ABRUPT DECREASE OF LEAD CONCENTRATION IN THE MEDITERRANEAN-SEA - A RESPONSE TO ANTIPOLLUTION POLICY

In the Northwestern Mediterranean basin, lead concentrations in the su rface waters have halved over the last 10 years. This decrease followe d successive limitations of the use of lead additives in gasoline occu rred in European countries since 1976 and the progressive use of unlea ded fuel. The evolution of lead concentration in the Mediterranean wat ers is simulated by using a geochemical six-box model and validated by measurements made since 1983. In this way, it is demonstrated that: i ) previous major pollution was essentially lead gasoline derived; ii) international antipollution policy is efficient; iii) the Mediterranea n Sea is an important case study area to assess the marine biosphere's response to environmental changes.