Lead isotope ratios in Spanish coals of different characteristics and origin

Abstract

Lead isotope ratios in coals of different rank from several Spanish basins were estimated and related with their characteristics. The isotope 206 Pb/ 207 Pb ratio values of the coals studied range between 1.13-1.21, with the exception of some coal samples from the Cretaceous which are more radiogenic. Coals were classified into groups according to their lead isotope ratios. These in turn were related to the isotope ratios of the minerals galena, pyrite, chalcopyrite, and carbonates. Some of the low-rank coals, in which lead might be expected to be associated to the organic matter, were not found to be related with isotope ratios of minerals. The isotope ratios of the individual densimetric fractions separated from a bituminous coal are different to those of the raw coal. The differences between these isotope ratios may not only be due to the diverse origin of lead in different coals, but also to the possible presence of several lead species incorporated from various sources in a particular coal. The results of this work represent an important contribution to the lead isotope ratio database essential for the accurate interpretation of data regarding pollution sources.

Lead isotope ratios in a soil from a coal carbonization plant

“…The lead isotope ratios for the different samples and standards are given in close to those of a contaminated soil (LGC6138) and similar to the isotope ratios of Spanish coals [16]. These results corroborate the view that coal carbonization is the source of lead in the soil samples with the highest lead content.…”

“…In fact, stable Pb isotopic ratios, in combination with concentration data for Pb, are a useful method for differentiating natural from anthropogenic lead and discovering sources of Pb contamination [8][9][10][11][12]. Data on lead isotope ratios for different ores and pollution sources, including some coals, are already available in the literature [7,[11][12][13][14][15][16][17], and may be used for comparing isotope ratios in possible contaminated sites.…”

Stable isotopes in environmental investigations

“…Recent studies suggest [33][34][35][36] that coal combustion has become an important source of Pb in aerosols in urban and remote areas. Accordingly, lead isotopic ratios are used for tracing the urban atmospheric aerosols [37].…”

Nuclear forensic science—From cradle to maturity

“…The isotopic composition of lead is a parameter that has been noticed to vary as a function of the U mine to another or more generally from one source to another [14][15][16][17][18][19][20]. Three out of four of the stable Pb isotopes, namely 206 Pb, 207 Pb and 208 Pb, are the end products of the radioactive decay series of 238 U, 235 U and 232 Th, respectively.…”

“…The third possible signature for geolocation is the isotopic ratio of 18 [22,23]. There are several parameters, which cause variations of around 5% in the oxygen ratio, such as temperature, latitude and distance to the sea.…”