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What are the Dangers of Chlorinated Water?

Harriette Halepis
Harriette Halepis

Many sources of tap water within North America are treated with chlorine. Chlorine is added to water in order to eliminate various microorganisms that may cause illnesses if left untreated. However, chlorinated water may also lead to other illnesses, including trihalomethane (THM) contamination. Presently, a large debate surrounding the safety of chlorinated water is ensuing.

Trihalomethane is a type of disinfection by-product that is produced when chlorine is added to a drinking water source. Amongst other things, THM contains chloroform. The amount of THMs that can be found within a water supply vary according to seasonal changes. While a large amount of chlorine is added to water during the summer months, this amount is reduced during the wintertime. The reason for this is that natural organic matter increases when temperatures are warmer.

A water tower.
A water tower.

Since chlorine is added to water in order to reduce any kind of waste matter, chlorine levels are increased during warmer months. In addition, wells and lakes do not contain as much chlorine as rivers and other types of surface water do. Surface water tends to have a vast amount of organic waste, which is why chlorine levels are higher within this kind of water source.

Some people choose to drink bottled water out of fear of the dangers of chlorinated water.
Some people choose to drink bottled water out of fear of the dangers of chlorinated water.

Some studies have shown that a high amount of THM may increase a person's risk of cancer. These studies have revealed that people who rely solely upon chlorinated water as a main drinking source for at least 35 years may have a greater chance of developing colon or bladder cancer. In addition, THMs may also contribute to miscarriages. A recent study has shown that pregnant women who drink chlorinated water tend to have more miscarriages than those women who do not drink chlorinated water.

Tap water often has been treated with chlorine.
Tap water often has been treated with chlorine.

While these health risks are of concern to many people, the benefits of chlorine upon drinking water are enormous. In fact, most studies show that the benefits associated with chlorinated water greatly outweigh any possible THM risk. Chlorinated water prevents diseases such as cholera and typhoid fever from forming. Without chlorine, these diseases would quickly spread from household to household.

Most governments have concluded that the benefits of using chlorinated water outweigh the risks.
Most governments have concluded that the benefits of using chlorinated water outweigh the risks.

Even though some risk may be associated with chlorinated water, most governments that rely upon chlorine to treat drinking water claim that a minimal amount of THM is safe for human consumption. People who are concerned about the effects of THM may be able to reduce the amount of THM consumed by using an activated carbon filter. Water filters that contain carbon have the ability to effectively remove chlorine by-products and chlorine. While these filters will help to reduce THM levels, it is important that the instructions included on a filter package be acknowledged.

Discussion Comments

anon88691

which is the best for long term: GI pipe or cpvc?

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    • A water tower.
      By: chandelle
      A water tower.
    • Some people choose to drink bottled water out of fear of the dangers of chlorinated water.
      By: monstersparrow
      Some people choose to drink bottled water out of fear of the dangers of chlorinated water.
    • Tap water often has been treated with chlorine.
      By: AA+W
      Tap water often has been treated with chlorine.
    • Most governments have concluded that the benefits of using chlorinated water outweigh the risks.
      By: luchshen
      Most governments have concluded that the benefits of using chlorinated water outweigh the risks.
    • Chlorine is used to eliminate micro-organisms in water that can cause illness, but may cause some problems on its own.
      By: Jiri Hera
      Chlorine is used to eliminate micro-organisms in water that can cause illness, but may cause some problems on its own.