Another chemical poison of the PFAS group detected in drinking water
In the Bavarian chemical triangle in the district of Altötting, which has been struggling with heightened PFOA levels in drinking water for many years, another environmental toxin of the PFAS class, GenX, has been found at several measuring points, although in each case below the limit value. The chemical, which is used as a basic material for impregnations and coatings, is very environmentally stable and, like PFOA, is also suspected of being carcinogenic. PFOA has been banned throughout the EU since 2020.
Along with food, drinking water is considered the crucial source through which toxic PFASs can enter the human body. Actually, GenX, which has been produced since 2009, should replace the banned PFOA in industry. Both chemicals belong to the group of per- and polyfluorinated alkyl substances (PFAS), which comprises about 5,000 substances. The European Chemicals Agency classifies GenX, or HFPO-DA as it is correctly called, as a “substance of very high concern”, even though it is supposed to be somewhat less harmful to health than PFOA.
With conventional activated carbon filters such as the Seccua Biofilter, the content of GenX/ HFPO-DA in drinking water can also be effectively reduced. Depending on the PFAS concentration in the water, the filtering effect of the activated carbon can decrease over time, so it must be replaced at certain intervals.
PFAS limits in the new German Drinking Water Ordinance 2023
A new, completely revised version of the German Drinking Water Ordinance will come into force at the beginning of 2023. In the new Drinking Water Ordinance, stricter limit values for four PFASs will also be defined for the first time. These are to be set at 20 nanogrammes per litre of drinking water. Per- and polyfluorinated alkyl substances (PFAS) have already been included in the EU Drinking Water Directive at the beginning of 2021. Since they are hardly degradable in the environment, they can accumulate there and also in the human body. Because they are harmful to health, the EU has now banned the use of the four individual compounds PFOA, PFOS, PFHxS and PFNA, which have been most frequently detected in human blood.
A comprehensive meta-study on PFAS in German drinking waters with over 1,200 samples has shown that they do occur throughout Germany. Drinking waters obtained from groundwater are just as affected as those from resources influenced by surface water.
However, depending on the analysis parameters and assumed aggregate limits of PFOA, PFOS, PFNA and PFHxS, between 5 % (moderate impact on water supplies) and 29 % (almost one third of all samples, i.e. significant impact) of water supplies are affected. In total, only 5 % of the samples have PFAS levels above half the planned limit of 20 nanograms per litre.
The toxic effect of PFASs due to a short-term high intake is thus rather low. But since PFASs are bioaccumulative, i.e. they can accumulate in the body over time, little is known about long-term effects. In the USA, increased cases of cancer have occurred in the vicinity of PFAS-processing plants.
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