Fulvic acid-mediated oxidative stress and neurotoxicity in earthworms exposed to agricultural film-derived polyethylene microplastics: multifactorial regulation and biomarker dynamics - Yuicui NING; Zhipeng CHEN; Shou WANG; Yazhou YANG; Zihan XU; Hanyue CAO; Shoujun YANG; Bohang LI; Dongxing ZHOU (Pedosphere, 2026)