes about "beer made from sewer water" can be dispelled.

Parasites are the most frequently identified cause of waterborne diseases in the United States. The 1993 outbreak of the parasite Cryptosporidium  affected almost half a million people and contributed to one hundred deaths in Milwaukee, Wisconsin. The outbreak resulted from the failure of the municipal filtration systems to eliminate animal wastes. The water rather suddenly became brownish. Cautious people would have immediately sought out bottled water. Dr. Millichap warns people to be alert to changes in their water—either flavor or appearance.

Bottled Water

Concerns about bottled water include the fact that the government regulations regarding it are often less stringent than those for public water systems. The former is controlled by the Food and Drug Administration (FDA) and the latter by the Environmental Protection Agency (EPA). Their regulations can differ somewhat. Dr. Millichap lists the government permitted contamination levels. Interestingly, one third of all bottled water sold in the United States is actually taken from a public water system. However, if the bottled water does come from a deep, protected acquifer, it is less likely to be contaminated than a public water system that is derived from surface water. "Upland surface water and polluted river sources that have been chlorinated carry the highest risk of cancer. Unchlorinated ground water has the lowest cancer risk."

When you use bottled water, choose glass bottles. Even when the water is from an excellent source, storing it in plastic causes contamination. "It may surprise consumers to realize the enormous potential for risk of intoxication from a multitude of migrant chemicals contained in plastic containers." Government regulation has reduced some of these risks. However, "a carcinogen, methylene chloride, may enter bottled water from the polycarbonate resin in certain plastic bottles, and bacteria may multiply during prolonged storage."

Water Treatment Plants

Aluminum and other additives

In water treatment plants coagulants are employed in order to increase the efficiency of filtration. "The use of aluminum and iron salts, sulfates, and polymers in the purification of water may introduce hazards in some individuals, particularly when coagulants are present in high concentration. Aluminum in treated surface water varies widely, and levels higher than 0.2 mg/L cause discoloration. Water with higher levels may induce encephalopathy [degenerative brain disease] and dementia in patients with kidney disease undergoing dialysis. Aluminum has been linked with Alzheimer’s disease."

Air stripping

Air stripping, also called aeration, removes volatile organic compounds (VOCs) such as trichlorethylene and tetrachloroethylene from water by transferring them to the air. It does not remove non-volatile organic chemicals, of equal or greater concern than VOCs.

Radon is also removed from ground water by air stripping and may pose a risk to treatment plant workers inhaling contaminated air in the proximity of the aeration system. The inhalation of radon is more toxic than ingestion and the risk of radon-related lung cancer may be increased.



Mercury is discharged into rivers and lakes from many industrial sources including pulp and paper mills. Mercury itself and some mercury compounds have low toxicity. However, they can be changed into the highly toxic "methylmercury by microorganisms in the water and in the digestive tracts of animals. . . . Methylmercury penetrates the blood-brain barrier and 10 percent accumulates in the brain, causing irreversible central nervous system damage."

Methylmercury accumulates in fish and fish-eating birds and animals. At each step of the food chain there is a bioaccumulation of mercury. The amount of mercury found in fish may be 3,000 times the original concentration in the contaminated water. Since methylmercury is 1,000 times more soluble in fats than in water, it concentrates in muscle and brain tissue.

An example of a large scale outbreak of methylmercury poisoning occurred in Japan in the 1950s when fishermen and their families at Minamata Bay were stricken with a mysterious neurological disease. The source of the poisoning was the consumption of fish and shellfish contaminated with methylmercury derived from materials discharged into the bay from vinyl chloride and acetaldehyde manufacturing plants. Minamata disease is symbolic of the tragic health risks of industrial pollution of drinking water sources.

Fish contaminated with mercury from industrial wastes and agricultural insecticides has become a source of concern in the Midwest Inland Lakes of the United States. Recent tests of lake water by the EPA were positive for mercury in 90 percent of samples from 380 different sources in Michigan, Illinois, Indiana, and Wisconsin.

At first the symptoms of mercury poisoning are "subtle and diagnosis is difficult. Insomnia, nervousness, tremor, impaired judgment, loss of sexual drive, and depression are symptoms often mistakenly ascribed to psychological causes." Then, "the patient develops a metallic taste, abdominal cramps, diarrhea, and skin rash." Later, symptoms from chronic exposure include "a progressive unsteadiness of gait and slurred speech; delusions and hallucinations; and inflammation of the nerves of the extremities associated with loss of sensation, numbness, and pain in the hands and feet."

Dr. Millichap lists preventive measures that include:

  • Ban disposal of industrial mercurial wastes in waterways.
  • Test inland lakes and other fisheries for mercury and especially methylmercury and issue timely warnings and fishing regulations.
  • Reduce the mercury content of poultry and seafoods, which account for nearly all the mercury intake of Americans.
  • Eat lake fish sparingly and avoid large trout caught in Lake Michigan.
  • Avoid mercury exposure from agricultural chemicals, occupational sources, mercury-containing latex paint, dental amalgams and offices, medicines, thermometers, and household products.


Potential Ground Water Contamination Sources
from Is Our Water Safe to Drink?
J. Gordon Millichap, MD


Lead can be a major drinking water contaminant. In recent EPA tests of water from household taps, "10 public water suppliers in the State of Illinois, including 7 in Chicago suburbs, were included in the list of geographic areas with consumers at risk." Many lead pipes are still in use and the solder in joints between new copper pipes often contain some lead. Water that has been standing in the pipes has the highest lead content so people are advised to run their water first thing in the morning until it becomes cold. Where the drinking water is hard -- has a high mineral content -- deposits in the interior of the pipes can seal off much of the lead. For this reason, the water from the taps of new homes and other buildings where lead-containing solder was used in joining the pipes can present even more danger than the water in older homes where the lead has been covered by deposits from hard water. Obviously, water-softening would counteract these helpful effects.

Chlorinated Hydrocarbons

Chlorinated hydrocarbon insecticides are the most ubiquitous and persistent pesticides in the environment. As an example, traces of DDT have been recovered from dust in the atmosphere that has drifted over thousands of miles and contaminated water formed from melted snow in the Antarctic. . . .

DDT and other chlorinated hydrocarbons are fat soluble. They concentrate in the tissues of animals and are transferred along the food chain, killing fish, birds, and mammals. DDT can bioaccumulate in fish to levels more than 10,000 times the concentration in their aquatic habitat. Biological magnification is the term used for this increased concentration of chemicals as they ascend the food chain from small to larger animals. The levels in human milk may exceed the legal limits permitted in cows’ milk. In fact, an analysis of human milk may be the most accurate measure of the extent of contamination of our environment by pesticide residues and other toxic chemicals.

No Simple Answer

Dr. Millichap asks whether or not our water is safe to drink and replies that there is no simple "yes" or "no" answer, "given the many variables in water sources, environmental factors, and treatment processes." In his book we read of many neurological and gastrointestinal effects. In regard to cancer from each individual chemical in drinking water, the World Health Organization has set an estimated level that would be linked with one additional case of cancer in a population of 100,000 people over their hypothesized lifetimes of seventy years. Each level is set up for just one chemical and we are subjected to many.

Clearly, there is a risk involved by ingesting low levels of organic chemical contaminants every day of our lives and that one additional case of cancer per 100,000 population might be someone close.



*PNB • Publishers, Chicago, Illinois, 1995, 212 pages, hard cover, $21.95.

Article from NOHA NEWS, Vol. XX, No. 3, Summer 1995, pages 1-4.