Exposure to Spilled Oil Constituents and Oxidative Stress in Inhabitants 1.5 years After the Hebei Spirit Oil Spill

Abstract

Background: The sinking of the oil tanker Hebei Spirit in December 2007 resulted in the spill of 12,547 kl of crude oil. The constituents mainly contained various volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and heavy metals. These compounds may cause oxidative stress. Aims: To evaluate the relationship between the levels of biological exposure markers and oxidative stress markers in residents living the affected area 1.5 years after the Hebei Spirit oil spill. Methods: Urinary metabolite of VOCs, trans,trans-muconic acid (t,t-MA), urinary metabolites of PAHs, 1-hydroxypyrene (1-OHP) and 2-naphthol, and blood and urinary heavy metals, blood lead, blood manganese, urinary cadmium, and urinary mercury were measured from 1,278 residents as biomarkers of spilled oil exposure. Urinary 8-hydroxy-2’-deoxyguanosine (8-OHdG) and urinary malondialdehyde (MDA) levels were analyzed in 789 residents as indicators of oxidative stress. Results: The urinary metabolites of PAHs, 1-OHP and 2-naphthol significantly increased as the distance from the oil spill site to the residence was closer. The concentrations of heavy metals in the body, especially cadmium and lead, consistently showed a positive relation with the number of days of clean-up activity participation in an immediate post-spill, total number of days of clean-up work in a prolonged period, distance from the early contaminated coastline to the residence, and distance from the oil spill point ton the residence. The levels of urinary PAHs and heavy metals in urine and blood were significantly related to the oxidative stress markers including 8-OhdG and MDA. Conclusions: The concentration of PAHs metabolites and heavy metals in the body showed a positive relation to the levels of oxidative stress biomarkers even 1.5 years after the accident. The mid- and long-term adverse health effects due to the oil spill exposure are a concern in inhabitants.