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@#<b>Objective</b> To investigate the effects of lowdose ionizing radiation (LDIR) on oxidative stress and damage repair in human bronchial epithelial (HBE) cells. <b>Methods</b> HBE cells were divided into 0, 50, 100, and 200 mGy groups, and cultured for 24 and 48 h after X-ray irradiation, respectively. The cell viability, levels of glutathione (GSH), malondialdehyde (MDA), and 8-hydroxy-2’-deoxyguanosine (8-OHdG), and transcriptional levels of DNA damage repair genes <i>PPP2R2D</i> and <i>TP53</i> were measured. <b>Results</b> At 24 h after irradiation, there was no significant difference in the cell viability between the dose groups and the control group (<i>P</i> > 0.05); all dose groups had significantly increased MDA level, dose-dependently decreased GSH level, dose-dependently increased 8-OHdG level, and significantly increased mRNA level of <i>PPP2R2D</i> gene (all <i>P</i> < 0.05); the mRNA expression level of <i>TP53</i> gene was significantly increased in the 50 mGy group (<i>P</i> < 0.05). At 48 h after irradiation, there were the highest cell viability, significantly decreased MDA and 8-OHdG levels, and significantly increased mRNA expression levels of <i>PPP2R2D</i> and <i>TP53</i> genes in the 50 mGy group compared with the control group (all <i>P</i> < 0.05); the GSH level in the 100 mGy group was significantly increased (<i>P</i> < 0.05). <b>Conclusion</b> LDIR, especially radiation at 50 mGy, can affect the oxidative-antioxidant level in HBE cells and the transcript-level differential expression of DNA damage repair genes.
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Due to the continuous development of nuclear power technology and the wide application of ionizing radiation in China, an increasing number of occupational groups and the general public have been exposed to the low-dose ionizing radiation environment. Consequently, research has focused on related health effects (carcinogenic and non-carcinogenic effects). There is no consensus on the health effects of long-term low-dose ionizing radiation exposure on populations. This article reviews the health effects of low-dose ionizing radiation identified worldwide to provide a scientific basis for investigating the mechanisms of such effects and developing population protection strategies.
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The lens of the eye has been recognized as one of the most radiosensitive tissues. It has been known that a radiation dose of 0.5 Gy or higher can induce radiation cataract. Studies have also demonstrated that long-term exposure to low-dose radiation can increase the risk of lens opacity. However, the specific biologic mechanism of lens opacity induced by low-dose ionizing radiation is still unclear. Many mechanism chains may induce opacity independently or jointly, such as genomic damage in lens epithelial cells, oxidative stress, defects in intercellular communication, and inflammatory reaction, and genetic and epigenetic factors may also play a role. This paper briefly reviews the mechanisms of low-dose ionizing radiation inducing lens opacity as well as the role of genetic susceptibility in its development and progression, in order to provide a scientific reference for the prevention and control of this disease.
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With the development of nuclear energy and the wide application of ionizing radiation, more and more occupational populations and the public are exposed to low-dose ionizing radiation. Consequently, the research on human health effects of exposure to low-dose ionizing radiation, including carcinogenic and non-carcinogenic effects, have become a hot topic in the field of public health. The biological effects caused by low-dose ionizing radiation mainly depend on the physical property, duration, dose, and dose rate of ionizing radiation. At present, there is no consensus on the effects of long-term exposure to low-dose ionizing radiation on human health. This article reviews the research on the health effects of long-term exposure to low-dose ionizing radiation at home and abroad, and provides a scientific basis for research on the health effects, influence mechanism, and protection strategies of long-term exposure to low-dose ionizing radiation.
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Objective:To investigate the effect of low-dose ionizing radiation on blood cell parameters of radiation workers.Methods:A total of 124 staff members engaged in radiology were selected into the observation group, and they were divided into 4 subgroups of physicians, physicists, technicians, and maintainer according to their jobs. A total of 130 non-radiation-related staff members from the same hospital were selected into the control group. Blood cell parameters of peripheral blood of all subjects from 2016 to 2019 were collected, and the differences in blood cell parameters between the radiation group and the control group as well as 4 subgroups of the control group were analyzed and compared, and the correlation between the differences in blood cell parameters and the cumulative radiation dose was compared.Results:Compared with the control group, the white blood cell count, neutrophil count, red blood cell count and hemoglobin count in the observation group were lower than those in the control group (all P<0.05). There are no significant differences in cumulative radiation dose among different types of work (all P>0.05). Correlation analysis showed that the blood cell parameters of peripheral blood cells were not significantly correlated with the cumulative radiation dose. The blood cell count changes after 4-year low-dose ionizing radiation between the physicist group, the technician group and the maintainer sub-group were significantly different (all P<0.05), but the above differences were not related to the cumulative radiation dose (all P>0.05). Conclusions:Under the same exposure and protection conditions, the blood cell counts of different radiation-related workers are not significantly different, and the long-term cumulative radiation dose has no significant correlation with blood cell parameters. Therefore, peripheral blood cell parameters can no longer be used as a good indicator to reflect radiation damage, and it is urgent to find more convenient, intuitive and sensitive indicators of radiation damage.
