Environmental tracers are substances or properties used to identify and track the movement of pollutants, contaminants, or other substances in the environment. These tracers can include natural substances such as isotopes, chemicals, or biological markers, as well as artificially introduced markers like dyes or radioactive isotopes. By analyzing the behavior of these tracers in the environment, researchers can gain insights into the transport, fate, and sources of contaminants in water, air, soil, and other environmental media. Environmental tracers are widely used in environmental science, hydrology, and environmental monitoring to study complex environmental processes and inform environmental management and remediation strategies.