The presence of perfluoroalkyl acids in drinking water in the Netherlands indicates that current water purification methods are inadequate in preventing exposure to these possibly harmful substances. This is the finding of PhD researcher Christian Eschauzier, who will be defending his dissertation at the University of Amsterdam on Friday, 29 November.
Perfluoroalkyl acids (PFAAs) are substances commonly used in industrial and consumer goods because of their water, fat and dirt repellent properties, and their microbial and chemical stability. They are used in the manufacture of waterproof jackets, fire extinguishing materials and non-stick layers in pans. The existing purification methods for drinking water - such as dune filtration and ozone treatment - have little or no effect on the removal of various PFAAs. As a result, some of these substances found in freshwater sources such as the River Rhine are present in the drinking water distilled from the river, and even in coca cola from post-mix dispensers in the catering sector and in machine coffee.
Eschauzier researched the extent to which PFAAs are present in drinking water (prepared from surface or ground water) and examined the origin of PFAAs in these water sources. He has found that various kinds of PFAAs cannot be removed entirely, or can only be partially removed. This means that our drinking water, as well as our regular daily food intake, can contribute substantially to our total exposure to these substances. Exposure to such substances results in a widespread occurrence of PFAAs in human blood.
Eschauzier also focused on finding more efficient materials for removing PFAAs from water. He discovered that ion exchangers are suitable for removing substances known as short-chain perfluoroalkanes, while long-chain alkanes are best removed using activated carbon.
Although the concentrations found in drinking water are within the permissible limits, there is still plenty of debate about the toxicology of PFAAs. The presence of PFAAs in drinking water is not routinely monitored. Eschauzier recommends that these substances be included in routine monitoring programmes used by drinking water producers to monitor water quality.
C. Eschauzier, Perfluoroalkyl Acids in Drinking Water: Sources, Fate and
Supervisor: Prof. W. P. de Voogt
Time: Friday, 29 November at 12:00.
Venue: Agnietenkapel, Oudezijds Voorburgwal 231, Amsterdam