Xenobiotic Compounds in the Water Cycle
Chair: Prof. Dr. Fritz Frimmel, University of Karlsruhe
on March 2nd, 2007
Daily Life and its Legacy
Using cosmetics is, in today's industrial nations, just as natural as eating and drinking. The low prices of innumerable No-Name products don't even presuppose a particularly high standard of living. As a result, they are used in large quantities. These so-called "Personal Care Products" (PCP), however, contain a number of substances which enter into the water cycle by way of the sewage.
There, the residues of medicines, resp., of the medicines' active ingredients are also found, which, due to the demographic trend and to the high standard of health care, are used intensively. Another group of "agents" is contained in dyes, foods, and many other products for daily use: synthetic nanoparticles (Engineered Nanoparticles, ENP), which are mostly only a few nanometers (billionths of a meter) in size.
Sewage Treatment Plants Insufficient?
Like cosmetics, active medicinal agents and nanoparticles are not of natural origin, but are produced by human beings. All three of these substance classes are widespread and extensively used – and they come, each of them over its own path, by way of the municipal sewage plants, into the water cycle. In the case of medicinal agents and cosmetics, it is well-known that a number of compounds are only insufficiently eliminated in municipal sewage plants. The original substances flow unchanged, together with possible metabolic products out of the sewage treatment plants and into the receiving waters.
The reactions of engineered nanoparticles in municipal sewage treatment are, to a great extent, unknown; because of their physical properties, however, we would have to assume that their elimination is also incomplete, and that they are transported into the receiving waters to a high degree.
Possible Impacts on the Environment Unknown
Whether and to which extent Personal Care Products, active medicinal ingredients, and engineered nanoparticles have detrimental effects on the environment is still – largely – unknown. Only medicinal agents have to be tested in this respect before they are approved. In product development, ecotoxicological effects play to the present merely a minor role. In order to be able to make a sensible risk evaluation, new testing procedures have to be developed and tested.
Improved risk assessment, as well as improved hazard-benefit estimation could, finally, provide a basis for a better, environmentally compatible product design and help to develop preventive strategies for sustainable use of these everyday products.