At least once in your lifetime you’ve heard about anti-fungal painting, or even used it on your own home. Did you know that the same anti-fungal and anti-bacterial properties of such a paint are unbalancing the ecosystem? A scientific study performed in Lausanne, Switzerland, says so.
Sylvain Coutu, from École Polytechnique Fédérale de Lausanne (EPFL), has devised a mathematical model of determining the concentration levels of three biocides usually found in paint: DCMU, Terbutryn and Carbendazim. Tongue-twisting names, I know, but these chemicals actually exist on 60 percent of buildings worldwide.
Heavy rain took those biocides from the walls to the soil and then they infiltrated the underground water streams, reaching the Vauchere river basin in Lausanne, and doing their regular job: killing bacteria, fungi and algae, but in the wrong place: at the bottom of the food chain.
Coutu’s formulas have predicted with an unprecedented accuracy the model by which these substances reach the water streams. Actually, his model proved accurate up to a couple nanograms per liter, which is amazing considering the complexity of the problem. The model simplifies the way water is channeled down the streets, lawns or gardens before reaching the stream.
“A true toxicology report should include peak levels of concentration after rainfall, and we have created the first model that takes them into account over a period of time,” says Coutu.
But the danger that these biocides pose to the entire food chain does not stop here. DCMU, for example, has been developed in the 1950 and is now tagged as a dangerous chemical which can infiltrate in all of the layers of the environment through the food chain.
Although present only in minute quantities (30 nanograms per liter), the biocides discovered in the Vauchere river basin are enough to kill significant amounts of bacteria and plantlife, since they had been designed to kill in low doses from the beginning.
So watch out what you paint you house with!