Publication Abstract

Atmospheric transport, cycling and dynamics of polychlorinated biphenyls (PCBs) from source regions to remote oceanic areas

Rosalinda Gioia*,Jordi Dachs, Luca Nizzetto, Rainer Lohmann and Kevin C Jones

Polychlorinated biphenyls (PCBs) are ubiquitous in the environment. Their persistence coupled with their potential toxicity has prompted international regulations and increased effort to understand their regional and global scale presence, and the processes that influence their fate and transport. PCBs can travel in the atmosphere away from source regions through long-range atmospheric transport and be deposited to water and terrestrial surfaces. This chapter focuses on the atmospheric concentrations of PCBs and factors controlling their spatial and temporal variability from source regions to oceanic remote areas. Air data show a strong latitudinal trend with the highest PCB concentrations in Europe and the lowest in the Arctic and in the tropical and subtropical southern hemisphere. High PCB levels were observed off the west coast of Africa and Asia, and possible factors controlling these high levels and their implications for the global cycling of PCBs are discussed. Furthermore, air-water interactions are disussed in remote areas of the open ocean. Of particular importance is the evidence for near steady-state air-water equilibrium or net volatilization in the tropical and subtropical regions, while advective inputs still dominate in the Northern hemisphere. Net deposition dominates over volatilization in the Arctic region. This chapter seeks o examine recent findings in the global transport of PCBs and to identify areas of uncertainty in the understanding of the factors controlling the residence time of PCBs in different areas of the globe.