EN
The influence of roofing material on concentrations of pollutants in roof runoff waters and changes of pollution concentration in time were investigated. In field studies four roofing material types were taken into consideration: ceramic tile, bituminous membrane, asbestos tile, and zinc sheeting. Samples were collected from November 2007 to March 2008. Anions, cations, metals, PAHs, pesticides, and PCBs were determined. The existence of the first flush phenomenon for most pollutants was confirmed, with concentrations up to two orders of magnitude higher in first flush compared to steady state conditions. Time trends of pollutant concentration changes were observed. Additionally, analysis of a series of samples collected from melting snow accumulated on the roof showed an increase of organic pollutant concentrations during thaw.