Díaz-Somoano M, Kylander M E, López-Antón M A, Suárez-Ruiz I, Martínez-Tarazona M R, Ferrat M, Kober B, Weiss D J
Instituto Nacional del Carbón (INCAR-CSIC), Oviedo 33011, Spain.
Environ Sci Technol. 2009 Feb 15;43(4):1078-85. doi: 10.1021/es801818r.
The phasing out of leaded gasoline in many countries around the world at the end of the last millennium has resulted in a complex mixture of lead sources in the atmosphere. Recent studies suggest that coal combustion has become an important source of Pb in aerosols in urban and remote areas. Here, we report lead concentration and isotopic composition for 59 coal samples representing major coal deposits worldwide in an attempt to characterize this potential source. The average concentration in these coals is 35 microg Pb g(-1), with the highest values in coals from Spain and Peru and the lowest in coals from Australia and North America. The 206Pb/207Pb isotope ratios range between 1.15 and 1.24, with less radiogenic Pb in coals from Europe and Asia compared to South and North America. Comparing the Pb isotopic signatures of coals from this and previous studies with those published for Northern and Southern Hemisphere aerosols, we hypothesize that coal combustion might now be an important Pb source in China, the eastern U.S., and to some extent, in Europe but not as yet in other regions including South Africa, South America, and western U.S. This supports the notion that "old Pb pollution" from leaded gasoline reemitted into the atmosphere or long-range transport (i.e., from China to the western U.S.) is important. Comparing the isotope ratios of the coals, the age of the deposits, and Pb isotope evolution models for the major geochemical reservoirs suggests that the PbIC in coals is strongly influenced by the depositional coal forming environment.
上世纪末，世界上许多国家逐步淘汰含铅汽油，导致大气中铅源构成复杂。近期研究表明，煤炭燃烧已成为城市和偏远地区气溶胶中铅的重要来源。在此，我们报告了代表全球主要煤田的59个煤样的铅浓度和同位素组成，旨在表征这一潜在来源。这些煤中铅的平均浓度为35微克/克，西班牙和秘鲁的煤中铅含量最高，澳大利亚和北美的煤中铅含量最低。206Pb/207Pb同位素比值在1.15至1.24之间，与南美和北美相比，欧洲和亚洲煤中的铅放射性较低。将本研究及先前研究中煤的铅同位素特征与北半球和南半球气溶胶的铅同位素特征进行比较，我们推测，煤炭燃烧现在可能是中国、美国东部以及在一定程度上欧洲的重要铅源，但在包括南非、南美和美国西部在内的其他地区目前还不是。这支持了这样一种观点，即含铅汽油排放到大气中的“旧铅污染”或长距离传输（即从中国传输到美国西部）很重要。比较煤的同位素比值、矿床年龄以及主要地球化学储库的铅同位素演化模型表明，煤中的铅同位素组成受沉积成煤环境的强烈影响。
