Sediment quality assessment combining chemical and biological (non)target analysis

Youmi Choi; Moonkoo Kim; Sung Yong Ha; Gi Myung Han; Un Hyuk Yim; Jee-Hyun Jung

doi:10.1016/j.aquatox.2021.105883

Sediment quality assessment combining chemical and biological (non)target analysis

Aquat Toxicol. 2021 Jun 8:238:105883. doi: 10.1016/j.aquatox.2021.105883. Online ahead of print.

Authors

Youmi Choi¹, Moonkoo Kim¹, Sung Yong Ha², Gi Myung Han², Un Hyuk Yim¹, Jee-Hyun Jung³

Affiliations

¹ Risk Assessment Research Center, Korea Institute of Ocean Science and Technology, Geoje 53201, Republic of Korea; Department of Ocean Science, Korea University of Science and Technology, Daejeon 34113, Republic of Korea.
² Risk Assessment Research Center, Korea Institute of Ocean Science and Technology, Geoje 53201, Republic of Korea.
³ Risk Assessment Research Center, Korea Institute of Ocean Science and Technology, Geoje 53201, Republic of Korea; Department of Ocean Science, Korea University of Science and Technology, Daejeon 34113, Republic of Korea. Electronic address: jungjh@kiost.ac.kr.

PMID: 34311228
DOI: 10.1016/j.aquatox.2021.105883

Abstract

Aquatic sediments act as a storage for diverse mixtures of organic and inorganic contaminants. Nevertheless, most evaluations of contaminated sediments have been limited to the assessment of concentrations of target compounds and lethal effects on some test species. To identify the organic contaminants causing sub-lethal effects of contaminated sediment, this study combined chemical and biological (non)target analysis involving comprehensive two-dimensional gas chromatography coupled with a time-of-flight Mass Spectrometer (GCxGC/ToF-MS) analysis, embryonic malformation and high-throughput sequencing (RNA-seq) analysis on developing flounder. Polycyclic aromatic hydrocarbons were more abundant in the sediment extract of Yeongil Bay (SEY), while Jinhae Bay (SEJ) was contaminated with a large amount of unidentified chemicals. The unidentified chemicals of SEJ included branched alkanes, oxygenated cycloalkanes, heterogeneous hydrocarbons, and other unknown compounds. Percentage of pericardial edema was the highest in embryonic flounder exposed to SEY. Consistent with the morphogenesis results, the expression level of genes related to heart formation including the nkx2.5 and robo1 was greater in embryonic flounder exposed to SEY. In the analyses of differential gene expression profiles (cutoff P < 0.05), by RNA-seq, embryos exposed to SEJ showed changes related to cell differentiation, cell part morphogenesis, neurogenesis, and neuron development. Genes related to neurogenesis and positive regulation of molecular functions variated significantly in embryos exposed to SEY. These results demonstrated the advantages of combining target and non-target analysis to accurately evaluate the major chemical groups causing sediment toxicity. Therefore, this work provided a useful approach to tracking and revealing the causes of toxic effects and identifying potential toxic mechanisms.

Keywords: GCxGC/ToF-MS; NGS; Non-target screening; Sediment; Toxicity.