Climate-exacerbated mobilization of legacy heavy metals and other potentially toxic elements on human health risks in the Kyzylorda–Aral sea region

Abstract The Kyzylorda region of Kazakhstan is an example of climate-intensified aridification exacerbating the vulnerability of legacy environmental pollutants. The desiccation of the Aral Sea was primarily caused by the extensive diversion of the Syr Darya and Amu Darya rivers for irrigation. This narrative review synthesizes and contextualizes evidence on the major contaminant sources, climate-driven mobilization processes, human exposure pathways, and associated health outcomes in the region. The major anthropogenic inputs of heavy metals in the region include agricultural, industrial, and mining activities in the Syr Darya-Aral Sea system, with some contribution from naturally occurring geogenic sources. Climate-driven drying of water bodies and soils has increased pollutant concentrations, while enhanced mobilization via dust storms, surface water flow, and groundwater transport has expanded environmental dispersion. Human exposure occurs predominantly through the inhalation of contaminated dust and the consumption of contaminated water and food cultivated in affected soils. Regional observational studies suggest potential associations between environmental pollution and some adverse health outcomes, particularly in potentially vulnerable groups, but causal links to metals remain poorly established. The review also examines mitigation strategies and their potential application in the Kyzylorda region to reduce further climate-driven health impacts.