Persistent Organic Pollutants (POPs) in the European Atmosphere: An Updated Overview

POPs are a group of chemicals which share some specific characteristics that make them of high international concern. Due to their semivolatility, POPs present a widespread distribution being able to reach remote locations and areas after traveling long distances in the atmosphere where they have never been produced nor used. Different chemical families are considered as POPs, such as PCBs, OCPs, PCDD/Fs, PAHs, and, PCNs. In addition, some emerging contaminants are currently considered as candidate POPs, like PBDEs and PFCs. POPs exist in the atmosphere as gases and bound to particles depending on their physico-chemical properties. This affinity to gas or particulate phase is of relevant importance in the processes of POP atmospheric global transport and degradation. POPs are delivered to aquatic and terrestrial ecosystems by atmospheric deposition, air-water interchanges and direct discharges. The general hydrophobic nature of POPs results in high affinity to organic matter and biota tissues. Consequently, organisms and sediments become final “sinks” of POPs, due to the low metabolic activity for these compounds and their slow degradation processes in the environment. A number of national and international actions have been promoted to reduce or ban their production and control their emissions to the environment. The UNEP Stockholm Convention adopted in May 2001. The Artic Monitoring and Assessment Programme (AMAP) is measuring atmospheric concentrations of POPs in the artic region since it was established in 1991. At a European scale a big effort is being carried out combining the update of existing monitoring programmes with the generation of new legislations. Such is the case of the largest monitoring network across Europe gathering concentrations of POPs in air and deposition (EMEP). On the political side, the brand new European legislation on chemicals, REACH, will regulate the production of chemicals at a European scale. In addition, other POPs monitoring programmes exist at regional or national scales and a large number of “independent” sites measuring atmospheric concentrations of POPs are spread out in the European geography. Considering such a scenario it seems obvious that a strong effort in harmonization and communication of results and monitoring and research strategies needs to be achieved. A step to facilitate this needed interaction was the workshop on “Persistent Organic Pollutants (POPs) in the European Atmosphere – Concentration, Deposition and Sources in Europe –“ organized by the European Commission Joint Research Center held in October 17-19, 2005 in Stresa (Italy). It was one of the objectives of the workshop to gather top experts from Europe and North America to share their expertise on POP monitoring and research in the atmospheric compartment in order to evaluate their current status in Europe. Invited experts develop their professional activities either in the existing POPs monitoring networks or in research institutions closely linked to POPs research (Annex I). Other objectives of the workshop were to