Non-Phthalate Ester Plasticizers in Airborne Fine Particles from Chinese Cities: Broad Distributions and Spatiotemporal Trends

In contrast with phthalate esters (PAEs), many non-PAE plasticizers (NPPs) remain poorly characterized in their environmental distribution. Our work explored the spatial distributions of 44 NPPs in airborne fine particles (PM_2.5) from 13 Chinese cities as well as the temporal change of contamination at a selected city (Jinan, Shandong Province). The results revealed ubiquitous distributions of several groups of NPPs in the ambient environment, such as oleates, adipates, citrates, and isobutyrates. The total abundance of NPPs (ΣNPPs) ranged from 0.37 to 54.7 ng/m³, and the ratios of ΣNPPs to ΣPAEs ranged from 0.06 to 4.17 across the study sites. The spatial variations in ΣNPPs appeared to be significantly associated with the gross domestic product of the cities, indicating a link between economic prosperity and environmental releases of NPPs. The ratios of ΣNPPs to ΣPAEs also exhibited a significant temporal increase during the period of 2015–2020 in the study site located in Jinan, providing strong evidence of the increasing applications of NPPs relative to PAEs in previous years. Our work constitutes one of the first reports on the spatiotemporal distributions of NPPs over a large geographic range.