Effects of hair dyeing on DNA damage in human lymphocytes.

Comet assays were carried out to evaluate DNA damage in human lymphocytes from 20 volunteers before and after hair dyeing. DNA damage in lymphocytes was found to be slightly higher in volunteers after hair dyeing. Tail moments before and after hair dyeing were 1.47 +/- 0.41 and 1.75 +/- 0.29 respectively (p<0.0008). DNA damage in lymphocytes showed significant difference with treatment and heating time. The tail moments after 15 min of treatment time before and after hair dyeing were 1.44 +/- 0.22 and 1.85 +/- 0.36, respectively (p=0.0004) and the corresponding tail moments in 20 min of heating time before and after were 1.37 +/- 0.15 and 1.78 +/- 0.34 (p=0.0002). In conclusion, we found that an acute exposure of hair dyes with heating caused DNA damages in peripheral lymphocytes and that this damage had significant association with treatment and heating time.