Genotoxicity of arsenic evaluated by Allium-root micronucleus assay.

Arsenic exposure is associated with various diseases and cancers. By using Allium-root micronucleus (MN) assay, possible genotoxicity of sodium arsenite (0.3-100 mg/l) and arsenic trioxide (0.05-50 mg/l) was evaluated in this study. Our results showed that arsenic compounds induced MN formation concentration-dependently. Exposure to 0.5-20 mg/l arsenic trioxide or to 1-100 mg/l sodium arsenite caused MN significantly in meristematic cells and daughter cells of Allium roots. A time-course study revealed that MN increased significantly after a short term (1 h) exposure to 10 mg/l sodium arsenite, demonstrating an effective rapid response. Arsenic compounds also caused mitotic delay and a concentration-dependent decrease in mitotic index. Results of the present study suggest that Allium-root MN assay is a simple, efficient and reproducible method for the genotoxicity monitoring of arsenic water contamination.