OXYGEN AND SULPHUR ISOTOPE DYNAMICS IN THE SO2−4 OF AN URBAN PRECIPITATION
Two years monitoring of acid rain sulphate (25 samples) in downtown Wrocław (SW Poland) was carried out. A significant increase in δ34S (SO2−4) corresponded to a negligible increase in δ18O (SO2−4) and decrease in concentration of sulphate, respectively. Two periods, before and after June 1994, corresponding respectively to low and high δ34S (SO2−4) values have been observed. These patterns may result dominantly from a significant reduction in the emission of 34S-depleted SO2 due to: (i) new installations in the neighbouring heating plant and/or in the Głogów sulphide-based copper smelting works, as well as (ii) the fact that a brown-coal power plant has been phased out in Eastern Germany. The results obtained together with possible subsequent observations (several years) could be an important basis to calibrate a new toll for reconstruction of anthropogenic impact.