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Objective:To explore the impact of occupational ionizing radiation exposure on blood indicators including white blood cell（ WBC）， red blood cell （RBC）， hemoglobin （Hb）， platelet （PLT） were analyzed. Methods:A total of 237 medical radiation workers in Yangpu district， Shanghai were recruited and divided into observation group and control group， according to individual average dose of external exposure. The annual effective dose in observation group was 0.357 7-4.704 3 mSv， and the median dose was 0.536 8 mSv （0.441 2-0.893 8）. The annual effective dose in control group was 0.031 2-0.350 8 mSv， and the median dose was 0.199 2 mSv （0.143 8-0.252 8）. Routine blood tests were conducted twice in the occupational health examinations from 2017 to 2019 and the results were collected. Chi-square test， Mann-Whitney U test， and generalized estimating equations （GEE） model were used for statistical analysis. Results:Compared to the first examination， the risk of having abnormal Hb increased （OR=1.029， 95%CI： 1.006-1.053）. After adjusting the factors of age， gender， seniority and exposure time， the risk of Hb abnormality in the observation group was lower than that in the control group （OR=0.422， 95%CI：0.198-0.898）. There was no significant difference between the observation and control groups in the risk of abnormal WBC， RBC， and PLT. Conclusion:Exposure to occupational ionizing radiation may increase the risk of abnormal Hb， while there is no significant change in WBC， RBC and PLT. Radiation workers should have full protection at work and be under appropriate occupational health management.
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BACKGROUND@#Numerous studies have concentrated on high-dose radiation exposed accidentally or through therapy, and few involve low-dose occupational exposure, to investigate the correlation between low-dose ionizing radiation and changing hematological parameters among medical workers.@*METHODS@#Using a prospective cohort study design, we collected health examination reports and personal dose monitoring data from medical workers and used Poisson regression and restricted cubic spline models to assess the correlation between changing hematological parameters and cumulative radiation dose and determine the dose-response relationship.@*RESULTS@#We observed that changing platelet of 1265 medical workers followed up was statistically different among the cumulative dose groups (P = 0.010). Although the linear trend tested was not statistically significant (P@*CONCLUSION@#We concluded that although the exposure dose was below the limit, medical workers exposed to low-dose ionizing radiation for a short period of time might have increased first and then decreased platelets, and there was a dose-response relationship between the cumulative radiation dose and platelets changing.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Blood Platelets/radiation effects , Health Personnel/statistics & numerical data , Occupational Exposure/adverse effects , Prospective Studies , Radiation Dosage , Radiation Exposure/adverse effects , Radiation, IonizingABSTRACT
OBJECTIVE: To investigate the effects of long-term and low dose ionizing radiation on ocular lens opacities of residents living in areas with high natural radiation background(HNRB) in Yangjiang City, China. METHODS: A total of 483 Han residents from Yangjiang City(HNRB area) and 517 from Enping City(control area) were selected as study subjects using a cluster random sampling method. Questionnaire survey and lens examination were carried out. The risk factors of lens opacity and its severity were analyzed by logistic regression analysis. RESULTS: The prevalence rates of lens opacity, cortical opacity and posterior subcapsular opacity in HNRB area were higher than those in control area(60.7% vs 51.6%, 53.4% vs 46.8%, 21.9% vs 9.3%, all P<0.05). There was no significant difference in karyotype turbidity between HNRB area and control area(52.4% vs 47.6%, P>0.05). After adjusting for confounding factors including age, gender, cardiovascular/metabolic diseases, smoking, alcohol drinking and tea drinking, the unconditional logistic regression analysis results showed that the risk of ocular opacity, cortical opacity and posterior subcapsular opacity in residents of HNRB area was higher than that in control area(all P<0.05). Multivariate disordered logistic regression analysis results showed that residents in the HNRB area had a higher risk of grade two karyotype turbidity than grade one karyotype turbidity(P<0.01). Ordered logistic regression analysis results showed that residents in HNRB area had an increased risk of developing severe cortical turbidity(P<0.01). CONCLUSION: Long-term and low dose ionizing radiation exposure may increase the risk of ocular lens opacity, especially cortical and posterior subcapsular cataract, and affect the severity of the disease.
