Mercury Pollution

Recent news of mercury contamination in the Priolo-Agusta-Melilli industrial zone (Sicily) brought to public attention the seriousness of mercury pollution on human health and ecosystems. Mercury pollution is a long standing environmental problem, going back to the 19th century, starting with mercury used in gold extraction in North America; this practice is still widely used in Laos, Vietnam, Tanzania and Venezuela today. Mercury is much used in the manufacturing industry (eg., chlor-alkali plants) and is found in many everyday goods (i.e., thermometers, electrical devices, medical equipment). Globally, nearly 5000 metric tons of mercury are released to the atmosphere each year, 50% is due to industrial emissions, the rest is from natural sources (i.e., the oceans, volcanoes). Trend analysis of emissions over the last 20 years show an increase and suggests that fast developing countries (i.e., China, India) are the main contributors (40%). Atmospheric mercury is transferred to aquatic and terrestrial receptors via a complex combination of transport and transformation processes potentially harming human health and ecosystems. Over the last seven years the Division of Rende of the CNR Institute for Atmospheric Pollution (CNR-IIA) has carried out international and European research projects to understand mercury dynamics in the Mediterranean, as well as in the Arctic and Antarctic ( The European Commission Position Paper on Mercury (PP) ( showed how serious the consequences of mercury contamination are in and outside Europe.
Recent findings published by CNR-IIA researchers show that mercury pollution in the Mediterranean is more serious than elsewhere in Europe and other parts of the world. Regional scale atmospheric transport is certainly an important factor, however, chemical and physical processes occurring in the Marine Boundary Layer of the Mediterranean are just as important in the formation of more soluble forms of mercury (oxidised mercury) which deposit to marine ecosystems during precipitation events; air-water exchange processes are also important in the overall cycling of mercury between air and sea.
We need to ask, and answer, questions regarding the qualitative and quantitative relationships between atmospheric input (deposition), and Hg in aquatic environments. Is it possible to establish a mercury deposition limit in order to regulate atmospheric emissions? What is the relationship between mercury flux to surface waters and the mercury (methyl mercury) levels in fish? How can the response time marine ecosystems to changes in atmospheric emissions be evaluated? Unfortunately the answers to these questions are still uncertain. The need for further research in Europe on different aspects of mercury pollution including its fate in the environment and ultimately its impact on human health and ecosystems have been forwarded to the European Commission as recommendations of the PP and to UNEP for the next UNEP Governing Council in February 2005.