Organic pollutants in precipitation: monitoring of pesticides and polycyclic aromatic hydrocarbons in the region of Trier (Germany)

Organic pollutants are nowadays part of our environment and they can be found in every compartment, though in different levels of concentration. Studies which are related to the content of these substances in precipitation deal with very low concentration levels which, nevertheless, cannot be ignored. The city of Trier, with nearly 100,000 inhabitants, is located at the river Moselle, in south–west Germany, and is one of the main centres of the vinicultural area of the Moselle-Saar-Ruwer, where pesticides, among them many fungicides, are widely used. In this study, rain samples were weekly collected, from July 1999 till December 2000, in nine different sites, and two classes of compounds were investigated: PAHs and pesticides, with a particular attention on selected fungicides. Sampling sites were selected in order to evaluate the dispersion of pollutants in relation to their main sources, therefore urban sites were chosen as well as industrial and rural sites. Such a monitoring plan allowed an investigation on the spatial and temporal variation of typology and amount of the detected substances. As a result, urban sites, relatively far from vinicultural areas, showed to be contaminated by pesticides; on the other hand, samples collected in open land areas showed different levels of contamination by PAHs. Pesticides could be detected only during the application time (spring and summer), while PAHs, due to the characteristics of the emitting sources, could be detected during the whole period of monitoring.