Investigating Micronucleus Changes in Mouse Lymphocytes Due to Exposure to Silica Dust

Occupational exposure to silica dust has multiple consequences, including genetic complications. One of the genetic complications is Micronucleus (MN) changes; therefore, this study aims to evaluate the rate of MN formation in mouse lymphocyte cells due to exposure to silica dust.

Totally 72 male mice BALB/c were selected and categorized into five exposure groups with 12 mice in exposure to the concentrations of 1.3, 3, 8, 12, and 17 mg/m³ of 99% pure silica dust and a control group. The mice were exposed to silica dust in which they were exposed for 8 hours a day, 6 days a week, and for 1, 2, 3, and 4 months. Then, blood samples were taken from the mice and the rate of MN formation in their lymphocyte cells was evaluated. The results were analyzed via SPSS software version 21 (P<0.05).

Maximum and minimum averages of dust concentration, related to boxes 1 and 5, were 17 mg/m³ and 1.3 mg/m³, respectively. Maximum rate of MN formation was observed in the fourth month of exposure and in group 1 with the value of 21.6±1.15, and minimum rate of MN formation was observed in the third month of exposure and in control group with the value of 3±1. Average of MN frequencies in each of the exposure month was significant related to the control group (P=0.001). There was a direct and significant correlation between exposure concentrations of exposed group and average rate of MN formation (r=0.679).

More than 3 months exposure to silica dust may lead to significant MN formation in lymphocytes of mice BALB/c in comparison with the control group.