Haze episodes elevate PM_2.5-bound PAH and BFR loads without increasing bioaccessibility: Toward improved inhalation...

Area of Science:

• Environmental Science
• Toxicology
• Public Health

Background:

• Particulate Matter (PM2.5) carries harmful pollutants like Polycyclic Aromatic Hydrocarbons (PAHs) and Brominated Flame Retardants (BFRs).
• Accurate health risk assessment requires understanding the bioaccessibility of these inhaled pollutants.

Purpose of the Study:

• To investigate the concentration, bioaccessibility, and inhalation risks of PM2.5-bound PAHs and BFRs during haze and normal periods.
• To compare health risks estimated using total concentrations versus bioaccessibility-adjusted values.

Main Methods:

• Systematic investigation of PM2.5-bound PAHs and BFRs in northern China during haze and normal periods.
• Assessment of bioaccessibility using artificial lysosomal fluid (ALF) and Gamble's solution (GS) models.
• Calculation of inhalation risks based on total concentrations and bioaccessibility-adjusted values.

Main Results:

• Haze episodes showed significantly higher concentrations of PAHs (1.57 times) and BFRs (1.69 times).
• Bioaccessibility of PAHs and BFRs did not differ significantly between haze and normal periods.
• Total concentration-based risks overestimated health hazards by 5.71-20.6 times compared to bioaccessibility-adjusted risks.

Conclusions:

• Inhalation bioaccessibility is crucial for accurate health risk assessment of PM2.5-bound PAHs and BFRs.
• Standard risk assessments may overestimate hazards due to ignoring bioaccessibility.
• All assessed risks remained below established safety thresholds.