Polycyclic Aromatic Hydrocarbons in Sediments/Soils of the Rapidly Urbanized Lower Reaches of the River Chaohu, China.

Wu Wu,Li Li,Sun Sun

doi:10.3390/ijerph16132302

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are highly teratogenic, persistent carcinogens, and ubiquitous environmental pollutants. To determine the impact of rapid urbanization on sediment/soil PAHs, we collected 30 cm soil cores in ditch wetlands, riverine wetlands, and agricultural lands along the lower reaches of the Shiwuli River feeding Chaohu Lake, China. Ecological risk effects were evaluated by two models based upon Benzo[a]pyrene toxic equivalency (TEQ-BaP) and total toxic units (TUs). The presence of PAHs, such as BbF, BkF, InP, and BgP, that are known pollutants of concern, suggests certain ecological risks. The concentration of PAHs in the surface layer followed in the order of: ditch wetlands (617.2 ng/g average), riverine wetlands (282.1 ng/g average), agricultural lands (103.7 ng/g average). PAHs in ditch sediments were vertically distributed evenly, and PAHs in agricultural soils were concentrated in the surface soil. In riverine wetland sediments, the 2-, 3-, and 4-ring PAHs had a uniform distribution, whereas the 5- and 6-ring PAHs were concentrated in the surface soil. Redundancy analysis (RDA) explored the correlation between the environmental properties and the occurrence of PAHs. Total organic carbon (p = 0.010), percent clay (p = 0.020), and distance (p = 0.020) were the primary factors in ditch wetlands. Depth (p = 0.010) and distance (p = 0.006) were the main factors in agricultural lands. There were no significant correlations in riverine wetlands. The correlation between the distance from the built-up urban areas and pollutant concentration showed that the closer the distance, the greater the concentration of PAHs.

Highlights

Polycyclic aromatic hydrocarbons (PAHs) are a group of ubiquitous persistent organic pollutants that are composed of two or more fused aromatic rings [1,2]
The results showed that the concentrations of PAHs measured in this study were lower than other wetlands in China, such as the Taihu Lake estuary, the Liaohe estuary, and the
According to the classification established by Maliszewska-Kordybach (Table 6) [35], all surface sediments in the ditch wetlands in this study were contaminated

Summary

Introduction

Polycyclic aromatic hydrocarbons (PAHs) are a group of ubiquitous persistent organic pollutants that are composed of two or more fused aromatic rings [1,2]. PAHs cause serious global environmental concerns for both ecosystems and human health because of their potential toxicity and carcinogenicity [3, 4]. Many phenomena come from urbanization, such as population aggregation, industrial development, increased construction of roads and vehicle use, and the construction of landfills [2]. Polycyclic Aromatic Hydrocarbons (PAHs) are a group of organic pollutants that are strongly related to anthropogenic activities such as settlement, transport, and industrial development [6,7]. The PAHs contamination to the environment is accelerating, which increases the potential harm to human health [8]. PAHs in urban areas can be emitted into urban rivers through multiple pathways, including wastewater discharge, atmospheric deposition, oil spillage, and surface run off [9]

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