Inhalation bioacessibility and lung cell penetration of indoor PM2.5-bound PAEs and its implication in risk assessment

Severai studies have evalitateu ihe human expostue of phthalate esters (PAEs) in PM2.5 via inhalation route, however, inhalation bioaccessibility and the hm,: .center dot ell penetration of PAEs were barely considered in risk assessment. In the present study, PM2.5 samples collected from indoor environments were investigated for inhalation oioaccessioility of PAEs ming two simulated lung (luids (gannle's solution (GMB) and artificial lysosomal fluid (ALF)). The results showed that the inhalation bioaccessibility of PAEs (except for diethyl phthalate) under healthy state (GMB: 8.9%-62.8%) was lower than that under the inflammatory condition (ALF: 14.5%-67.6%). Lung cell perrneation and metabolism of three selected PAEs (diethyl phthalate, di(n-butyl) phthalate and di-2-ethylhexyl phthalate) was tested using equivalent lung cell (A549) model. The inhalation bioavailability obtained by combination of the bioaccessibility of PAEs in indoor PM2,; and permeability data of A549 cell ranged from 11.7% to 51.1% in health condition, and 13.5%-55.0% in inflammatory state. The calibration parameter (Fc) based on the inhalation bioavailability was established in present study and could provide a reference for a more accurate risk assessment of PM2.5-bound PAEs.

Automated summary

Several studies have evaluated the inhalation exposure of phthalate esters (PAEs) in PM2.5, but have not considered inhalation bioaccessibility and lung penetration of PAEs in risk assessment. This study investigated the inhalation bioaccessibility of PAEs in indoor PM2.5 samples using simulated lung fluids, and tested the lung cell permeation and metabolism of selected PAEs using a lung cell model. The results showed that the inhalation bioavailability of PAEs varied depending on the health condition and the presence of inflammation.