Disinfected or dangerous?
What you don’t know about chlorinated drinking water may compromise your health.

Chlorine gas was used as an agent in chemical warfare during the First World War. This same noxious gas is inhaled daily as a result of common activities such as bathing, showering, boiling water, washing dishes and doing laundry.

Once considered the miraculous eliminator of disease epidemics, chlorine may ultimately go down in history as one of modern humanity’s worst assaults on the earth, and even on our own species! Chlorine is a greenish-yellow gas produced when electricity passes through a solution of salt and water. This virulent chemical is used as a bleaching agent in the paper, pulp, and textile industries, as well as a disinfectant for drinking water.

The continuous chlorination of drinking water first began early in the 20th century, resulting in virtual elimination of waterborne diseases such as typhoid, cholera, dysentery, and hepatitis A. Chlorine does more than just kill microorganisms, however. It reacts with organic matter naturally present in water, forming a group of chemicals known as disinfection byproducts. Trihalomethanes (THMs), which include chloroform, are the most common of these subgroups.

Scant attention has been paid to skin absorption, or even inhalation, of volatile organic compounds such as chlorine. “Skin absorption of contaminants has been underestimated, and ingestion may not constitute the sole or even primary route of exposure,” says Dr. Halina Brown of the A report by Greenpeace, “Body of Evidence: The Effects of Chlorine on Human Health,” is the first to assess all current evidence on the effects of chlorinated compounds, commonly known as organochlorines, on human health. The report () indicates organochlorines are disrupters of critical hormone levels in the body, a trend that can be measured in people all around the world. Infertility, birth defects, and altered levels of sex hormones are part of this trend, posing a grave threat to the ability of humans to reproduce. Children are also most susceptible to damage from exposure to toxic chemicals such as chlorine.

The Greenpeace report explains that as organochlorines break down, they typically yield a second generation of organochlorines, some of which are more toxic and persistent than the original substances. Once they become airborne, they can become global pollutants.

Chlorine gas was used as an agent in chemical warfare during the First World War. This powerful irritant can indeed be fatal upon inhalation. Consider that this same noxious gas is inhaled daily in most households as a result of common activities such as bathing, showering, boiling water, washing dishes, and doing laundry.

Methods of exposure
Studies from the University of Pittsburgh Graduate School of Public Health revealed less chemical exposure from drinking chlorinated water than using it to wash clothes or shower. Other experts suspect showering with chlorinated water as the primary cause of elevated levels of chloroform in the home.

Like chlorine, chloroform and other disinfection byproducts such as trichloroethylene (TCE) and benzene, are readily absorbed through the lungs into the bloodstream. According to Dr. Julian Andelman’s research, hot showers (42 C) can release about 50 per cent of the dissolved chloroform and 80 per cent of the dissolved TCE into the air.

An article in the in 2000 reports, “Researchers recorded increases in chloroform concentration in bathers’ lungs of about 2.7 parts per billion after a 10-minute shower. Worse, warm water causes the skin to act like a sponge; and so, one will absorb and inhale more chlorine in a 10-minute shower than by drinking eight glasses of the same water.”

Contaminants can also adversely affect the skin itself, destroying its natural ecology. Chlorine chemically bonds with organic materials such as skin, scalp and hair, causing them to dry out and worsening dandruff. Hair may become brittle, rough, and lose colour and shine. Chlorine may also irritate the skin, eyes, sinuses, throat, lungs, and weaken immunity.

Chlorine in swimming pools isn’t much safer as it reacts with organic matter such as sweat, urine, blood, feces, mucus, and skin cells to form more chloramines. According to the above-mentioned report, “Chloroform risk can be 70 to 240 times higher in air over indoor pools than over outdoor pools. Canadian researchers found that after an hour of swimming in a chlorinated pool, chloroform concentrations in the swimmer’s blood ranged from 100 to 1,093 parts per billion.” The article suggests we avoid any pool that smells strongly of chlorine.

James Potts, PhD, conducted a 1994 study at the University of British Columbia that revealed an extraordinarily high rate of asthma and other respiratory ailments among competitive swimmers. His findings suggest the likely cause is exposure to chemicals in pool water.

Reducing chlorine exposure

Shower filters: the Kinetic Degradation Fluxion (KDF) method of filtration contains a special high-purity copper/zinc alloy that removes chlorine, heavy metals, bacteria, and hydrogen sulphide from the water. KDF, an oxidation-reduction process, works by exchanging electrons with contaminants and converting them into harmless components, or binding them to the KDF media. This type of shower filter, available in health food stores, is effective even at higher operating temperatures and flow rates, and usually retails around $45 and up.

Bath filter balls, containing an extra-fine KDF filament, float in the tub and are reputed to remove 90 per cent or more of chlorine from water. If you are unable to filter your shower or bath water, try at least to use a cooler water temperature, as this will release lower levels of chlorine vapour. Where possible, improve ventilation in bathrooms, kitchens, and laundry rooms, as these areas usually harbour higher chloroform levels.

