ABSTRACT

In this study, we measured the lead isotope ratios as well as trace metal concentrations (As, Cd, Cr, Ni, Pb and Zn) in the airborne particles collected at the Tokyo metropolitan area, where 9 municipal solid waste (MSW) incinerators locate nearby. Relationship between the concentrations of lead and other trace metals was investigated using data obtained both at the study site and at the 16 monitoring stations of the National Air Surveillance Network (NASN) of Japan sited mainly in urban areas. The results showed that lead isotope ratios were almost constant at the study site. The lead isotope ratios were very close to those for 7 cities throughout the whole country and also the fly ashes from MSW incinerators. This means that MSW incineration can account for the major portion of the lead in most Japanese urban atmosphere. The results also suggested that there are no significant differences in the concentration ratios of Cd, Zn and As to Pb in the airborne particles emitted from MSW incinerators across the country. Based on these results, the contributions from MSW incineration to the atmospheric metal concentrations were estimated to be 94% for Cd, 78% for Zn and 71 % for As.