Model shows how facade pollutants (eg anti-fungal house paints) enter the environment

Concern raised at biocides reaching watercourses at harmful levels.

"The biocides that reached a river basin in Switzerland did so in extremely small concentrations—30 nanograms per liter, or 30 parts per trillion, of the chemical DCMU were present after heavy rains. DCMU is a common herbicide and algicide developed in the 1950s in Germany and the threshold concentration after which this substance is considered a threat for the environment is 20 nanograms per liter. DCMU is considered harmful and can potentially kill algae and other plantlife by inhibiting photosynthesis and thus depriving the organisms of energy. Biocides in general do not degrade easily, thus increasing their risk of moving up the food chain and making their way, in higher and higher concentrations, throughout the environment."