engleski

Regional trends of pops in European ambient air

Air is an important transport medium for PTS in general. Reporting ambient air concentrations reflects the concentration during the sampling period but, due to rapid transport and fast mixing of pollutants in air, PTS concentrations will change quite rapidly. Heavy metals and persistent organic pollutants (POPs) were included in EMEP’ s monitoring programme in 1999. However, by 1995, co-operation concerning heavy metals and POPs between EMEP and other international programs was extended. This co-operation included the establishment of a database and collection of already available data on POPs among the participants. A number of countries have been reporting POPs within the EMEP area in connection with different national and international programmes such as HELCOM, AMAP, OSPARCOM, MEDPOP. Few of the sites have reported data for POPs to date in the atmosphere. The stations are generally located distant from local emission sources in order to be representative for a larger region. Regional concentrations and deposition fluxes of selected POPs and the spatial and temporal variation across Europe have been investigated. The sites included were Košetice in the Czech Republic in central Europe, Rörvik, which is a coastal station at the Swedish West Coast, Pallas, a sub-arctic area in northern Finland and Preila in Lithuania at the Baltic Sea. In the Netherlands, measurements of selected POPs in air and precipitation have also been carried out for a period of two years at 18 stations including one at the sea. A seasonal variation in the atmospheric concentrations of POPs was found at all the sampling sites, but the concentrations also varied as a result of the origin of the air masses. The highest PAH levels occurred during the winter periods, while the levels of PCBs and pesticides were higher during warmer periods. No significant time trend was observed in the annual averages for PCB and PAH but there were indications of slightly declining levels, especially for individual components, which is demonstrated for PCB – 153 at the two sampling sites Rörvik and Pallas .

POPs, air

nije evidentirano