Pattern Analysis of Polychlorinated Biphenyls (PCB) in Marine Air of the Atlantic Ocean

Abstract
The patterns of polychlorinated biphenyls (PCB) in marine air samples of the North- and the South Atlantic were compared to each other by a congener ratio correlation, by the similarity index, which was calculated by two different algorithms, and by principal component analysis (PCA). The calculations were done on the basis of the following fourteen PCB congeners: the trichlorobiphenyls PCB 28, PCB 31, the tetrachlorobiphenyls PCB 44, PCB 49. PCB 52, the pentachlorobiphenyls PCB 87, PCB 101, PCB 110, PCB 118, the hexachlorobiphenyls PCB 138, PCB 149, PCB 151, PCB 153 and the heptachlorobiphenyl PCB 180. The three methods gave basically the same results. The use of only the seven indicator PCB congeners 28, 52, 101, 118, 138, 153 and 180 did not alter the pattern classification of the samples. There exists a typical marine clean-air PCB pattern in the lower troposphere of the Atlantic Ocean between 40[ddot] North and 40[ddot] South, which apparently reflects the air/sea water equilibrium. This marine clean-air pattern is significantly different from a pattern of marine air samples influenced by continental air masses coming in from Europe or South America. This influence is marked by an increase of the levels of the higher chlorinated congeners. The PCB patterns in continental air samples from western Europe and the Great Lakes region in North America differ in their portion of lower chlorinated congeners.