[Research Progress on the Impacts and Health Effects of Combined Contamination of Microplastics and Cadmium in Soils]

Microplastics are widespread in soils， and their potential ecological risks have attracted global attention. The interactions between microplastics and Cd in soil may pose new risks to ecosystem safety and human health. Bibliometric statistical results show that the research on microplastics and Cd combined pollution is one of the current research hotspots and is still in its infancy. This study systematically reviews the current research status of microplastics and Cd combined pollution worldwide and outlines the interactions between microplastics and Cd in soil and their effects on the bioavailability of Cd， as well as the ecological hazards and health effects. The results showed that the cadmium-based additives leached from microplastics and the adsorption/desorption of Cd by microplastics were the main factors influencing the distribution and bioavailability of Cd ions in soil. The impacts were determined by the structure and properties of the microplastics （such as type， particle size， and aging process）， the physicochemical properties of soil （such as pH， temperature， and conductivity）， and the duration and dose of exposure. In general， microplastics could affect Cd accumulation in organisms， change the toxic effects of Cd， and lead to more harmful effects on ecosystem safety and human health. This study highlights the necessity of further research on the combined pollution of microplastics and Cd， emphasizing the need to ① investigate the dynamic equilibrium mechanisms in their interactions； ② systematically examine the ecological and health effects under multifactorial conditions； and ③ explore the ecological impacts， health risks， and underlying mechanisms in natural environments. These studies will provide important references for the ecological risk assessment and management of microplastics and heavy metal combined pollution in agricultural soils.