China’ s first exploration of Chukchi Sea and its adjacent waters in the arctic — A study on lead geochemistry of atmospheric aerosol

The Pb concentrations of atmospheric aerosol in the Chukchi Sea of the Arctic vary within the range of 0.167–0.962 ng/m3, with an average of 0.532 ng/m3. These concentration values are 200 times higher than the natural background values of snow samples there. Calculation of the Pb enrichment factor of aerosol indicates that the ocean- and continent-source lead account for 9.23% and 0.01%, respectively, but industrially released Pb accounts for more than 90% of the atmospheric Pb. The Pb isotopic composition of aerosol has revealed that the sources of lead from industrial lead that causes pollution include mainly the western part of North America, East Europe and the former Soviet Union. The calculation of the total fallout flux of Pb indicates that the mean value of input flux into the Chukchi Sea is 0.02 mgm-2 a-1, equivalent to that of southern Pacific but slightly lower than that of northern Indian Sea and southern Atlantic. It is evidenced that the Pb input flux into the Chukchi Sea is far lower than that off the Baltic Sea, the North Sea and the Mediterranean Sea.