Samples were collected from six ground-based sites located in Chengdu, a typical rapidly developing metropolitan area in Southwest China, and were analysed for seven OPEs in atmospheric PM_2.5 (Σ₇ OPEs). The concentrations of Σ₇ OPEs were higher in autumn and winter than in summer. In contrast to coastal cities, sustained and stable high local emissions in the inland city studied were identified, which is particularly noteworthy.