Chlorine

A high chlorine concentration can be dangerous, especially for small children: If chlorine is ingested over a longer period of time, there is a risk of asthma or hay fever.

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

To prevent this from happening, various disinfection processes are used. Together with other water treatment processes such as coagulation, sedimentation and filtration, the water is purified so 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. It is a chemical method that uses different types of chlorine or chlorine-containing substances to oxidise and disinfect drinking water.

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

If you regularly drink tap water that contains a high concentration of chlorine, you should keep your health in mind.

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

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

Asthma symptoms
Chlorine can make the symptoms of asthma worse and lead to more frequent breathing problems. These include chest pain, sleep disturbances and shortness of breath. Worsening of these symptoms can occur when swimming or showering in chlorinated water. When showering, chlorine can be inhaled from the chlorine vapour or absorbed directly from the skin.

Rectal and bladder cancer
The THM by-products produced during chlorination can increase the risk of developing rectal and bladder cancer. However, studies have found only a small association between increased chlorine concentration and increased cancer risk.

Various congenital anomalies
Pregnant issues are particularly at risk. Children can be born with anomalies such as ventricular septal defect, poor brain development or a cleft palate. In a ventricular septal defect, there is a defect in the septum (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), and less commonly in deeper parts (so-called muscular defects).

Bad smell and taste
Although it is not necessarily harmful to health, water that contains too much chlorine can smell and taste bad. You should then stop drinking it. But: You should not resort to unhealthy drinks instead of water.

Sources:
https://sensorex.com/2021/01/18/the-effects-of-chlorine-in-water/
https://longsecowater.com/blog/chlorine-in-drinking-water-what-are-the-effects
https://www.safewater.org/fact-sheets-1/2017/1/23/what-is-chlorination