Semi-volatile organic chemical pollutants (SOCs) accumulate and persist in the environment, particularly in cold environments such as polar and alpine regions. These pollutants (SOCs) include previously banned or restricted organochlorine compounds (OCs) such as polychlorinated biphenyls (PCBs), which are manmade chemicals that have been used widely in electrical equipment such as capacitors, as well as in paint, sealants and flame retardants. The semi-volatile nature of these pollutants mean that they can travel long distances by air. This study examines the processes of transport, deposition and degradation of SOCs in four alpine European sites.