Chlorine is, quite literally, a lifesaver. It is routinely added to drinking water supplies around the world to keep them safe for human consumption and prevent diseases that in times past killed a large percentage of human populations in some cities. For example, the addition of chlorine to the drinking water of London in the mid-19th century significantly cut down on the number of cases of typhoid, cholera and dysentery, as well as other prevalent waterborne sicknesses of the day. Still, despite its beneficial effects and lifesaving reputation, other chlorine effects on health and the environmental are dangerous to humans.
Chlorine breaks down in water supplies and sewage systems when it reacts with already present organic matter. The main byproducts of this chlorination process are known as trihalomethanes, which include chloroform, among other substances. Trihalomethanes, also known as THMs, have been associated with an increased risk of certain types of cancer, including rectal and bladder cancers. Health officials have not come to an agreement concerning whether the chlorine is a carcinogen.
As anyone who has ever spent time in a chlorinated swimming pool has found out, the chlorine effects are obvious on the hair and skin, as the chemical dries them out. Frequent swimmers sometimes discover the chemical irritates their skin and eyes. One alternative to chlorine effects in swimming pools is ozone, but it does not last as long as chlorine and is considered an expensive and not easily adaptable alternative.
There are also more serious chlorine effects to take into consideration when working with or around chlorine. It can be extremely irritating, even dangerous, to someone with asthma and other lung conditions. Chlorine also can significantly irritate the eyes and skin, and it can cause coughing and throat dryness.
Chlorine gas is poisonous. In the early 19th century, it was even used by armies as chemical warfare. Today it is included in pesticides, paper manufacturing and paper recycling, in plastics and in the making of other chemicals. As a component in laundry bleach, it whitens and removes stains, and it can also clean away mold. In its liquid gas form, it can even cause frostbite if it comes in contact with the skin. A strong warning is usually given when using chlorine because if it is accidentally combined with ammonia, the results could be deadly for anyone who inhales the mixed gases.
Chlorine inhalation should be avoided. Its highly pungent scent is a good warning signal in case of accidental exposure. Also, care should be taken when chlorine is combined with other substances, such as turpentine, because the resulting compound is explosive.