How dangerous is chlorine in tap water?

How dangerous is chlorine in tap water??

05/06/2013

German drinking water areas suffer from the rainy weather, including Munich. Its public utilities have decided to disinfect drinking water with the help of chlorine. However, the question remains open: Harms chlorine in tap water of human health?

Chlorine in drinking water: how much is allowed?
„It is a precautionary measure“, emphasized Stadtwerke München. They are now fighting with chlorine against supposedly germ-contaminated drinking water from the Mangfalltal, the source of around 80 percent of Munich's drinking water. Due to the high rainfall, the soil there is softened, rain gutters and gullies overcrowded. Because contaminated surface water threatens to flow into the reservoirs, chlorine is now added. An approach that has become rare in this country.

Chlorine should ensure that no faecal germs are present in the drinking water. Its load inspectors check after the so-called „indicator principle“. The pointer E. coli serves as an aid. Although some germs of this species are non-hazardous, E. coli must not occur once in 100 milliliters of water. With chlorine or chlorine dioxide, water utilities reduce the risk of such pollution worldwide. The deusche drinking water regulation allows at least 0.3 milligrams of chlorine per liter of water. In other countries, the values ​​are sometimes significantly higher.

Risks of chlorine in drinking water
But even chlorine is not free of side effects: A permanently high concentration can lead to by-products such as trichloromethane. They should increase the cancer risk slightly, determined several studies. Even if the concentration can not be transferred to German conditions, the consumer's fear remains. „Recent scientific research indicates that exposure to these by-products before birth increases the risk of birth defects“, cites Dr. Hans-Joachim Paulski is the result of a study by the University of Birmingham.

Dr. Ingrid Chorus from the Federal Environment Agency states: "Depending on the quality of the raw water, after-chlorination may produce by-products suspected of being carcinogenic, but if you drink this water for a short time, it is highly unlikely that these effects will occur It has been clearly proven that germs in drinking water transmit dangerous diseases, so chlorinating drinking water where the occurrence of pathogens can not be reliably excluded is the lesser evil.“

Drinking water quality Germany: a pioneer in international comparison
The German drinking water is of consistently high quality. It fulfills 99 percent of the legal requirements, determined a study by the Federal Ministry of Health in 2012. The required limits were therefore exceeded only in a few exceptional cases, including by pesticides or coliform bacteria. Drinking water can be taken in Germany accordingly without concern. „The qualitative features are still getting top marks“, said the President of the German Federal Environment Agency Jochen Flasbarth.

What applies to German utilities, however, can not be transferred abroad. Depending on the region, there are sometimes high levels of industrial pollutants in tap water, for example in the Caribbean islands of Martinique and Guadeloupe. The World Health Organization estimates that unclean water is responsible for 80 percent of travel illnesses. Travel medicine doctor Helmut Jäger advises in case of doubt whether the water quality for boiling. As a result, harmful bacteria are killed, evaporated by water supplier added chlorine. (Lb)

Picture: Lupo