# Can Isotopes Be Used as Lead Tracers in Shooting-Range Soils?
## 3 Results and Discussion  
We found that stable isotope ratios for studied soils ranged between 1.123 and 1.1709 for \({}^{206}\)Pb/\({}^{207}\)Pb and between 2.084 and 2.134 for \({}^{208}\)Pb/\({}^{206}\)Pb (Table 1). These values were very similar to values indicated by [5] for lead isotopes from hunting areas in Spain and within the range stated by [12] for agricultural soils contaminated by civilian shooting activities in the Czech Republic. However, these values were lower than those reported by [22] for military soils in South Korea, with \({}^{206}\)Pb/\({}^{207}\)Pb ratios ranging from 1.171 to 1.199, and for sediments near hunting areas (1.17-1.18, Table 1) [33]. When comparing these values with different natural or anthropogenic lead sources, these data suggest that lead ammunition is the primary source of lead in these soils (Figure 1). Although some samples can have a similar isotope ratio to industrial sources (Figure 1), the study zone is in a small town (around 20,000 inhabitants) without significant lead-related industries. However, the range of isotope ratios for collected shot pellets differed with \({}^{206}\)Pb/\({}^{207}\)Pb ratios of 1.1155, 1.1691 and 1.211, while \({}^{208}\)Pb/\({}^{206}\)Pb ratios were 2.1431, 2.1016 and 2.0309, respectively (Table 2). Interestingly, the one-shot pellet showed for the \({}^{206}\)Pb/\({}^{207}\)Pb ratio a value of 1.1691, and 2.1016 for \({}^{208}\)Pb/\({}^{206}\)Pb, a value very similar to the different soil samples, suggesting that it was primarily used in this installation (Figure 2b). This higher variability is expected in shooting ranges because shooting pellets can have different origins and manufacturers with Pb from various lead ores, as reviewed by [14; 24; 34; 35; 36] for lead ammunition, even with the use of recycled lead for shoot pellets, such as 'home-made' ammunition that could mask lead origin specificity [34; 35; 36; 37; 38]. As indicated by [36; 38], remanufacturing or reloading cartridges involves reusing previously fired cases and reloading these with the other components, including primers and propellants. As highlighted by [34], when various lead sources are recycled from a different product (e.g., mix of recycled batteries and other uses), the distinctive isotopic ratio may become progressively less characteristic, and therefore, the source determination can be more complex [19; 34; 36; 37]. When the shot pellets ratio was compared with other shot pellet manufacturers (Table 2, Figure 2), it suggested a potential European origin for the potentially most used pellet, with similar ratios as indicated by different authors for European manufacturers [5; 39; 40]. Additionally, it was interesting to see that one-shot pellets have a lead isotope rate very similar to American lead pellets, suggesting the use of American manufacturers (Figure 2a,b). However, this shooting range was abandoned several years ago, and we cannot know which ammunitions were mainly used to compare and verify our results. Figure 1: Scatter plot for \({}^{208}\)Pb/\({}^{206}\)Pb versus \({}^{206}\)Pb/\({}^{207}\)Pb of lead isotope ratios for different environmental components in the vicinity of the study area. Data from [27; 28; 29; 30; 31; 32]. \begin{table}
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