Source Analysis and Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Paddy Soils

ABSTRACT

Polycyclic aromatic hydrocarbons (PAHs) are typically persistent organic pollutants with hypertoxicity and widespreading, attracting increasing attention in recent years. Six paddy land sites soils irrigated from different rivers in the Nansi Lake area of Shandong Province, China, were studied to analyze and assess the source and risk of PAHs.Analysis revealed total PAHs (TPAHs) concentrations in topsoil ranging from 57.49 to 2046.47 μg kg⁻¹, meanwhile, Weishan County (WS) was highly contaminated primarily from coal combustion based on the Nemerow composite index and geochemical indices.Canonical correspondence analysis (CCA) suggested that bacterial species were affected by pH, TPAHs, and soil organic matter (SOM), while covariables analysis confirmed that most effects of PAHs on bacterial diversity were attributed to the PAHs effect alone rather than the combined effects of PAHs and soil properties. The average daily human exposure (ADE) in children was approximately 2 times higher than that in adults, and the exposure paths values followed a decreasing order, oral intake > skin contact > inhalation. Furthermore, the WS site and another rice test field (TF) presented potential cancer risks and required further investigation. Therefore, the study has important theoretical significance for the control of PAHs pollution in this field, providing a scientific basis for health assessment.

KEYWORDS:

• PAHs
• paddy soil
• bacterial species
• source analysis and risk assessment
• statistical analysis and model
• Nansi Lake

Funding

This research was supported by the Key Industry Key Technology Innovation Project of Shandong Province (No. 2016CYJS05A02), the China Postdoctoral Science Foundation (No. 2015M572016), the Fundamental Research Funds of Shandong University (No. 2014JC048), and the National Natural Science Foundation of China (No. 41201318).