Ecological and health risk assessments of polycyclic aromatic hydrocarbons (PAHs) in soils around a petroleum refining plant in China: A quantitative method based on the improved hybrid model

Polycyclic aromatic hydrocarbons (PAHs) are extensively released into the environment by petroleum refining activities, predominantly affecting soil as a major reservoir. This study focuses on an active petroleum refinery in central China and employs a multi-faceted approach, combining geo-statistics, the absolute principal component-multiple linear regression model, and the Monte Carlo simulation, to comprehensively unravel the sources and risks associated with 12 PAHs. The analysis reveals a wide range of PAH concentrations, spanning from 60.23 to 1678.00 μg·kg-1, with an average of 278.91 μg·kg-1. Strikingly elevated PAH levels are primarily concentrated in construction and transportation lands, whereas woodland and grasslands exhibit lower PAH concentrations. In terms of ecological impact, the risk arising from oil-coal combustion significantly surpasses that linked to biomass combustion. meticulous assessments indicate negligible carcinogenic risks for both children and adults within the study area. An innovative hybrid model, which seamlessly integrates risk assessments with source identification, emerges as a pivotal advancement. This hybrid model not only quantifies PAH emission levels from refining activities but also effectively quantifies potential risks from distinct sources. Consequently, this study furnishes a robust theoretical foundation for strategizing PAH pollution risk mitigation. In essence, our research not only contributes a comprehensive understanding of PAH distribution around an active petroleum refinery but also introduces an advanced hybrid model, culminating in valuable insights for devising measures to curtail PAH-related environmental risks.