Polychlorinated biphenyls in the air of southern Sweden – spatial and temporal variation

Polychlorinated biphenyls in the lower atmosphere were studied over a regional area covering approximately 11 000 km2 in southern Sweden. Sampling were performed in 1992–1993, continuously during one year, where samples from 11 sampling-sites (in all 260 samples) were analysed. PCB concentrations ranged over two order of magnitudes, 7–983 pg m−3. Differences in PCB concentrations among the sampling sites revealed a large number of high-concentration outliers, mainly originating from one suburban site. Smaller differences in PCB concentrations between sites probably originated from varying geographical and meteorological conditions, that affected exchange processes between air and surfaces differently at the sampling sites.