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E-Journal Bonus Article: Pollution Characteristics and Potential Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons in Wastewater Irrigated Soil

Abstract

Soil contamination by polycyclic aromatic hydrocarbons (PAHs) is an increasing problem. We wanted to determine the characteristics and ecological risk of PAHs in wastewater-irrigated soil, provide a theoretical basis for the prevention of PAH contamination in soils, and inform the formulation of guidelines and standards for critical limits of PAHs. We collected soil samples from two typical wastewater-irrigated farmlands, Farmlands A and B, in Tangshan, China, and used a clean-water irrigated farmland, Farmland C, as the control area. A total of 15 samples were analyzed for 16 PAHs by high-performance liquid chromatography. The results showed that the total amount of PAHs in samples from Farmlands A and B were 1046.2 μg/kg and 1308.1 μg/kg, respectively—significantly higher than Farmland C’s 189.1 μg/kg. The PAHs from wastewater-irrigated soil mainly consisted of PAHs of 4-rings or higher, accounting for 83.1% and 60.2% of total PAHs for Farmlands A and B, respectively. The evaluation of the ecological risk of PAHs using the single-factor index method and Nemerow comprehensive index (Pn) method revealed the main PAHs exceeding the critical limits were pyrene, dibenz[a,h]anthracene, and benzo[g,h,i]perylene. The Pn for the two wastewater-irrigated soils were 3.05 and 3.16, respectively, for Farmlands A and B, reaching a heavy pollution level versus Farmland C’s 0.34, classified as a clean level. We conclude that wastewater irrigation has led to ecological risk, and the wastewater-irrigated soil is carcinogenic, teratogenic, and mutagenic.

Speaker / Author: 
Hongxia Gao, Hebei Province Key Laboratory of Occupational Health & Safety, School of Public Health, North China University of Science & Technology
Yingli Liu, Hebei Province Key Laboratory of Occupational Health & Safety, School of Public Health, North China University of Science & Technology
Weijun Guan, Hebei Province Key Laboratory of Occupational Health & Safety, School of Public Health, North China University of Science & Technology
Nan Liu, Hebei Province Key Laboratory of Occupational Health & Safety, School of Public Health, North China University of Science & Technology
Shoufang Jiang, Hebei Province Key Laboratory of Occupational Health & Safety, School of Public Health, North China University of Science & Technology
Month Year: 
May 2017
Volume#: 
79.9
Page #: 
E1-E6
Publication Month: 
May 2017