Results from the Swedish Screening 2005. Subreport 2. Biocides

.As an assignment from the Swedish Environmental Protection Agency, IVL has performed a 'Screening Study' of the following biocides: bronopol, 4-Chloro-3-cresol, 2-Mercaptobenzothiazole, N-didecyldimethylammoniumchloride (DDMAC), Propiconazole, Resorcinol, 2-(Tiocyanomethylthio)benzothiazole, triclosan, Methyl-, Ethyl-, Propyl-, Butyl- and Benzylparabene. The overall objectives of the screening were to determine concentrations in a variety of media in the Swedish environment, to highlight important transport pathways, and to assess the possibility of current emissions in Sweden. In total, 132 samples of air, precipitation, effluent water, surface water, sludge, sediment, fish, foodstuff and human urine have been analyzed. The background sites were generally non-contaminated, only 2 out of 17 background samples contained detectable amounts of biocides, and in these samples only two substances were found;namely triclosan and 2-mercaptobenzothiazole. Due to regular presence in samples of wastewater effluents, sludge and urban sediments, on-going emissions are likely to occur for 2-mercaptobenzothiazole, triclosan, DDMAC and parabenes. Observed concentrations were, however, below risk levels. The atmosphere was identified as a possible transport matrix for triclosan, 2-mercaptobenzothiazole and parabenes. Bronopol, resorcinol and 2-(tiocyanomethyltio)-benzothiazole were not detected in any of the samples analyzed, and were considered to pose no environmental risks. Propiconazole may be of local concern but at present it is unlikely to cause any problems on a national level.