High concentrations of chlorine can be dangerous, especially for young children: prolonged exposure to chlorine can lead to asthma or hay fever.

Water treatment with chlorine
Microorganisms can be found in rivers, lakes and groundwater. Not all of them are harmful to health. But some make us sick. These pathogens can be transmitted via drinking water and cause diseases.

Various disinfection methods are used to prevent this. Together with other water treatment processes such as coagulation, sedimentation and filtration, the water is purified in such a way that it can be drunk and used for cooking without any problems.

Chlorination is an option that was used more than a century ago and is still used today. And is still used today. This is a chemical process that uses various types of chlorine or substances containing chlorine to oxidize and disinfect drinking water.

Possible health effects
A high concentration of chlorine can be dangerous and have health consequences:
- Food allergies
- (More severe) asthma or an increase in respiratory diseases
- Rectal and bladder cancer
- Various congenital anomalies
- Bad smell and taste

If you regularly drink tap water that has a high concentration of chlorine, you should keep an eye on your health.

Most of these consequences are due to trihalomethanes (THM), which includes chloroform. THMs are formed when chlorine reacts with organic particles in the water. Long-term consumption can lead to the following health consequences, among others:

food allergies
Dichlorophenols are chemical compounds that can be found in chlorine. Studies have shown that people who have high levels of this substance in their bodies are more likely to have allergic reactions to various foods.

Asthma Symptoms
Chlorine can make asthma symptoms worse and lead to more breathing problems. These include chest pain, trouble sleeping, and shortness of breath. Worsening of these symptoms may occur when swimming or showering in chlorinated water. When showering, chlorine can be inhaled via the chlorine vapor or absorbed directly through the skin.

rectal and bladder cancer
The THM byproducts of chlorination can increase the risk of developing rectal and bladder cancer. However, studies have found only a weak connection between increased chlorine concentration and increased risk of cancer.

Various congenital anomalies
Pregnant women are particularly at risk. Children may be born with abnormalities such as ventricular septal defect, poor brain development, or a cleft palate. A ventricular septal defect is a defect in the dividing wall (ventricular septum) between the two chambers of the heart. The defect can be located in different parts of the septum, most commonly below the aortic valve (subaortic), less often in deeper areas (so-called muscular defects).

Bad smell and taste
While not necessarily harmful to your health, water that has too much chlorine can smell and taste bad. Then you shouldn't drink it anymore. But: You should not resort to unhealthy drinks instead of water.