Distribution, source diagnostics, and factors influencing polycyclic aromatic hydrocarbons in the Yellow River Delta wetland

Investigating polycyclic aromatic hydrocarbons (PAHs) in estuarine wetlands is crucial for protecting the ecological environment. In this study, we examined the distribution of PAHs in surface soil samples from the Yellow River Delta (YRD) wetland and identified their sources, pollution status, and influencing factors. The results indicate that the PAH concentrations in the YRD samples ranged from 14.1 to 47.1 ng/g (mean = 28.3 ng/g). Application of the isomeric ratios, principal component analysis, and the positive matrix factorization model indicated that the primary PAH pollution sources in the surface soil were oil pollution, vehicle emissions, and coal and biomass combustion. The distribution of PAHs in the surface soil was affected by vegetation type, pH, soil organic matter, soil water content, and soil grain size. Overall, the YRD exhibited a low pollution level, although continued monitoring is necessary to reduce the environmental impact of PAHs.