First step in the evaluation of the effects of Prestige oil on the shore environment: Availability, bioaccumulation and DNA damage

Abstract

The Prestige oil tanker shipwrecked off the coast of Galicia (Spain) in November 2002, spilling nearly 63,000 tons of heavy oil, classified by the International Agency for Research on Cancer as possible human carcinogen. In this work, mussels (Mytilus galloprovincialis) were exposed to Prestige oil in the laboratory (1.5 and 3 ppm). Samples of seawater and mussel tissues were taken on days 7 and 14 of the experiment to determine the availability and bioaccumulation of the polycyclic aromatic hydrocarbons (PAH) contained in the oil and the DNA damage induced by the exposure using the comet assay. Seawater was renewed on day 14 and new samples were taken on day 21 to analyze the recovery ability of the mussels. Total PAH (TPAH) contents in seawater from the exposure tanks were higher than in the control tank, and this content was higher in the lower oil-dose tank due to the tendency of PAH to link to particles in water. Exposed mussels had much higher TPAH levels than controls, increasing with time even during the recovery phase. The correlation coefficient obtained demonstrated a clear environmental dose/internal dose relationship. Significant increases in DNA damage were observed in oil-exposed individuals in relation to controls, similar in the two doses tested. The DNA damage was constant during the exposure period but increased during the recovery time, reflecting the strand breakage during the DNA repair processes. The results obtained have shown the importance of determining the presence of pollutants in the environment, their bioaccumulation in organic tissues and their effects on the exposed organisms, in order to perform an integrated approach to evaluate the impact of contamination events in the aquatic environment.