BaselineDNA damage caused by organic extracts of contaminated sediment, crude, and weathered oil and their fractions recovered up to 5 years after the 2007 Hebei Spirit oil spill off Korea

•Genotoxicity of polluted coastal sediment was assessed after oil spill accident.•Comet assay was carried out for the subfraction of sediment/oil extracts.•Most subfraction was higher in DNA damage than the sediment/oil organic extracts.•Antagonistic effect was found between genotoxic compounds in the organic extracts.•Potential genotoxicity still remained in sediments 5 years after oil spill accident.

We examined the degree of DNA damage caused by three fractions (F1, aliphatic hydrocarbons; F2, aromatic hydrocarbons; and F3, polar compounds) of the organic extract of sediments taken from Taean, Korea, following the Hebei Spirit oil spill. DNA damage was measured using the comet assay with blood cells of the striped beakfish (Oplegnathus fasciatus). DNA damage was also examined for fractions of crude oil (Iranian Heavy Crude Oil, IHC), weathered oil and six subfractions (F2.1-F2.6). The greatest DNA damage was found from the Sinduri dune region and DNA damage decreased to 40% weathered oil in F2 fraction compared with crude oil. The DNA damage of the sum of fractions was found higher than the organic extracts of sediments, suggesting antagonistic interactions between the genotoxic compounds. This study confirmed the persistence of potential genotoxicity in sediments of the severely affected regions as long as 5 years after the oil spill.