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Objective To investigate the effect of low dose ionizing radiation on blood pressure of radiation workers. Methods A total of 219 medical staff from a hospital in Wuhan were enrolled in the present study. Of them, 115 radiation workers were included in the low-dose ionizing radiation exposure group, the remaining 104 non-radiation workers were used as the control group. The blood pressure of the two groups was measured. The individual annual doses of the exposed group were collected. The independent sample t test was used to compare the blood pressure of the two groups. The linear regression model was used to analyze the relationship between the annual dose and blood pressure of the exposed group, and the logistic regression analysis method was used to analyze the relationship between hypertension and the annual dose of the exposed group. Results It was found that the mean blood pressure of the exposed group was significantly higher than that of the control group, and the difference was statistically significant (P<0.05). Linear regression analysis found that there was no significant correlation between the annual dose of the exposed group and blood pressure. Logistic regression analysis revealed that in the exposed group, women had a higher risk of hypertension than men, while the individual annual dose was not significantly associated with hypertension. Conclusion Women in radiation work were at higher risk than men, and low-dose ionizing radiation was not significantly associated with changes in blood pressure in radiation workers.
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Long-term exposure to low dose ionizing radiation contributes to the damage of radiosensitive tissue and organ in radiation workers.The main cytogenetic index used to evaluate radiation damage induced by chronic low dose ionizing radiation is the chromosome aberrations of peripheral blood lymphocytes.In this paper,the cytogenetic evaluation indicators of radiation workers exposed to low dose ionizing radiation were reviewed basing on the research achievements of domestic and foreign scholars.The goals of this review were to supply the present situation and limitation of chromosomal aberration analysis in peripheral blood lymphocytes of radiation workers and to provide a reference for the chromosomal aberration test and assessment of radiation workers in China.
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Mesenchymal stem cells (MSCs), which are multipotent and have self-renewal ability, support the regeneration of damaged normal tissue. A number of external stimuli promote migration of MSCs into peripheral blood and support their participation inwound healing. In an attempt to harness the potential beneficial effects of such external stimuli, we exposed human MSCs (hMSCs) to one such stimulus-low-dose ionizing radiation (LDIR)-and examined their biological properties. To this end, we evaluated differences in proliferation, cell cycle, DNA damage, expression of surface markers (CD29, CD34, CD90, and CD105), and differentiation potential ofhMSCs before and after irradiation with γ-rays generated using a ¹³⁷ CSirradiator.At doses less than 50 mGy, LDIR had no significant effect on the viability or apoptosis of hMSCs. Interestingly, 10 mGyofLDIR increased hMSC viability by 8% (p<0.001) comparedwith non-irradiatedhMSCs.At doses less than 50 mGy, LDIR did not induceDNA damage, including DNA strand breaks, or cause cellular senescence or cell-cycle arrest. Surface marker expression and in vitro differentiation potential of hMSCs were maintained after two exposures to LDIR at 10 mGy per dose. In conclusion, a two-dose exposure to LDIR at 10 mGy per dose not only facilitates proliferation of hMSCs, it alsomaintains the stem cell characteristics of hMSCswithout affecting their viability.These results provide evidence for the potential ofLDIRas an external stimulus for in vitro expansion of hMSCs and application in tissue engineering and regenerative medicine.
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Humans , Apoptosis , Cellular Senescence , Cell Proliferation , DNA , DNA Damage , In Vitro Techniques , Mesenchymal Stem Cells , Radiation, Ionizing , Regeneration , Regenerative Medicine , Stem Cells , Tissue EngineeringABSTRACT
Objective To explore the effect of low-dose ionizing radiation on the platelets and leukocytes of the radiation workers.Methods We collected data from a total number of 2 055 radiation related workers and with their cumulative doses.Data on platelets and leukocytes was gathered from physical examination of the staff members,from 2013 to 2015 in Chengdu.T test,variance analysis,x2 test,linear correlation,covariance analysis and multivariate logistic regression analysis were used to analyze the data.Results Results from the covariance analysis showed that with the increase of cumulative doses,the quantity of platelet and leukocyte appeared a decreasing trend.Multivariate logistic regression analysis showed that,with the increase of BMI levels and the medium cumulative dose and above (＞4.333 mSv),the risk of thrombocytopenia became more obvious (trend test as P＜ 0.05).In the group with high-dose exposure radiation (＞15.639 mSv) and combined factor as smoking,the risk of developing thrombocytopenia would increase (OR=2.33,95％ CI:1.23-4.44).Staff with cumulative dose of less than 4.332 mSv and exercised more than 1 time per week,the risk of developing low leukocyte would decrease (OR=0.26,95％CI:0.09-0.70).Conclusions Along with the increase of cumulative doses on exposure to radiation related workers.The quantity of platelet and leukocyte showed a decreasing trend among them.When this high-dose exposure radiation combined with overweight/obesity or cigarette smoking,the risk of developing thrombocytopenia was high.However,physical exercise might have served as protective factor on leukopenia.
