Association between urine metal exposure and sleep quality among Zhuang ethnic postmenopausal women in China - Peini Lu; Dan Luo; Lidi Lei; Yingrong Chen; Xuemei Xu; Gangjie Wei; Xuanqian Huang; Dongping Huang; Li Su; Xiaoqiang Qiu; Xiaoyun Zeng; Shun Liu (Journal of Trace Elements in Medicine and Biology, 2026)