Our drinking water is increasingly a topic for discussion. Although we like talking about “the most monitored foodstuff” – experts warn of new risks lurking in drinking water.
Even the applicable limit values (‘legally tolerated volumes of contaminants’) need to be viewed critically.
High nitrate values in particular, caused by the fertiliser methods of conventional agriculture, should concern us all. The limit value for nitrate, a nitrogen compound which the body converts to carcinogenic nitrous amines is 50 mg per litre in Germany and 40 mg per litre in Switzerland today.
In Austria, the limit value was revised upwards from 25 to 50 mg per litre in 1995. For the youngest of us, such contaminant values are already much too high. The World Health Organisation (WHO) therefore recommends that water intended for babies does not contain more than 10 milligrams of nitrate per litre.
Pharmaceutical products are regularly taken by the majority of the population these days. Contraceptive pills and antibiotics ahead of everything else. After administration of medication and release of the actual active agent, this is absorbed by the body via different routes (e.g. lung or intestine). Often only a small amount of the active agent is present at the action site, while the majority is stored in other areas of the body. Thus, the majority of active agent volumes, critics refer to over 90%, is excreted unmetabolised and thus into the groundwater.
“Der Feinschmecker” [German gourmet magazine] allowed magazine employees to fill tap water from public buildings and private residences in laboratory bottles which were then sent to Tübingen for chemical analysis at the Institute of Prof. Dr. Walter Jäger. Result: surprisingly high x-ray contrasting agent and anti-epilepsy medication values were found in the tap water from the Berlin Reichstag and residences in Essen and Dortmund.
N24 [German TV channel] reports, “The hygiene institute at the Medical Faculty of the Ruhr University- Bochum took samples from taps on behalf of the WDR. In Essen, there was residue of four x-ray contrast agents and in Bochum of two x-ray contrast agents. Furthermore, the scientists in Bochum apparently discovered residue from epileptic medication. Although the health of the population is not endangered due to the small volumes, it is obvious that all of the substances do not belong to drinking water, Institute Director Michael Wilhelm evaluated.“ (www.n24.de, 26.05.2008)
From a publication of the WDR [German tv channel]: “After the administration of medicinal products, some of the active agents are excreted from the body again a little later and are deposited in the wastewater with the urine. Some simply carelessly discard medicinal products into the toilet. However, many pharmaceutical substances are not filtered out in the sewage plants, but enter the surface waters again diluted and even into the drinking water under some circumstances. Technically, it has long been possible to filter undesirable substances from the water. However, many municipal utilities are not prepared to invest in new filter systems. In a Germany-wide investigation, higher concentrations of psychopharmaceuticals were discovered in tap water, for example. The result of a current study by the State Environmental Agency in Recklinghausen is that the water in North Rhine-Westphalia is especially contaminated – however, there are not yet any limit values for medication residues in drinking water.“ (www.wdr.de, 14.12.2007)
The consumer is compelled to a critical, self-determined stance vis-à-vis the ‘most controlled foodstuff’ due to potential contamination of the drinking water which appears to still be hardly avoidable despite the many efforts of public water suppliers“.
These are predominantly the heavy metals lead, copper, nickel, zinc, cadmium, manganese, thallium and uranium, the radionuclides Radium 226, 228, asbestos fibres, bacterial contamination, medication residues of contraceptive pills and antibiotics and chemical pesticides (pesticides, herbicides) from agriculture which contaminate the tap water. Public water supply companies are obliged to supply the consumer a quality of water to the domestic water connection in accordance with the Drinking Water Regulation (TVO) which does not exceed the limit values of the permitted contaminant volumes. For this purpose, the water works apply different physical and chemical cleansing methods, for example, filtration, chlorination, ozone treatment or UV radiation. From domestic water connection to the tap, the responsibility for water quality lies with the householder, regardless of whether single-family or multi-storey buildings are involved.
Pay attention to aged piping systems (more than 30 years old) made of lead. The limit value of 25 micrograms per litre does not generally need to be complied with if the tap water is flowing through old lead pipes. Stagnant waters from such installations can show up to 330 micrograms per litre. Excessive contamination of the drinking water with copper is considered a possible cause of early childhood liver damage. Copper can get into the drinking water as a corrosive product in considerable volumes, especially when it is standing in copper domestic installations for a long time. The limit value is two milligrams per litre. Excessive contamination of drinking water with lead and copper cannot occur if the clauses of the drinking water regulation are complied with and the domestic installations are executed properly.
The heavy metal uranium is classified as especially dangerous, less due to its weak radioactivity than due to its toxic qualities. The German expert for uranium in drinking water, Professor Ewald Schnug from Brunswick University refers to the fact that especially infants and small children are affected by the risk, as uranium attacks their still little-developed kidneys, lungs, livers and bone marrow.
Prof. Ewald Schnug