Combined pollution from microplastics (MPs) and other environmental pollutants has attracted considerable attention. Few studies have investigated the effects of polyurethane (PU) and polypropylene (PP) MPs on available Cadmium(Cd) in different soil types. Here, PU and PP additions affected available Cd and reduced its concentration in soil (P > 0.05). PU and PP reduced available Cd more strongly in clay soil than that in sandy soil. PU and PP improved the soil porous structure and voids and significantly increased the Zeta potential in clay soil (P < 0.05). Dissolved organic carbon and pH in clay soil were significantly negatively correlated with available Cd after PU and PP addition, and Fe(Ⅱ) was significantly negatively correlated with available Cd in sandy soil. PU and PP addition promoted the C-C, CO₃^2-, and C-H functional groups and FeO, FeOOH, and Fe₃O₄ formation and influenced the effective Cd through adsorption and precipitation. CdCO₃ formation and clay mineral adsorption, and iron oxide formation, influenced the effective Cd in clay and sandy soils, respectively. PU and PP influenced the effective state of Cd by affecting bacterial communities related to carbon and iron cycles. This study is significant for assessing the environmental risks of MPs combined with heavy metals in different soils and their mechanisms.

微塑料（MPs）和其他环境污染物的联合污染引起了相当大的关注。很少有研究调查聚氨酯 (PU) 和聚丙烯 (PP) MPs 对不同土壤类型中有效镉 (Cd) 的影响。此处，添加 PU 和 PP 会影响有效 Cd 并降低其在土壤中的浓度（P > 0.05）。PU和PP在粘土中比在沙土中更强烈地减少有效Cd。PU和PP改善了土壤的多孔结构和孔隙，显着提高了粘土中的Zeta电位（P < 0.05）。添加PU和PP后黏土溶解有机碳和pH与速效Cd呈显着负相关，沙质土壤Fe(Ⅱ)与速效Cd呈显着负相关。PU和PP的添加促进了CC、CO ₃ ^2-, 和 CH 官能团和 FeO、FeOOH 和 Fe ₃ O ₄的形成并通过吸附和沉淀影响有效 Cd。CdCO ₃的形成和粘土矿物的吸附以及氧化铁的形成分别影响粘土和沙质土壤中的有效 Cd。PU和PP通过影响与碳和铁循环相关的细菌群落来影响Cd的有效状态。本研究对评估不同土壤中MPs与重金属的环境风险及其作用机制具有重要意义。