Status: 22/09/2023, 04:56 a.m.
By: Teresa Toth
Many refrain from lugging heavy bottles and prefer to quench their thirst with tap water. What makes sense in principle can also be harmful to health.
Frankfurt – Tap water is the ideal thirst quencher. It is not only more climate- and environmentally friendly than packaged water from the supermarket, but is also easy on the wallet and is usually always available – because if you don't drink enough, you can damage your health. In some cases, however, the water from the tap itself can also be harmful to health – for example, if it is contaminated with toxic substances.
|Substances that can get into tap water||Possible consequences|
|Lead||Deposition in the body, damage to the nervous system|
|Copper||Gastrointestinal discomfort in infants|
|Nickel||Allergic reactions to nickel allergy|
|Legionella||Flu-like symptoms up to pneumonia|
Risk of harmful substances in the water: High lead content in new fittings
As Stiftung Warentest explains, outdated fittings can be to blame for such contamination. The greatest danger is when lead has been processed. This is the case with brass fittings. These consist of copper and zinc. In order to better combine the two substances, lead is added. "Especially with new fittings, lead can pass into drinking water at the beginning," explains Stiftung Warentest.
If the body absorbs lead, it cannot break down the substance – it is deposited in the bones, muscles and brain. Even the smallest amounts of lead can subsequently damage the nervous system, as the Federal Environment Agency writes on its website. The unborn child, infants and toddlers are particularly at risk. In addition, lead makes "stupid, especially if the brain is still developing," writes Stiftung Warentest.
Contaminated tap water: Consumers can test for themselves whether lead pipes have been installed
In addition to outdated fittings, lead can also get into the tap water through lead pipes installed in the house. It is not known how many households still have lead pipes – since this year there has been an official ban. It provides for the replacement of the pipes by January 12, 2026. If you are unsure whether lead pipes are installed in your home, there are some tests you can perform:
- Check visible lines: Lead pipes are significantly softer than other pipes. They are easily carved with a knife and are silver-gray.
- Ask the landlord: As a rule, you can tell when the pipes were installed and whether they may be lead pipes.
- Laboratory measurement: Measurements provide information on whether the water is contaminated with substances that are harmful to health.
- Sources: Stiftung Warentest, Federal Environment Agency
A basic rule is: Always let some water drain before pouring it into a glass or using it for cooking. This is especially true if the water has been standing for a while. Water filters are of little use. Instead of purifying the water, they often carry the risk of harmful germs in the water.
Major milk recall in Germany: Several popular brands affected – infection possible
Numerous users want to get rid of them: New WhatsApp function rolled out in 150 countries
Driving licence changes for seniors: EU plans strict regulations
Cardiovascular diseases: how high the degree of disability can be
Traffic light coalition causes price hammer – "All consumers will have to pay more from December"
Fancy a voyage of discovery?
In addition to lead, there are several other substances that can contaminate tap water
In addition to lead, there are a number of other substances that get into tap water unnoticed or are contained in too high a concentration. These include copper, nickel and legionella. According to Stiftung Warentest, the limit value for copper is set quite high, but tap water with a high copper content can lead to gastrointestinal complaints in sensitive infants. Nickel, on the other hand, only becomes a danger if there is an intolerance. Those affected should also let the water flow out of the tap for a moment until they use it.
An important rule is: let the water run for a short time before drinking it. © Francis Joseph Dean/imago
Contamination with Legionella is much more problematic. These are bacteria that multiply in warm water. According to the Federal Center for Health Education (BZgA), they can cause flu-like symptoms or even pneumonia in humans. In order to avoid contamination, Stiftung Warentest recommends that showers should not be placed in dirty dishwater or in buckets of cleaning water, for example. According to the BZgA, water pipes should also be used regularly to avoid a water standstill.
Water from the tap: In case of doubt, an analysis can provide information
A recent study from Spain also showed a connection between a high nitrate concentration in tap water and cancer: The researchers found that the higher the nitrate intake, the higher the probability of developing prostate cancer.
If you are unsure whether your tap water is drinkable, an analysis makes the most sense. As Stiftung Warentest explains, some water providers even offer free analyses when pregnant women or babies are in the household. (tt)