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Objective To explore the effect of low-dose ionizing radiation on the platelets and leukocytes of the radiation workers.Methods We collected data from a total number of 2 055 radiation related workers and with their cumulative doses.Data on platelets and leukocytes was gathered from physical examination of the staff members,from 2013 to 2015 in Chengdu.T test,variance analysis,x2 test,linear correlation,covariance analysis and multivariate logistic regression analysis were used to analyze the data.Results Results from the covariance analysis showed that with the increase of cumulative doses,the quantity of platelet and leukocyte appeared a decreasing trend.Multivariate logistic regression analysis showed that,with the increase of BMI levels and the medium cumulative dose and above (＞4.333 mSv),the risk of thrombocytopenia became more obvious (trend test as P＜ 0.05).In the group with high-dose exposure radiation (＞15.639 mSv) and combined factor as smoking,the risk of developing thrombocytopenia would increase (OR=2.33,95％ CI:1.23-4.44).Staff with cumulative dose of less than 4.332 mSv and exercised more than 1 time per week,the risk of developing low leukocyte would decrease (OR=0.26,95％CI:0.09-0.70).Conclusions Along with the increase of cumulative doses on exposure to radiation related workers.The quantity of platelet and leukocyte showed a decreasing trend among them.When this high-dose exposure radiation combined with overweight/obesity or cigarette smoking,the risk of developing thrombocytopenia was high.However,physical exercise might have served as protective factor on leukopenia.
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Objective To explore the effects of 75 mGy irradiation on the apoptosis of spermatogenic cells and antioxidant capacity of serum and testis and hormone levels in male rats with diabetes mellitus(DM).Methods Rats were injected intraperitoneally with streptozotocin(STZ)to develop diabetes.The diabetic rats were irradiated with 75 mGy X-rays every other day for 4 weeks.Their survival rate and body weight were recorded 12 weeks after development of diabetes.The apeptosis percentage of germ cells was measured with flow cytometry and TUNEL method.The changes of anti-oxidation and gonadal hormone levels in serum and testis were measured with kits.Results After the rats suffered from diabetes for 12 weeks,the survival rate in DM group was 25%(6/24),100% in normal control group(16116).The survival rate in 75 mGy + DM group(9/16,56.25%)was obviously higher than that in the DM group(X2= 4.00,P < 0.05).Meanwhile,the percentage of apaptotic spermatogenic cells in the diabetic rats was significantly larger than those in the normal control and irradiation groups(F = 5.496,P < 0.05).MDA and NO levels in serum and testis of diabetic rats were higher in varying degrees than that in the normal control,while the serum and testis MDA content in the 75 mGy + DM group were lower than those in the DM group especially in the testis(F = 10.644,P < 0.01).75 mGy X-ray irradiation decreased NO content in the diabetic rats serum significantly(F = 14.379,P < 0.05)and increased NOS activity and TS,FSH level(F = 9.676,43.194 and 5.282,respectively,P < 0.05 and P < 0.01).Conclusions LDR could decrease the MDA level and NO content,and increase the antioxidant enzyme activity and TS and FSH levels in testis and serum of diabetic rats.
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OBJECTIVES: To assess the availability of the glycophorin A (GPA) assay to detect the biological effect of ionizing radiation in workers exposed to low-doses of radiation. METHODS: Information on confounding factors, such as age and cigarette smoking was obtained on 144 nuclear power plant workers and 32 hospital workers, by a self-administered questionnaire. Information on physical exposure levels was obtained from the registries of radiation exposure monitoring and control at each facility. The GPA mutant assay was performed using the BR6 method with modification by using a FACScan flow cytometer. RESULTS: As confounders, age and cigarette smoking habits showed increasing trends with GPA variants, but these were of no statistical significance. Hospital workers showed a higher frequency of the GPA variant than nuclear power plant workers in terms of the NO variant. Significant dose-response relationships were obtained from in simple and multiple linear regression models. The slope of the regression equation for nuclear power plant workers was much smaller than that of hospital workers. These findings suggest that there may be apparent dose-rate effects. CONCLUSION: In population exposed to chronic low-dose radiation, the GPA assay has a potential to be used as an effective biologic marker for assessing the bone marrow cumulative exposure dose.