Tracing Source Pollution in Soils Using Cadmium and Lead Isotopes

Abstract

Tracing the source of heavy metals in the environment is of key importance for our understanding of their pollution and natural cycles in the surface Earth reservoirs. Up to now, most exclusively Pb isotopes were used to effectively trace metal pollution sources in the environment. Here we report systematic variations of Cd isotope ratios measured in polluted topsoils surrounding a Pb-Zn refinery plant in northern France. Fractionated Cd was measured in soil samples surrounding the refinery, and this fractionation can be attributed to the refining processes. Despite the Cd isotopic ratios being precisely measured, the obtained uncertainties are still large compared to the total isotopic variation. Nevertheless, for the first time, Cd isotopically fractionated by industrial processes may be traced in the environment. On the same samples, Pb isotope systematics suggested that materials actually used by the refinery were not the major source of Pb in soils, probably because refined ore origins changed over the 100 years of operation. On the other hand, Cd isotopes and concentrations measured in topsoils allowed identification of three main origins (industrial dust and slag and agriculture), assuming that all Cd ores are not fractionated, as suggested by terrestrial rocks so far analyzed, and calculation of their relative contributions for each sampling point. Understanding that this refinery context was an ideal situation for such a study, our results lead to the possibility of tracing sources of anthropogenic Cd and better constrain mixing processes, fluxes, transport, and phasing out of industrial input in nature.

A simple combined sample–standard bracketing and inter-element correction procedure for accurate mass bias correction and precise Zn and Cu isotope ratio measurements

“…Precisions achieved are in line with reports from other laboratories and/or different instruments 3,4,12,14 and at least 20 times less than natural variability. 22 The mass fractionation coefficients measured on the IsoProbe (2.34 AE 0.02 for f Cu and 2.44 AE 0.02 for f Zn ) are similar to those measured on another MC-ICP-MS instrument, the Plasma 54 (2.1 AE 0.1). 3 We also find that f Zn is systematically and significantly higher than f Cu (i.e., f Cu a f Zn ).…”

Assessing heavy metal pollution in the surface soils of a region that had undergone three decades of intense industrialization and urbanization

“…It should be noted that although the simple multivariate analyses (e.g., PCA and CA) and correlation matrix used in this study provide important information on the potential sources of heavy metals, better statistical and geochemical tools are necessary for apportioning the contributions of natural and anthropogenic sources to the soil heavy metal Fig. 4 The potential ecological risk of soil heavy metal pollution in the PRD: a Contributions of individual heavy metals to the mean potential ecological risk of the surface soils; b Potential ecological risk levels of heavy metals in the surface soils from lands of different use types; and c The spatial distribution of the potential ecological risk level pollution (Cheng and Hu 2010a;Cloquet et al 2006;Hu and Cheng 2013;Kubosova et al 2009;Vega et al 2009;Zhang et al 2008). Additional characterization of the soil properties (such as soil total organic carbon and available phosphorus) could further help discriminate the natural and anthropogenic contributions on soil heavy metal pollution.…”

Exploring green criminology: toward a green criminological revolution

“…Certainly, the methods used by environmental toxicologists have a role to play in the investigation of environmental crimes. These methods, for example, can be used to trace pollutants through environmental media or to their sources (for example, Cloquet et al, 2006;Fatta, Nikolaou, and Meric, 2007;Schaper and Jofre, 2000). But there is another important issue that we need to raise because we will expand upon this observation later in this chapter.…”