Crystal Nelson
Germany has very good water quality. So good that the German waterworks advertise with nationwide drinking water quality from the tap. In Germany, quality is ensured by a set of rules that is unique in the world and precisely determines the promotion, enrichment, forwarding, and bottling of water.
Nevertheless, studies show that in Germany, too, the contamination of groundwater with substances from, for example, metabolized medicines – i.e. taken by humans and excreted again – and chemical residues from agriculture or heavy industry is increasing. What dangers threaten our health? How effectively do sewage treatment plants filter harmful substances from our drinking water? And what can you do at home to guarantee healthy water quality from the tap? Praxisvita asks you the most important questions about your tap water.
What’s in our tap water?
The list of harmful substances that can be detected in our tap water is very long and keeps getting longer. Recent studies count at least 150 different active ingredients from medicines that can be detected in our water. These include not only hormones – such as the estrogen in the birth control pill – but also quite dangerous substances such as strong opioid residues from metabolized painkillers, non-degradable X-ray contrast media, antibiotics that remain stable for many years, or pesticides that seep into the groundwater from agriculture – so-called pesticide metabolites.
The increasing amounts of radioactive uranium and the extremely toxic substance boron are also of concern, especially because there are currently no binding limit values for these substances in Germany. Other polluting substances found in our tap water – and for which there are no systematic control mechanisms – are, for example, synthetic vitamins and minerals excreted through the body as well as residues of cocaine or other intoxicants.
Where do the substances in our water come from?
Most of the substances that pollute our tap water comes from untreated sewage and are a very characteristic product of modern industrial society. In particular, industrial plants, motor vehicles, and the sewage from cities themselves – for example, due to a damaged sewage system or the legal and illegal disposal of substances – contribute to water pollution. In addition, potentially harmful substances also get into the water through agricultural fertilization and the use of pesticides.
One aspect of water pollution that is gaining more and more attention is the excretion of certain substances by humans. In particular, chemical residues from medicines, but also vitamins and intoxicants, are usually not completely broken down by the body. Whether birth control pills, painkillers, or antihypertensive drugs – they all contain metabolized substances that reach the wastewater directly via the urine or as a degradation product. A recent study also shows that 47 percent of Germans dispose of old medicines down the drain in the sink or the toilet. These migrate via the wastewater either directly into the soil and thus into our tap water or are passed on to our food via agricultural sewage sludge utilization.
Are the substances in the water dangerous?
So far, the controls of the waterworks and various studies have shown that most of the substances detected in tap water are only present in low concentrations due to the high water-substance dilution. The corresponding amounts of most substances are therefore not dangerous for the body. On the other hand, the substances themselves are quite harmful to health – sometimes even deadly. Due to the increasing accumulation of harmful substances in the soil and in the groundwater, the amounts of active substances are constantly increasing. In addition, the detected substances have a major impact on flora and fauna, even in amounts that are not harmful to humans.
gene – are classified as carcinogenic substances, uranium, on the other hand, can damage the kidneys and liver even in very small quantities, and boron is suspected of having a negative impact on male fertility, among other things.
The situation is more complicated when there are drug residues in the water. Although most substances occur in very low concentrations in drinking water, the substances still have an effect. Health risks are officially denied – for example by the Federal Institute for Risk Assessment – but from the scientific side, the long-term consequences of the indirect intake of certain active ingredients, in particular, are not sufficiently researched and therefore not foreseeable. In addition, such active ingredients – if at all – are tested for their individual effects.
In fact, however, it is repeatedly found that individual active ingredients develop interactions when they meet in tap water and in this way can take on so-called oligodynamic properties – i.e. active ingredients reinforce each other and show new, unpredictable effects. Another health disadvantage that can arise from constant contact with active ingredients – such as antibiotics or painkillers – is resistance or habituation effects in the body. This can lead to certain medications not being more or less effective when their use is actually necessary.
Is bottled water also affected?
The simple answer to that is yes. Numerous studies have shown that bottled water is also contaminated with harmful substances. In some cases, the loads are even higher than with tap water. For example, a study by the Goethe University in Frankfurt is Main showed that 60 percent of German bottled water is contaminated with hormones such as estrogen. Pesticide metabolites, on the other hand, were found in around 20 percent of water bottles.
Which substances do sewage treatment plants filter out of the water?
The majority of German wastewater – which is particularly contaminated with hormones and drug residues, for example – is sent to sewage treatment plants and treated there. As a rule, the water is not only filtered but also chlorinated. These cleaning measures are indeed very effective against most bacteria and parasites, but studies show that many drug residues and hormones do not disappear from the water in this way.
The reason is, among other things, that the filters used in sewage treatment plants are too large to be able to filter the smallest particles – such as protein-based hormones – out of the water. There are filter systems that could do this, but they are not used for cost reasons – tap water would become much more expensive this way – and because the amounts of active substances measured in the water are too low.
Is it enough to boil the water?
Boiling water is probably the oldest and most proven method of removing microbial contamination from water. In fact, if you boil the water long enough, most germs that could pollute the water are killed or at least decomposed. However, this only applies to a limited extent in the case of metabolized residues of medication and hormones that are dissolved in the water. Although such substances react very differently to heat, many so-called peptide hormones become inactive at best and do not disappear – many survive the temperature unscathed.
Anyone who boils their water should consider that the many pathogenic bacteria die off or fall apart at a temperature of 70 degrees. Nevertheless, the water must be kept at this temperature for at least eight minutes so that it becomes germ-free.
What do water filters do?
Pure water – in the sense of H₂O – does not exist in nature. This is even very important for human health since minerals bound in water are an important part of human nutrition. Therefore, making water sterile is not healthy. Distilled water can even be harmful to health in higher doses.
Nevertheless, the market for various water filter systems has experienced a significant boom in recent years. A particularly popular filter variant is the so-called table water filter. Such filters are inexpensive to purchase and require no installation. However, these devices are only partially suitable for filtering hazardous substances from tap water. Dirt residues, drugs, and heavy metal residues are not removed by this process, since this filter is primarily intended to be used for decalcifying water. In many devices, the activated carbon filter is treated with silver, so that bacteria can also be killed, but silver particles end up in the water in return.
Another common form is the water filter at the water hose connection. This is a so-called ion exchange process, which filters all tap water. But this filter system is also used primarily to decalcify the water. Studies have shown that the proportion of heavy metals can also be reduced in this way, but other substances – especially inorganic pollutants – are not filtered out of the water. Another disadvantage here is that the ion exchange process does not simply remove foreign substances in the water, but replaces them with others. Most of these filters add minerals to the water in exchange – for example, calcium or magnesium – but the proportion of copper and lead in tap water also increases. In addition, due to the technology used – in which the filter often has to be changed – these devices are susceptible to the contamination that can pollute the water with dangerous pathogens.
Many people basically assume that their tap water – which is often drawn from groundwater – is cleaned by natural rock and soil filtration. Last but not least, this point of view is promoted by the manufacturers of mineral water, who advertise deep cleaning through rock masses. And after all, the groundwater in Germany needs between ten and 40 years until it bubbles up from a source. However, it is not taken into account that pollutants – especially pesticide metabolites from agriculture and drug residues – survive in the soil for decades and that such substances are increasingly accumulating. In addition, such substances also seep into the ground and thus reach the groundwater.
