Levels, Sources and Toxicity Risks of Polycyclic Aromatic Hydrocarbons at an Island Site in the Gulf of Tonkin.

Xiaoyang Yang,Zhaoyu Mo,Jingying Mao,Yu Liu,Wenjuan Zhao,Shijie Liu,Yuanguan Gao

doi:10.3390/ijerph17041338

Abstract

The varying concentrations of polycyclic aromatic hydrocarbons (PAHs) at remote islands is an important indicator, demonstrating the contributions from different regional combustion sources. In this study, gaseous and particulate PAHs were measured at Weizhou Island in the Gulf of Tonkin from 15th March to 14th April, 2015. The concentrations of PAHs ranged from 116.22 to 186.74 ng/m3 and from 40.19 to 61.86 ng/m3 in gas and particulate phase, respectively, which were much higher than those of some remote sites in Asia. Phenanthrene, fluoranthene, pyrene, and chrysene, which were mainly found in diesel vehicle emissions, had relatively high concentrations in both gas and particulate phases. According to the comprehensive results of back trajectory cluster analysis and diagnostic ratios, the local vessel emission was probably the main source of PAHs, which was much more important than the coal and biomass combustion sources from remoter regions. The toxicities represented by ∑PAH7, benzo(a)pyrene-equivalent carcinogenic power, and 2,3,7,8-tetrachlorodibenzo-p-dioxin-based total toxicity potency are much higher in particulate phase than those in gas phase. However, the toxicities of gas phase should not be neglected from the point of view of indirect-acting mutagenicities due to the high contribution of fluoranthene.

Highlights

Much attention is being paid to the presence of polycyclic aromatic hydrocarbons (PAHs), which are carcinogenic and/or mutagenic chemicals, in the environment [1,2]
The toxicities of gas phase should not be neglected from the point of view of indirect-acting mutagenicities due to the high contribution of fluoranthene
The toxicity risk of PAHs was analyzed using the indexes of PAH7, BaP-equivalent carcinogenic power (BaPE), TEQ and indirect-acting mutagenicities (IDMs)

Summary

Introduction

Much attention is being paid to the presence of polycyclic aromatic hydrocarbons (PAHs), which are carcinogenic and/or mutagenic chemicals, in the environment [1,2]. PAHs in the atmosphere mainly originate from the incomplete combustion of fossil fuels and biomass, such as motor-vehicle emission, heating supply, energy production and crop residue burning [3,4,5,6,7]. PAHs have been found in both the particulate and gaseous phases of combustion emissions and the ambient atmosphere due to their semi-volatile characteristics [8,9,10]. Gas-particle partitioning is an important factor influencing the fate of PAHs in the environment, such as long-range atmospheric transport, transformation between phases, and removal from the atmosphere via wet and dry deposition [11,12]. Economic activity has a close connection to the emission of pollutants, and a lot of

Methods

Results

Conclusion