Insights into the Atmospheric Persistence, Transformation, and Health Implications of Organophosphate Esters in Urban Ambient Air

Abstract

Transformation of organophosphate esters (OPEs) in natural ambient air and potential health risks from coexposure to OPEs and their transformation products are largely unclear. Therefore, a novel framework combining field-based investigation, in silico prediction, and target and suspect screening was employed to understand atmospheric persistence and health impacts of OPEs. Alkyl-OPE transformation products ubiquitously occurred in urban ambient air. The transformation ratios of tris(2-butoxyethyl) phosphate were size-dependent, implying that transformation processes may be affected by particle size. Transformation products of chlorinated- and aryl-OPEs were not detected in atmospheric particles, and atmospheric dry deposition might significantly contribute to their removal. Although inhalation risk of coexposure to OPEs and transformation products in urban ambient air was low, health risks related to OPEs may be underestimated as constrained by the identification of plausible transformation products and their toxicity testing in vitro or in vivo at current stage. The present study highlights the significant impact of particle size on the atmospheric persistence of OPEs and suggests that health risk assessments should be conducted with concurrent consideration of both parental compounds and transformation products of OPEs, in view of the nonnegligible abundances of transformation products in the air and their potential toxicity in silico .

Anthropogenic Impacts on Organophosphate Ester Loads to an Urban Estuary in South China

“…Detailed gradient conditions are provided in our previous study. 29 The temperatures of the column and ion source were maintained at 40 and 550 °C, respectively. Measurement was performed using multiple-reaction monitoring in positive ion electrospray ionization under 4500 V spray voltage.…”

“…The mobile phases consisted of 50-mM formic acid in water (aqueous phase) and 10-mM ammonium acetate in methanol (organic phase), with a total flow rate of 200 μL min –1 . Detailed gradient conditions are provided in our previous study . The temperatures of the column and ion source were maintained at 40 and 550 °C, respectively.…”

Recent applications of mass spectrometry in the analysis of transformation products of emerging contaminants in PM2.5

“…59 According to the generated transformative structures and screening results obtained from the NTA of HR LC-MS/MS, a series of Cl-PFPECAs TPs and their congeners with different functional groups, that is, hydroxy-, vinyl-, expo-, and dihydroxy-substituted Cl-PFPECAs were tentatively observed as the proposed PFAS transformation schemes demonstrated (Figure 4B). The concentration of Cl-PFPECAs and identified TPs was further semi-quantified by normalizing their chromatography peak area ratios compared to the internal matrix standard (mass-labeled perfluorononanoic acid, 13 C 5 -PFNA). It is proposed that a chlorine-to-hydrogen substitution during reductive dehalogenation was a plausible transformation mechanism based on the observed similarities between these found congeners and Cl-PFESAs.…”

“…Mass spectrometry (MS), as a powerful analytical tool, has been widely applied in determining novel transformed pollutants in PM 2.5 11–15 . Different from the traditional techniques such as thin‐layer chromatography and gas/liquid chromatography (GC/LC) with unspecific detectors, MS techniques with high specificity can identify and elucidate the TPs with accurate molecular masses of both precursor compounds and fragments.…”

“…its precursor AO168 = O (52900 ng/g), implying an exceed human exposure through inhalation 35. Similarly, Lao et al have utilized the LC quadrupole TOF (qTOF) MS operated at DIA mode to suspect screening of the TPs of PM 2.5 -bonded OPEs in Hong Kong 13. The scanning pattern with dynamic background subtraction enables full scan and simultaneously triggers MS 2 data acquisition.…”