Lead contamination and transfer in urban environmental compartments analyzed by lead levels and isotopic compositions

摘要

Lead levels and isotopic compositions in atmospheric particles (TSP and PM_(2.5)), street dust and surface soil collected from Nanjing, a mega city in China, were analyzed to investigate the contamination and the transfer of lead in urban environmental compartments. The lead contents in TSP and PM_(2.5) are significantly higher than them in the surface soil and street dust (p < 0.05). The enrichment factor using the mass ratio of lead to the major crustal elements (Al, Sr, Ti and Fe) indicates significant lead enrichment in atmospheric particles. The plots of ~(206)Pb/~(207)Pb vs. ~(208)Pb/~(206)Pb and ~(206)Pb/~(207)Pb vs. 1/Pb imply that the street dust and atmospheric particles (TSP and PM2.5) have very similar lead sources. Coal emissions and smelting activities may be the important lead sources for street dust and atmospheric particles (TSP and PM_(2.5)), while the deposition of airborne lead is an important lead source for urban surface soil.