LEAD IN THE WESTERN NORTH-ATLANTIC OCEAN - COMPLETED RESPONSE TO LEADED GASOLINE PHASEOUT

A 16-year time series of lead concentrations in the western North Atla ntic Ocean shows that lead concentrations decreased markedly during th e 1980s but that the decline slowed in the 1990s. The decrease during the 1980s can be attributed to the phasing out of leaded gasoline in t he United States. Lead concentration levels of the 1990s may be suppor ted by emissions from high temperature industrial activities in the US A rather than by residual leaded gasoline emissions. Lead concentratio ns in the thermocline above similar to 700 m depth have continued to d ecrease over this time period. Further decreases in surface water Pb c oncentrations may be minimal in coming decades, but continued propagat ion and evolution of the lead distribution in deeper waters should be expected. Copyright (C) 1997 Elsevier Science Ltd.