CARBPOL · Investigating the role of the carbon cycle on the environmental fate of semivolatile organic pollutants

Investigating the role of the carbon cycle on the environmental fate of semivolatile organic pollutants

Project context and objectives CARBPOL focused on the investigation of the mechanisms underpinning the relationship between environmental fate and the occurrence of anthropogenic chemical pollutants and natural biogeochemical cycles, with particular focus on the carbon cycle and the persistent organic pollutants (POPs). This topic is currently of central interest for an international community of researchers. Legacy POPs encompass a heterogeneous class of toxic chemical substances that were produced and emitted in large quantities throughout the 20th century. As a result of their physical chemical properties they became global pollutants of concern due to their bioaccumulation potential and their toxicity. Large quantities of POPs emitted in the past are currently stored in environmental capacitors worldwide, mainly carbon-rich compartments such as soil and vegetation. The international community has undertaken important initiatives to limit/ban the production of POPs and reduce primary emissions. However, changes in environmental conditions (especially those related to climate change) could potentially remobilise the environmental burden, thus renewing an old problem. CARBPOL's overall goal was to bring this argument to the interest of the international community and develop focused research aimed at quantitatively characterising the relationship between the fate of POPs and the biogeochemical drivers controlling the incorporation and re-emission from the environmental reservoirs. Work performed A key output of the project is the feature paper ‘Past, present and future controls on the levels of persistent organic pollutants in the global environment’ (Nizzetto et al. 2010). This paper resulted from an international symposium (sponsored by the European Science Foundation, and published with a dedicated cover page in 'Environmental Science and Technology'), which reviewed the current understanding on the relationship between direct primary emission and re-emission from environmental capacitors. Using dynamic multimedia modelling, it was estimated that currently more than 50 % of the annual emission of POPs circulates in the environment and is co-transported with organic carbon (e.g. through uptakes in growing vegetation, litter deposition, deposition of organic particles in the atmosphere, settling of organic particles in water, etc.). This result corroborates the importance of developing a mechanistic understanding of the coupling between chemical fate processes and biogeochemical cycles. A large part of the activity of CARBPOL was dedicated to the investigation of these mechanisms. This research encompassed focused studies in key ecosystems or specific case scenarios, such as different type of forests and selected water ecosystems. In particular we worked on characterising the dynamic relationships between primary production and air-to-surface or water-to-biomass exchanges of chemical pollutants. For these specific processes we developed mechanistic models, which were used to anticipate the environmental conditions under which the re-emission of chemicals from environmental reservoirs may occur. Main results Important outcomes of the project are the new mathematical models that were developed by coupling existing ecological model frameworks and applying these to the chemicals’ environmental fate. The topic area of CARBPOL is of growing interest for the international research communities and currently a number of international projects are focusing on the same aspects. We believe that the scientific literature generated by this project (published in the major international journals of this field) will constitute an important contribution to the future development of the research area.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз