Microplastics in stools and their influencing factors among young adults from three cities in China: A multicenter cross-sectional study - Yongye Song; Jianfen Zhang; Xiuhua Shen; Lina Yang; Yong Jia; Fangfang Song; Yue Huang; Bingyue Han; Shuyi Zhou; Na Zhang; Guansheng Ma (Environmental Pollution, 2025)