A Study On The Relationship Between The Occupational Exposure Of The Uranium Workers In Jiangxi Province And The DNA Damage

BackgroundUranium miners suffered from the dangerous of working environment and the hazard of chemical industry in mining and milling. In addition, the miners were mainly exposed to internal radiation of alpha particle produced by radon and its decay products and external radiation of gamma ray. The results from domestic and foreign researches were inconsistent about if the rate of chromosome aberration in peripheral blood lymphocytes among uranium workers was higher than control group. And less research was concerned the urinary8-Hydroxydeoxyguanine (8-OHdG) level of the people who were exposure to long-term low-dose radiation. This study tried to explore the relationship between the occupational exposure to the radiation and DNA damage of uranium miners through two different biomarkers relate to DNA damage.ObjectiveTo analyze the chromosome aberration of peripheral blood lymphocytes and estimate the urinary8-OHdG level of the uranium worker. To explored the relationship between the occupational exposure to the radiation and DNA damage of uranium miners and provide more scientific basic data for improving the level of radiation protection to uranium miners.MethodsA uranium development companies was chosen as the research field. A mixed method including survey and laboratory testing has been used. Field investigations and sample collections were carried on twice. In the first field work, a total of98uranium miners were randomly selected as uranium miner group. A total of48executive staffs or new employees were randomly selected as control group. The subjects were investigated by a questionnaire survey. Chromosome aberration analyses were performed on their blood samples. In the second field work, a total of99male uranium miners were randomly enrolled and divided into underground miner group and miller group. A total of44executive staffs or new employees were randomly enrolled into control group. The subjects were investigated by a questionnaire survey and their urinary8-OHdG levels were measured.1. Analysis of chromosome aberration in peripheral blood lymphocytesVenous bloods (0.7ml) with heparinization were collected and added into culture media. Cells were harvested at50-h. The slides were made by common method and assayed with Giemsa staining. U-test and negative binominal regression were used to analyze the data.2. Analysis of urinary8-Hydroxydeoxyguanine levelThe urinary8-OHdG levels were detected with ELISA Kits. The urine creatinine levels were determined by picric acid method. The urinary8-OHdG level were corrected by the urine creatinine. Chi-square test, analysis of variance and multiple linear regression were used to analyze the data.ResultsThe frequency of total aberration in uranium miner group was2.80%, while the control group was2.79%. There was no significant different between the two groups (u=0.02, p=1.96). The frequency of "dic+r" in uranium miner group was0.25%, while the control group was0.12%. The "dic+r" level in uranium miner group was about2times higher than in the control group and the difference has statistic significance (u=1.81, p=0.04). A negative binominal regression analysis was performed to study the effect of occupational exposure on the frequency of "dic+r". In the uranium miner group the "dic+r" level was5-6times higher than in the control group and the difference has statistic significance (u=2.28,p=0.02). The relationship between the frequency of "dic+r" and work year was studied because of lack of personal dose data. The frequency of "dic+r" tended to increase with work year, but it was not significantly different (u=1.95, p=0.05)The urinary8-OHdG level of55underground uranium miners is (64.91±60.06) ng/mgCr, while44millers was (52.08±23.31) ng/mgCr and44control workers were (51.50±29.36) ng/mgCr. No significant difference was observed among the three group workers (F=1.60, p=0.21). The level of urinary8-OHdG in underground miners and millers with working year from5to9is higher than those working year less than4and more than10years, but there was no significant difference among them (F=0.65, p=0.53; F=0.85, p=0.44)ConclusionThere was no evidence showing the total aberration level in uranium miner group was higher than the control group. But the "dic+r" level in the uranium miner group was significantly higher than the control group.The urinary8-OHdG level of uranium workers isn’t higher than control workers in this study.