State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73, East Beijing Road, Nanjing, 210008, China,
Environ Sci Pollut Res Int. 2013 Dec;20(12):8739-50. doi: 10.1007/s11356-013-1861-0. Epub 2013 Jun 2.
Atmospheric lead (Pb) pollution during the last century in central Yunnan province, one of the largest non-ferrous metal production centers in China, was reconstructed using sediment cores collected from Fuxian and Qingshui Lakes. Lead concentrations and isotopic ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb) were measured in sediment cores from both lakes. The operationally defined chemical fractions of Pb in sediment core from Fuxian Lake were determined by the optimized BCR procedure. The chronology of the cores was reconstructed using (210)Pb and (137)Cs dating methods. Similar three-phase variations in isotopic ratios and enrichment factors of Pb were observed in the sediment cores from both lakes. Before the 1950s, the sediment data showed low (207)Pb/(206)Pb and (208)Pb/(206)Pb ratios and enrichment factors (EFs=~1), indicating that the sedimentary Pb was predominantly of lithogenic origin. However, these indices were increased gradually between the 1950s and the mid-1980s, implying an atmospheric Pb deposition. The EFs and isotopic ratios of Pb reached their peak during recent years, indicating aggravating atmospheric Pb pollution. The average anthropogenic Pb fluxes since the mid-1980s were estimated to be 0.032 and 0.053 g m(-2) year(-1) recorded in Fuxian and Qingshui cores, respectively. The anthropogenic Pb was primarily concentrated in the reducible fraction. Combining the results of Pb isotopic compositions and chemical speciations in the sediment cores and in potential sources, we deduced that recent aggravating atmospheric Pb pollution in central Yunnan province should primarily be attributed to regional emissions from non-ferrous metal production industries.
采用沉积物柱状样，对抚仙湖和清水海湖泊沉积物中的 Pb 浓度和同位素比值（((207)Pb/(206)Pb 和 (208)Pb/(206)Pb）进行了测试，以重建上个世纪云南中部大气 Pb 污染情况，该地区是中国最大的有色金属生产中心之一。采用优化的 BCR 程序，对抚仙湖柱状样中 Pb 的化学形态进行了测试。利用 (210)Pb 和 (137)Cs 定年方法，重建了柱状样的年代。抚仙湖和清水海柱状样中 Pb 的同位素比值和富集因子均表现出相似的三相变化特征。在 20 世纪 50 年代之前，沉积物数据显示出低的 (207)Pb/(206)Pb 和 (208)Pb/(206)Pb 比值和富集因子（EF=~1），表明沉积 Pb 主要来源于岩石成因。然而，在 20 世纪 50 年代至 80 年代中期，这些指数逐渐增加，表明大气 Pb 沉降。近年来，Pb 的 EF 和同位素比值达到峰值，表明大气 Pb 污染加剧。自 20 世纪 80 年代中期以来，抚仙湖和清水海柱状样中记录的人为 Pb 通量分别为 0.032 和 0.053 g m(-2) year(-1)。人为 Pb 主要集中在可还原相中。综合沉积物柱状样中 Pb 同位素组成和化学形态以及潜在源区的结果，我们推断云南中部地区近年来大气 Pb 污染的加剧主要归因于有色金属生产行业的区域排放。
