The IsoCont contains 7 WPs. Priority issues in relation to atmospheric Hg dynamics (WP1), methylation in oceanic environment (WP2), and terrestrial Hg dynamics (WP3) form the set of three WPs that are supported by a horizontal WP4 dealing with metrological/analytical aspects. The purpose of WP1 is to address the dynamic atmospheric Hg species with the aim to improve knowledge of important redox reaction species in the atmosphere water and the transformation processes and dynamic transport systems. WP2 will make quantitative assessments of MMHg and DMHg origin and transformations in coastal marine environments. The WP3 will address specific aspects of the role of terrestrial Hg pools and its exchange with the atmosphere and aquatic compartments based on the previously identified knowledge gaps. It will generate process-based understanding of mobility of Hg from soil and the role of canopy and foliar Hg exchange. To reach the above objectives, analytical developments in WP4 will improve comparability of measurement results by providing traceable calibration standards and to develop novel sensors for the bioavailable fraction of Hg. Novel analytical developments are also included within each of the WP 1-3, in particular in relation to the use of the state-of-the-art stable isotope technologies. The work will explore, for the very first time, simultaneous mercury, carbon and hydrogen isotope signatures of the MMHg molecule in the marine foodweb. We shall refine and apply calibration of instruments and methods for Hg speciation measurement in air, based on metrological traceability to the international system of units (SI). This will allow better insights into chemical species of oxidized Hg. IsoCont will use approaches to better understand the formation of oxidized Hg species in the atmosphere. This will provide a theoretical understanding of the actual nature of Hg species in the atmosphere to support the activities related to testing, optimizing and validation of sampling protocols. IsoCont will lead to a better understanding of the contribution of contaminated sites to the global exchange of Hg between different environmental compartments. Empirical and modelling assessments of the exchange processes will be conducted, and new knowledge integrated in the coupled models and policy scenarios being developed in modeling WP5.

Moreover, close collaboration with the authorities in the local regions and communication activities planned (WP6) will improve the methodological approaches and scenarios chosen for the remediation of this wide spread contamination site. WP7 is described elsewhere

isocont wps2