Oxidative Stress Biomarkers among Residents measured 6 years after the Hebei Spirit Oil Spill

Abstract

In December 2007, the Hebei Spirit oil spill accident occurred on the west coast of South Korea. Among the local residents, a dose-response relationship between the exposure to crude oil and urinary oxidative stress biomarkers was reported previously, 1.5 years after the oil spill. The aim of this study was to examine possible longer term effects associated with the exposure to oil spill among the residents, six years after the oil spill, especially in terms of oxidative stress biomarkers. The target subjects were recruited based on the location of their residence and were also classified by their history of clean-up activities following the oil spill. In the vicinity of the oil spill, i.e., within 20 km from the oil spill site, a total of 476 adults (grouped as Near), and from the area beyond 20 km away from the spill site, 152 adults were recruited (grouped as Far) in 2014, respectivey. The participating adults were measured for 8–hydroxy–2–deoxyguanosine (8–OHdG) and malondialdehyde (MDA) levels in their 12-hour urine samples as indicators of oxidative DNA damage and lipid peroxidation, respectively. The subjects were also asked to fill the questionnaire. Multivariate general linear model was used to statistical analysis by SAS package (GLM procedure). The geometric means (geometric standard deviation) of the urinary oxidative stress biomarkers measured in the study population were 5.31 (1.78) μg/g creatinine and 2.15 (1.71) μmol/g creatinine for urinary 8–OHdG and MDA levels, respectively. Duration of clean–up activities and the distance of residence from the oil spill site, showed significant association with both 8–OHdG and MDA levels, even after adjusting for sex, age, income, and creatinine corrected cotinine levels. Even 6 years after the oil spill, positive associations between oxidative stress biomarkers and oil exposure were evident. While the present observation should be confirmed in other situations and populations, the results of this study suggest that the consequences of oil pollution may last for years. Health implication of this observation deserves further investigation.