Composition of fine particulate matter and risk of preterm birth: A nationwide birth cohort study in 336 Chinese cities

Yuan He, Yixuan Jiang, Ying Yang, Jihong Xu, Ya Zhang, Qiaomei Wang, Haiping Shen, Yiping Zhang, Donghai Yan, Zuoqi Peng, Cong Liu, Weidong Wang, Tamara Schikowski, Huichu Li, Beizhan Yan, John S. Ji, Aimin Chen, Aaron van Donkelaar, Randall V. Martin, Renjie Chen, Haidong Kan, Jing Cai, Xu Ma