An Integrated Approach to Assess the Mercury Cycle into the Mediterranean Basin (MERCYMS)
Finanziamento: European Commission, DG Research – 5th Framework Programme
Periodo: 1 October 2002-30 November 2005
Budget totale progetto:---
Budget totale CNR IIA:---
Responsabile Scientifico: Nicola Pirrone

Abstract del progetto

In recent years the European Union has started the process of reshaping its environmental policy by launching the Framework Water Directive and the Air Quality Directive for major pollutants. Special attention is devoted to those pollutants that are persistent in air, water and soil ecosystems with different residence times and have a significant impact on human health and the environment. Mercury is a pollutant of major concern in Europe due primarily to its high toxicity and persistence in the environment. In fact, once released to soil, water and atmospheric ecosystems from a multitude of natural and anthropogenic sources, it can be re-distributed in the environment through a complex combination of chemical, physical and biological processes that can act with different time scales. Therefore, the implementation of these directives requires a continuos progress in our knowledge of all those mechanisms that may effect the cycling of mercury between air, water and soil ecosystems. Past and recent studies carried out in the Mediterranean Sea show that the contribution of the air-sea exchange in the overall mercury cycle between the atmosphere and marine waters can be significant.

Based on these preliminary estimates, there is a general agreement in the scientific community that the marine ecosystem can be a sink and/or source of the mercury that is cycling in the global environment, and current estimates of the global mercury budget for the Mediterranean region are affected by high uncertainty. This uncertainty is primarily due to the little progress made so far in evaluating the role of chemical, physical and biological processes in the water system and in the lower atmosphere above the sea water (air-water interface). The dynamics of water waves have also been shown to play an important role in the global mercury cycle. However, the relationship between the atmospheric input – the cycle in the marine environment and the re-emissions back to the atmosphere is not yet fully understood.

Anthropogenic activities presumably increased the surface water marine Hg concentration by a factor three, an increase which resulted amongst others in elevated Hg concentrations in marine fishes. It is currently thought that most of the methylated Hg found in the water column and the biota of the marine waters is generated by in-situ production, though the reaction mechanisms are not yet clearly understood.
The overall goal of MERCYMS is to fill the gaps firstly specificated and develop a Practical Working Tool (PWT) for a wide spectrum of users (i.e., policy makers, environmental planners) that would allow to assess for different environmental conditions and socio-economic scenarios, the relationship between the atmospheric input of mercury and its compounds to the Mediterranean Sea and the formation/production of the most toxic forms of mercury (i.e., MMHg, DMHg) in the marine system which have a significant impact on human health and the environment.

Specific objectives of MERCYMS are:
To improve our capabilities in modeling the fate of Hg in the marine environment, specifically to assess the translocation of major Hg compounds from one compartment to the other taking into account the role of major chemical, physical and biological processes.
To assess the qualitative and quantitative relationships between atmospheric input – direct discharges to the sea from land-based point and diffuse sources – the cycle of Hg in the marine environment and its re-emission back to the atmosphere. A clear knowledge of these relative contributions will support the validation phase of the European Directives.
To develop an integrated modeling framework for assessing the magnitude of key parameters describing the cycle of mercury between the Mediterranean Sea and the atmosphere. It will be a merger of an atmospheric modeling system and a water modeling system. This integrated modeling framework will be evolved into a practical working tool for a wide spectrum of users (i.e., EU Commission, fish industry, policy makers, environmental planners) in order to be applied/adopted for different scenarios of environmental policy. The PWT will be based on the concept of the Driver-Pressure-State-Impact-Response (DPSIR) Framework.
To apply this modeling framework for assessing the magnitude of different processes involved in the cycle of mercury and its exchange (net flux) between the surface seawater and the atmosphere under different environmental conditions and socio-economic scenarios. The scenarios that will be considered in this assessment will be derived primarily by the driving principles of the EU Air Quality Directive and EU Water Framework Directives, International Conventions.
CNR Institue of Environmental Pollution Research (CNR-IIA) – COORDINATORE

Sergio Cinnirella

Franco Cofone

Ian M. Hedgecock

Maria Orrico

Francesca Sprovieri