Transboundary transport of atmospheric pollutants through the Eastern Alps

Some preliminary analyses have shown that the Brenner Pass can be important in the transport of atmospheric pollutants through the Alpine chain, due to either breeze circulation or inflows of air masses. In one cross-section of the valley near the pass, meteorological and chemical measurements were taken, starting in 1986. The local breeze was studied but it was recognized to be of minor importance. The transport of pollutants through the pass was, on the whole, modest except during some inflows that only lasted for a few days. Meteorological situations have been registered when windborne pollutants are transported either to or from Italy, as was recognized from the trajectory analysis. The air masses coming in from central and eastern Europe generally contain higher concentrations of SO2 than NO2, while the opposite is true when the air masses originate in the Po Valley where the large use of methane enriches the air with NO2.