Crop-Type-Specific Polycyclic Aromatic Hydrocarbon Pollution in Field Soils Across Mainland China: Dietary Health Risks, Driving Factors, and Associations with Plastic-Related Contaminants

Crop field soils are a major reservoir for polycyclic aromatic hydrocarbons (PAHs), yet how crop type influences PAH accumulation and dietary health risks remain unclear at the national scale, as does the role of agronomic and environmental drivers. This study collected 322 soil samples from crop fields covering over 30 crop species across 31 administrative divisions in mainland China. PAH concentrations differed significantly among the four major crop categories and the 13 subcategories (p < 0.05). However, dietary PAH exposure through cash crop fields posed the highest risk to adults (total: 1.1 × 10−4, unacceptable cancer risk), while food crop fields showed the lowest risk. Children faced a total dietary health risk of 6.0 × 10−5 (potential cancer risk), with vegetable and fruit fields contributing the highest risks. Agronomic practices (tillage frequency, irrigation method, agricultural film removal method), soil properties (total organic carbon, pH, total nitrogen), meteorological conditions (sunshine duration, shortwave radiation, precipitation), and altitude all significantly influenced soil PAH concentrations (p < 0.05). PAH concentrations were positively correlated with plastic-related contaminants (microplastics, phthalic acid esters, and organophosphate esters, p < 0.05). These findings provide scientific evidence for differentiated crop management and safe agricultural production.