This article [1] has been retracted by the Editor. A committee at Soochow University has investigated this case and supports the decision to retract the article. Incorrect statistical methods were used to calculate mean and S.D. values and additional errors were made in determining 8-OHdG concentrations. It has come to light that Figure 1 and Figure 2 were published in a previous article [2]. The committee also found that some of the original data were missing. We apologize to the readership of Particle and Fibre Toxicology.