Evaluation of Dna Damage in Blood Lymphocytes of Iranian Silica Miners Using Comet Assay



Abdollah G¹ ; Farideh G¹ ; Mojtaba K² ; Mehdi Y³ Show Affiliations
Source: Annals of Tropical Medicine and Public Health Published:2018

Abstract

Background and objectives: Occupational exposure to silica dust in the silica mines is several times more than other mines. Silica dust can cause different complications in body tissues. One of damages caused by exposure to silica is the effects of oxidation that can lead to DNA fragmentation. The aim of this study was to assess the extent of damage DNA in blood lymphocytes of Iranian silica miners using Comet assay. Material and methods: 70 Iranian silica miners with at least five years history of exposure to silica and 48 healthy administrative staff with non-exposure to silica and other chemicals were randomly selected. The DNA damage levels were determined using the Comet assay under fluorescence microscope and Comet score software. The obtained results were analyzed using SPSS version 19, t-test and Pearson's correlation coefficient. Results: The age of subjects exposed to silica and control were respectively 44.5±7.6 and 41.3±10.3 years and Work experience of exposed and control was 22.5±7.6 and 18.2±10.3 and there were no significant differences in parameters including age, height, weight, work experience, BMI and blood pressure between two groups. The tail length (µm) was 3.2±0.98 and 11.52±5.2 in the exposed and control groups, respectively. The tail DNA% was 1.8±0.52 and 4.2±1.92 in the exposed and control groups, respectively. The tail moment (µm) was 0.81±0.21 and 1.9± 0.9 in the exposed and control groups, respectively. The DNA damage was significantly different for all three parameters between the two groups (p<0.001). In addition, there was a significant linear relationship between the level of DNA damage and work experience in the exposed group (p<0.001). Conclusion: The silica dust can increase DNA damage in blood lymphocytes of exposed workers and this fragmentation enhances by prolonging exposure. © 2018 Wolters Kluwer Medknow Publications. All rights reserved.