Changes in Chemical Composition and Copepod Toxicity during Petroleum Photo-oxidation
Title
Changes in Chemical Composition and Copepod Toxicity during Petroleum Photo-oxidation
Subject
Extraction
Paraffins
Biochemistry
Toxicity
Oil spills
Biomimetics
Polycyclic aromatic hydrocarbons
Marine pollution
Description
Photoproducts can be formed rapidly in the initial phase of a marine oil spill. However, their toxicity is not well understood. In this study, oil was irradiated, chemically characterized, and tested for toxicity in three copepod species (Acartia tonsa, Temora longicornis, and Calanus finmarchicus). Irradiation led to a depletion of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes in oil residues, along with an enrichment in aromatic and aliphatic oil photoproducts. Target lipid model-based calculations of PAH toxicity units predicted that PAH toxicities were lower in water-accommodated fractions (WAFs) of irradiated oil residues ("irradiated WAFs") than in WAFs of dark-control samples ("dark WAFs"). In contrast, biomimetic extraction (BE) measurements showed increased bioaccumulation potential of dissolved constituents of irradiated WAFs compared to dark WAFs, mainly driven by photoproducts present in irradiated oil. In line with the BE results, copepod mortality increased in irradiated WAFs compared to dark WAFs. However, low copepod toxicities were observed for WAFs produced with photo-oxidized oil slicks collected during the Deepwater Horizon oil spill. The results of this study suggest that while oil photoproducts have the potential to be a significant source of copepod toxicity, dilution and dispersion of these higher solubility products appear to help mitigate their toxicity at sea. 2022 American Chemical Society. All rights reserved.
Date
2022
Contributor
Katz, Samuel D.
Chen, Haining
Fields, David M.
Beirne, Erin C.
Keyes, Phoebe
Drozd, Greg T.
Aeppli, Christoph
Type
journalArticle
Identifier
0013936X
10.1021/acs.est.2c00251
Collection
Citation
“Changes in Chemical Composition and Copepod Toxicity during Petroleum Photo-oxidation,” Lamar University Midstream Center Research, accessed May 14, 2024, https://lumc.omeka.net/items/show/25592.