Abstract

This overview presents the updated physicochemical characteristics of thallium and its stable isotopes (²⁰⁵Tl/²⁰³Tl) in the context of their occurrence and fate in abiotic and biotic systems. This also deals with the thallium behavior in geochemical interactions in and between different environmental compartments and describes its natural (geogenic) and industrial sources. The particular emphasis is placed on some extreme environments, including acid mine drainage areas where oxidation processes of Tl-bearing pyrite and other sulfides lead to very high concentrations of this metal in reactive acidic waters. Many geochemical studies have also employed stable thallium isotopes to reconstruct redox conditions in different environmental systems, to fingerprint relative pollution source strengths and to evaluate mobility of this element and its geochemical interactions in the mineral-water and soil–plant systems. This is the reason why this overview also highlights the growing potential of stable Tl isotopes in solving different geologic and environmental issues.

Graphic abstract