Space-time characteristics of 16 PM_₂.₅-bound phthalates (PAEs) in ambient air from Shanghai: Profiles, sources, meteorological effects, and exposure risks

Generated by chemical combinations between alcohols and phthalic anhydrites, phthalates are a group of synthetic chemicals broadly utilized as plasticizers. They occur in both particle and gas phases in the air causing threats to human health. In the study in hands, LC-MS/MS was employed for the analysis of PM₂.₅-PAEs in 128ambient PM₂.₅ samples from nine locations (urban, sub-urban and coastal) in Shanghai between February 2015 and September 2021. Six PAE congeners, namely di-n-butylphthalate(DBP), dimethylphthalate (DMP), diisononylphthalate (DINP), di-2-ethylphthalate(DEP), diisobutyl phthalate (DIBP) and di (2-propylheptyl) phthalate (DPHP),which are grouped as (∑6PAEs) were the most profuse species (with detection frequency (DF) ranging from 44.5% to 85.9%), with concentrations ranging between 26.85 (DEP) to 1840 ng m⁻³ (DIBP). Two congeners (DBP and DIBP) contributed significantly (79.4%) to the overall concentration of PAEs in the campaign, and exhibited a strong positive correlation (Spearman: r = 0.876,p < 0.05). Densely populated sites and those situated in periphery of manufacturing areas seemed to exhibit higher mean concentrations of ∑6PAEs.Daily mean and median concentrations comprising all the species (∑16PAEs) were generally higher in samples collected during colder periods (38.3 and 37.5 ng m⁻³,respectively) rather than within samples gathered in warmer periods (31 and26.9 ng m⁻³, respectively), though there wasn't a statistically significant difference between mean concentrations for both periods (ANOVA: p> 0.05, F stat. < F critical). Statistically significant correlations were found between temperature and concentrations of both DBP and ∑16PAEs (p< 0.05, r = 0.34 and 0.35, respectively). Among population groups, an elevated daily intake (EDI) ranging from 1.04 to 27.95 ng kgBWt^⁻¹ day^⁻¹ was found for toddlers, with the highest estimated hazard index of 1.5 × 10⁻². Copyright © 2023 The Author(s).