Novel organophosphate esters and their transformation products in offshore sediment from Eastern China: Occurrence, temporal trend, and risk assessment

Meng Gao; Yu Wang; Liman Wei; Siyuan Li; Qiuyue Zhang; Zhongkang Yang; Mohan Bai; Yiming Yao; Lei Wang; Hongwen Sun

Environment International (Jan 2025)

Novel organophosphate esters and their transformation products in offshore sediment from Eastern China: Occurrence, temporal trend, and risk assessment

Meng Gao,
Yu Wang,
Liman Wei,
Siyuan Li,
Qiuyue Zhang,
Zhongkang Yang,
Mohan Bai,
Yiming Yao,
Lei Wang,
Hongwen Sun

Affiliations

Meng Gao: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
Yu Wang: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Corresponding authors at: Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, China.
Liman Wei: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
Siyuan Li: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
Qiuyue Zhang: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
Zhongkang Yang: Key Laboratory of Agricultural Environment in Universities of Shandong, College of Resources and Environment, Shandong Agricultural University, Tai’an 271000, China
Mohan Bai: Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China; Corresponding authors at: Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, China.
Yiming Yao: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
Lei Wang: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
Hongwen Sun: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China

Journal volume & issue: Vol. 195
p. 109205

Abstract

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Offshore sediment serves as an important sink for traditional organophosphate esters (TOPEs) originating from terrestrial sources. However, the contamination characteristics of novel OPEs (NOPEs) and their hydrolyzed and hydroxylated transformation products (Di- and OH-OPEs) in marine sediment are still unknown. In this study, 34 OPE-associated contaminants were measured in six offshore sediment cores (71 samples) collected from Eastern China. The total concentrations of Σ15TOPEs, Σ3NOPEs, Σ9Di-OPEs, and Σ7OH-OPEs in surface sediments were 3.16–73.4, n.d.–16.3, 4.48–21.4, and 0.14–0.42 ng g−1, respectively. NOPE compounds, such as tris(2,4-di-tert-butylphenyl) phosphate and its diester product, exhibited high contamination levels, primarily due to their high hydrophobicity and extensive industrial applications. Additionally, atmospheric transportation, along with wet and dry deposition and ocean currents, plays a crucial role in their distribution in offshore sediment. The location conditions and historical usage also influenced the vertical distributions of OPE-associated contaminants in sediment cores. Notably, a concentration peak of bis(2,4-di-tert-butylphenyl) phosphate (B2,4DtBPP) was dating back to 1940s, indicating the early usage of antioxidant tris(2,4-di-tert-butylphenyl) phosphite. Furthermore, a risk quotient (RQ) model was employed to assess the ecological risks posed by OPEs. Generally, the acute toxicity-based predicted no-effect concentrations for studied compounds were 1 to 2 orders of magnitude lower than those based on chronic toxicity. NOPEs and B2,4DtBPP exhibited high ecological risks, with maximum RQ values of 1570–4877 based on acute toxicity and 93.4–197 based on chronic toxicity. Notably, ΣRQ values for NOPEs were significantly higher than those of TOPEs (Mann-Whitney U test, p < 0.001), indicating their severe ecological risks in offshore sediment. Therefore, given the continuous input and considerable persistence of NOPEs in offshore sediment, their toxic effects and mechanisms warrant thorough investigation. This study provides the first evidence for the occurrence, temporal trends, and potential risks of NOPEs in marine sediment environment.

Published in Environment International

ISSN: 0160-4120 (Print)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Geography. Anthropology. Recreation: Environmental sciences
Website: https://www.journals.elsevier.com/environment-international

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