Distribution, Sources and Risk Assessment of Polychlorinated Biphenyls in Soils from the Midway Atoll, North Pacific Ocean

Jing Ge,Lee Ann Woodward,Qing X Li,Jun Wang,Joseph J Barchi

doi:10.1371/journal.pone.0071521

Abstract

Concentrations of 28 polychlorinated biphenyls (PCBs) were assessed in soils from the Midway Atoll in the central North Pacific Ocean. The analytical procedure involved the application of accelerated solvent extraction (ASE) and gas chromatography coupled with ion trap mass spectrometric detection (GC/ITMS) for identification and quantification. Among the 28 PCB congeners studied, 26 of them, except CB195 and CB209, were detected in the analyzed samples at different frequencies. The total concentrations of 28 indicator PCBs (ΣPCBs) ranged from 2.6 to 148.8 ng g−1 with an average value of 50.7 ng g−1 and median of 39.5 ng g−1. Sources and congeners’ pattern of PCB were investigated in the soil of Midway Atoll. The principal component analysis indicated that the compositions of PCBs in most of the soil samples were similar. The total concentrations of PCBs were used to assess the cancer risk probabilities in humans via ingestion, dermal contact and inhalation of soil particles. Very low cancer risk was found in all soil samples caused by ΣPCBs.

Highlights

Persistent organic pollutants (POPs), as polychlorinated biphenyls (PCBs) and OCPs are synthetic compounds with great chemical stability
PCBs are believed to act as endocrine disruptors that affect hormone regulation [5]
Significant correlations between biochemical parameters and residues of endocrine disrupting chemicals were found in some marine animal species, which indicates that these chemicals may impose toxic effects in animals even at the current levels of exposure

Summary

Introduction

Persistent organic pollutants (POPs), as PCBs and OCPs are synthetic compounds with great chemical stability. Due to the wide use throughout the world since the middle of the past century, these compounds are ubiquitous in the environment and pose an environmental and human risk [1,2]. Some of these pollutants are highly toxic and have a large variety of chronic effects, including endocrine dysfunction, mutagenesis and carcinogenesis. Significant correlations between biochemical parameters (serum hormone concentrations and cytochrome P450 enzyme activities) and residues of endocrine disrupting chemicals were found in some marine animal species, which indicates that these chemicals may impose toxic effects in animals even at the current levels of exposure. Water birds and marine mammals accumulated the dioxin-like compounds with much higher concentrations than humans, implying higher risk from exposure in wildlife [6]

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