Bioaccessibility-integrated probabilistic risk assessment for poly-aromatic hydrocarbons in Chinese soils

Area of Science:

• Environmental Chemistry
• Risk Assessment
• Soil Science

Background:

• Polycyclic Aromatic Hydrocarbons (PAHs) pose significant environmental and health risks.
• Traditional risk assessments based on total PAH concentration may overestimate actual health impacts.
• Integrating bioaccessibility data offers a more refined approach to evaluating PAH risks in soils.

Purpose of the Study:

• To establish a probabilistic risk assessment framework for PAHs in Chinese soils.
• To integrate bioaccessibility data and regional concentration variability for improved health risk evaluations.
• To characterize PAH contamination patterns and assess risks across different land use types and regions in China.

Main Methods:

• Systematic literature review of 697 general land use sites and 245 industrially contaminated sites.
• Characterization of PAH contamination patterns and bioaccessibility across diverse land use and regional settings.
• Development of a probabilistic risk assessment framework using ArcGIS-based kriging interpolation and Monte Carlo simulations.

Main Results:

• General land use soils exhibited a north-south contamination gradient, while industrial sites showed severe contamination in northern and southeastern coastal regions.
• Carcinogenic PAHs showed significantly lower bioaccessibility (median <35%), reducing estimated health risks by approximately 50%.
• Industrial sites posed substantially higher risks (mean 1.73 × 10⁻⁵) than general land use sites (below 1 × 10⁻⁶), particularly in North China.

Conclusions:

• Bioaccessibility-integrated, region-specific, and land use-differentiated management strategies are essential for effective PAH risk mitigation.
• BaP and DahA are identified as primary drivers of carcinogenic risk.
• Soil PAH concentration, bioaccessibility, and child exposure duration are key factors influencing risk uncertainty.