Another lesser-known route of toxin exposure is through bleached personal care and household paper products. Buy unbleached toilet paper, paper towels, diapers, and, for women, unbleached organic sanitary napkins and tampons (see the “Reach for Unbleached” campaign at ).

For drinking water, numerous types of home-based treatment systems are available. The resources below should get you started. Resources:

Health Canada’s Water Quality Program: Water Treatment Equipment: A Buyer’s Guide: A Buying Guide for Water Filters: Did you know?

Exposure to chlorinated water has been linked to:

  • Altering and destroying essential fatty acids (the building blocks of human brains and central nervous systems).
  • Creating free radicals that generate dangerous toxins in the body.
  • Atherosclerosis (hardening of the arteries), high blood pressure, heart disease, anemia, allergic reaction and cancers of the colon, rectum, pancreas, liver and bladder.
  • Added risk for individuals undergoing dialysis treatment.
  • Miscarriages, low birth weight, and birth defects such as spina bifida.

Chlorinated drinking water: Health or hazard?

Josef Tyls III, MSc, PhD
Bladder cancer has been linked to chlorinated drinking water in epidemiological studies.

How harmful is it to consume chlorine and chlorine disinfection byproducts in our water? Proponents of chlorine claim there is no danger. But not all the information has been
disclosed to the general public.

Water and our health and wellness

Clean water is absolutely essential for all proper body functions, including skin and organ integrity, immune system balance, cellular respiration and repair, waste elimination, and longevity.

The primary purpose of clean water within the body is to transport nutrients to the cells and then transport waste byproducts to the eliminatory system. It is absolutely essential in maintaining the critical balance needed to support life. Yet this system, with its multiplicity of interrelated dependencies, can be grossly affected by minute traces of chemical toxins like chlorine.

Hazardous byproducts of chlorination

Chlorine is used to disinfect municipal water supplies and swimming pools from harmful bacteria. But chlorine is also a highly toxic element, which has an ability to oxidize all proteins, effectively rendering them useless. All living organisms are made up of proteins. Hence, any living organism that comes in contact with even trace amounts of chlorine is affected and, if exposed to sufficient quantities of chlorine, killed.

The major health issue regarding the chlorination of municipal water is that it exposes us to a variety of toxic chemicals called trihalomethanes (THMs), which are byproducts of chlorination. Studies have linked THMs to miscarriage and fetal malformations, and they may be also associated with an increased risk of stillbirths. One of the most common of the THMs, chloroform, is classed as a potential cancer-causing agent. In public pools it has been measured at more than twenty times the level found in tap water. Little data exists regarding dermal and inhalation exposure routes to the chloroform body-burden from domestic and recreational use of chlorinated water.

And not all harmful bacteria are effectively disinfected by chlorine. The bacteria Cryptosporidium parvum, excreted in the feces of infected humans, cattle, and other mammals, is highly resistant to chlorine at the levels normally found in swimming pools and drinking water. Giardia lamblia is also more resistant to disinfection by chlorine, but can be effectively filtered.

How safe is showering?

Volatile chemicals like THMs can evaporate from water in a shower or bath. Conservative calculations indicate that inhalation exposures can be as significant as exposure from drinking the water; that is, one can be exposed to the same amount of THMs by inhaling during a shower as by drinking two litres of water a day. People who shower frequently could be exposed through ingestion, inhalation, and/or dermal absorption.

Some studies found that the dangers from inhaling chlorine can even exceed those derived from drinking chlorinated water. The amount of chloroform, the most common trihalomethane in chlorinated water, inhaled or absorbed through the skin during a typical shower may be six times higher than that absorbed from chlorinated drinking water.

The cancer connection

Epidemiological studies funded by Health Canada concluded that 14 to 16 percent of bladder cancers in Ontario may be attributable to drinking water containing relatively high levels of chlorination byproducts. According to the results of a 1992 Norwegian study published in the International Journal of Epidemiology, the consumption of chlorinated drinking water has been associated with a 20- to 40-percent increase in the incidence of colon and rectal cancer.

A study done by the Medical College of Wisconsin and Harvard University found that the consumption of chlorinated drinking water accounts for nearly 15 percent of all rectal cancers and nine percent of all bladder cancers in North America. The study also concluded that drinking chlorinated water over long periods of time increases the chances of contracting rectal cancer by 38 percent and contracting bladder cancer by 21 percent. In addition, among those who drank chlorinated water, the researchers found a higher incidence of cancer of the esophagus, rectum, breast, and
larynx, as well as Hodgkin’s disease.

Josef Tyls III, MSc, PhD, is an industrial engineer who specializes in H2O processing and related technologies.