Beyond single scenarios: multi-scenario analysis of PAH exposure and health risks in China

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants widely distributed in the environment and linked to adverse health effects. Yet integrated assessments across multiple media, exposure pathways, and environmental scenarios remain limited. Here, we applied a multi-media, multi-pathway framework to estimate population exposure to PAHs and associated carcinogenic risks in China. PAH concentrations in air, water, soil, dust, and food were compiled from studies published between 2010 and 2024. Average daily doses (ADDs) were calculated for dietary intake, inhalation, oral ingestion, and dermal contact pathways, while carcinogenic risks were quantified using benzo[a]pyrene equivalents (BaP_eq) and incremental lifetime cancer risk (ILCR). PAH levels differed markedly by medium and scenario: industrial areas showed higher concentrations in air and water, while urban areas were characterized by elevated dust and soil burdens; rural areas were generally lower. In the primary assessment, dietary intake contributed substantially to both total PAH exposure and carcinogenic risk. A percentile-based dietary scenario analysis showed that the industrial-urban-rural risk ranking remained stable within each age group, although absolute total ILCR values and some age-group comparisons were sensitive to dietary-pathway uncertainty. Monte Carlo and sensitivity analyses further indicated that pathway-specific ILCR variability was most strongly associated with medium-specific BaPeq concentrations.