Polychlorinated Biphenyls (PCBs) Atmospheric Concentrations and Deposition in Sub-Alpine Northern Italy

Abstract

Atmospheric transport and deposition are important processes determining the fate of many persistent organic pollutants (POPs) in the environment. Research has been carried out in the last decades on ambient concentrations and controls of numerous POPs families. Experimental measurements alone (active and passive sampling) or combined with model estimations have been used to study the POPs environmental processing, transport and behavior in specific regions. However, there are many areas for which little or no information on POPs ambient levels is available. Such is the case with Southern-Western Europe, that remains uncovered by the EMEP POPs monitoring network. Moreover, the scarcity of consistent experimental data sets on atmospheric concentrations poses a problem for proper validation of models. Our main objective was to initiate POPs atmospheric measurements (weekly resolution) in order to assess air concentrations and seasonal variations of selected POPs in a sub-alpine location where little information is available on POPs ambient levels. To achieve this goal, a monitoring and research station was set up at the Joint Research Centre EMEP site (Ispra, Italy). We present and discuss a one year data set (2005-2006) on PCB air concentrations (gas and particulate phases). ¿7PCBs monthly averaged concentration varied from 31-76 pg m-3. These values are within the range of those reported for rural, semi-rural or remote areas around the world. Advection of air masses and re-volatilization from local sources seem to play a dominant role as drivers of PCB atmospheric concentrations in the area. The importance of the wet deposition in this region (1 ug m-2 yr-1 ¿7PCBs yearly total wet deposition flux; 650-2400 pg L-1 rainwater concentrations) is emphasizedJRC.DDG.H.5-Rural, water and ecosystem resource