Higher ecological risks and lower bioremediation potentials identified for emerging OPEs than legacy PCBs in the Beibu Gulf, China

Li Zhang; Lingfang Ni; Heng Wang; Zhichao Zhang; Yichun Wu; Renming Jia; Junyu He; Zuhao Zhu; Haiyan Jin; Xing Ren; Dongdong Zhang

doi:10.1016/j.envres.2023.116244

Higher ecological risks and lower bioremediation potentials identified for emerging OPEs than legacy PCBs in the Beibu Gulf, China

Environ Res. 2023 Aug 15;231(Pt 3):116244. doi: 10.1016/j.envres.2023.116244. Epub 2023 May 26.

Authors

Li Zhang¹, Lingfang Ni², Heng Wang³, Zhichao Zhang³, Yichun Wu⁴, Renming Jia¹, Junyu He⁵, Zuhao Zhu¹, Haiyan Jin⁶, Xing Ren¹, Dongdong Zhang⁷

Affiliations

¹ Guangxi Key Laboratory of Beibu Gulf Marine Resources, Environment and Sustainable Development, Fourth Institute of Oceanography, MNR, Beihai, 536000, PR China.
² Key Laboratory of Ocean Space Resource Management Technology, And Key Laboratory of Marine Ecosystem Dynamics, MNR, Hangzhou, 310012, PR China; Institute of Marine Biology and Pharmacology, Ocean College, Zhejiang University, Zhoushan, 316021, PR China.
³ Zhoushan Municipal Center for Disease Control and Prevention, Zhoushan, 316021, PR China.
⁴ Zhoushan Institute for Food and Drug Control, Zhoushan, 316012, PR China.
⁵ Institute of Marine Biology and Pharmacology, Ocean College, Zhejiang University, Zhoushan, 316021, PR China.
⁶ Key Laboratory of Ocean Space Resource Management Technology, And Key Laboratory of Marine Ecosystem Dynamics, MNR, Hangzhou, 310012, PR China.
⁷ Guangxi Key Laboratory of Beibu Gulf Marine Resources, Environment and Sustainable Development, Fourth Institute of Oceanography, MNR, Beihai, 536000, PR China; Key Laboratory of Ocean Space Resource Management Technology, And Key Laboratory of Marine Ecosystem Dynamics, MNR, Hangzhou, 310012, PR China; Institute of Marine Biology and Pharmacology, Ocean College, Zhejiang University, Zhoushan, 316021, PR China. Electronic address: zhangdongzju@zju.edu.cn.

PMID: 37245567
DOI: 10.1016/j.envres.2023.116244

Abstract

The production and use of organophosphate esters (OPEs) as substitutes for traditional halogenated flame retardants is increasing, resulting in greater global concern related to their ecological risks to marine environments. In this study, polychlorinated biphenyls (PCBs) and OPEs, representing traditional halogenated and emerging flame retardants, respectively, were studied in multiple environmental matrices in the Beibu Gulf, a typical semi-closed bay in the South China Sea. We investigated the differences in PCB and OPE distributions, sources, risks, and bioremediation potentials. Overall, the concentrations of emerging OPEs were much higher than those of PCBs in both seawater and sediment samples. Sediment samples from the inner bay and bay mouth areas (L sites) accumulated more PCBs, with penta- and hexa-CBs as major homologs. Chlorinated OPEs were prevalent in both seawater and sediment samples from the L sites, whereas tri-phenyl phosphate (TPHP) and tri-n-butyl phosphate (TNBP) were predominant at the outer bay (B sites) sediment samples. Source identification via principal component analysis, land use regression statistics, and δ¹³C analysis indicate that PCBs were mainly sourced from the atmospheric deposition of sugarcane and waste incineration, whereas sewage inputs, aquaculture, and shipping activity were identified as sources of OPE pollution in the Beibu Gulf. A half-year sediment anaerobic culturing experiment was performed for PCBs and OPEs, and the results only exhibited satisfactory dechlorination for PCBs. However, compared with the low ecological risks of PCBs to marine organisms, OPEs (particularly trichloroethyl phosphate (TCEP) and TPHP) exhibited low to medium threats to algae and crustaceans at most sites. Given their increasing usage, high ecological risks, and low bioremediation potential in enrichment cultures, pollution by emerging OPEs warrants close attention.

Keywords: Anaerobic reductive dechlorination; Ecological risk; Legacy and emerging pollutants; Marine environment; Sources.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Biodegradation, Environmental
China
Environmental Monitoring
Esters / analysis
Flame Retardants* / analysis
Organophosphates / analysis
Phosphates / analysis
Polychlorinated Biphenyls* / analysis
Water Pollutants, Chemical* / analysis

Substances

Polychlorinated Biphenyls
Water Pollutants, Chemical
Flame Retardants
Organophosphates
Phosphates
Esters