Development of copper contamination trajectory on the soil systems: A review on the application for stable copper isotopes

Soil copper (Cu) contamination is a ubiquitous and prevalent environmental problem in many countries (such as developed Cu-related industrial areas), endangering food safety and human health. Emerging as a crucial instrument, stable Cu isotope analysis is employed to differentiate between natural and human-induced sources of Cu and to employed the fate of Cu on the soil systems. This study provides an overview of: (i) the analytical methods for stable Cu isotopes, (ii) the Cu isotope compositions of possible end-members of Earth’s surface systems, including particulate matter and, dry and wet deposition to the soil, and (iii) the fractionation mechanisms of Cu isotopes in different types of pollutants, as a tracer for the origin of Cu in soils. These Cu isotope signatures have significant implications for the assessment and remediation of soil Cu pollution scenarios. However, the utilization of Cu isotope signatures remains limited to tracing the source of Cu-contaminated soils through Cu isotope analysis. As a result, this study also presents a perspective on the application of Cu isotopes to trace Cu sources and their fate in the soil.