Assessment of Radioactive Lead Isotopes in the Environment of Kazakhstan

Abstract

The industry of Kazakhstan, including the combustion of high-ash coal, uranium mining and processing, non-ferrous metallurgy, oil production, and the consequences of nuclear weapons testing, creates a unique environment for the occurrence of radioactive lead isotopes. Unlike stable lead isotopes commonly used for source apportionment of pollution, the radioactive isotopes ²¹⁰Pb (T_1/2 = 22.3 years), ²¹²Pb (T_1/2 = 10.6 hours), and ²¹⁴Pb (T_1/2 = 26.8 minutes) are directly associated with the release of radon (²²²Rn) and thoron (²²⁰Rn), as well as aerosol dynamics, making them excellent indicators of both natural and technologically enhanced radiation exposure. This study represents the first attempt to assess the comprehensive distribution of radioactive lead isotopes in atmospheric aerosols, soils, and waters of Kazakhstan and their contribution to the global environment.

The study identified several major gaps requiring further investigation: (1) the absence of a nationwide spatial inventory of ²¹⁰Pb in air and soil; (2) the lack of any measurements of ²¹²Pb and ²¹⁴Pb near coal-fired power plants and uranium tailings; and (3) the unknown chemical forms (bioavailability) of ²¹⁰Pb in emission plumes. Specific recommendations are proposed to address each of these gaps.