A previous study related to DNA damage in work- ers occupationally exposed to X-rays showed a signif- icant correlation between age and DNA damage index in the comet assay31). In the present study, no correla- tion was observed between age and the DNA damage index in the exposed group, which is in agreement with other studies showing no correlation between age and the DNA damage index34,35). However, in X-ray-exposed personnel, the DNA damage index was significantly correlated with time of exposure or expe- rience as reported by various studies29−31).
In the past, several studies on monitoring DNA damage caused by occupational exposure have demon- strated the damage caused by smoking30,31). Tobacco smoke contains a high number of mutagenic and carcinogenic substances; hence, smoking is one of the important variables and therefore should be considered in biomonitoring studies. Cigarette smoke extract has been shown to have carcinogenic and mutagenic activ- ities in rodents and human cells during in vitro stud- ies32). Smoking has been associated with increased DNA damage in a study conducted both on young and old individuals33). Furthermore, an increase in DNA damage has also been reported in the workers of a cigarette factory34). The level of DNA damage is closely related to the intensity of smoking; therefore, the level of DNA damage in individuals who quit
smoking has been shown to decrease over the course of 1 year35). In contrast, some studies have reported no difference in terms of DNA damage between smokers and nonsmokers36,37). In the present study, no correlation was established between the smok- ing and nonsmoking radiation technicians. Certain studies have reported that cigarette smoking is not a significant confounding factor for the comet score42−45) and this may be the possible reason for nonsignifi- cant correlation of the DNA damage index observed between smokers and nonsmokers.
The results of the present study confirmed the harmful effects of X-rays on human DNA. These radiations-imposed genotoxic effects can cause signifi- cant DNA damage in radiology personnel during their occupational exposure. The increase in DNA damage may be attributed to handling of X-ray examinations without the use of any protective measures; therefore, the DNA damage in the workers using a lead apron was lower than in those who did not use a lead apron. Thus radiation personnel need to be aware about the hazards associated with excessive exposure to radia- tion.
This study recommends reduction of the exposure duration in any radiation area because the radiation dose received by a person is closely related to the time spent in the radiation area. The current study emphasizes proper use and storage of good qual- ity lead aprons to minimize X-ray penetration and it should be made compulsory for hospital adminis- trations to take proper steps to reduce exposure to X-rays in the workplace. Individual biomonitoring should be conducted regularly, and new radioprotec- tion policies should be introduced on the basis of genetic studies like the present one.
Acknowledgments: We are thankful to the University of Peshawar for providing financial support (grant no. 2583-80) and research facilities to complete this research work. We are also thankful to all the subjects who voluntarily participated.