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Objective:To investigate the exposure level of ionizing radiation in medical radiation workers in Guangdong province, as well as their abnormality in the lens of the eye, and to analyze associated influence factors.Methods:In this study, 1 501 radiation workers from 60 hospitals were selected by using convenient sampling method for retrospecotive analysis of absorbed doses ( DL) to the lens of the eye, health examination information and the relevant influence factors. Results:The median value M and the 25 th and 75 th percentile values ( P25, P75)of the distribution of absorbed doses were 4.86, 2.99 and 7.90 mGy, respectively. The median values for male and female were 5.14 and 3.94 mGy, respectively. The median values for the Levels I, Ⅱ and Ⅲ medical institutions were 2.95, 3.51 and 5.06 mGy, respectively. The median values were radiotherapy 4.05 mGy, radiodiagnosis 4.84 mGy, interventional radiology 5.39 mGy and nuclear medicine 6.71 mGy, as well as nurses 3.48 mGy, physicians 5.03 mGy and technologists 5.03 mGy, respectively. There were statistically significant differences in dose distribution for different gender, age, length of radiation service, age at the beginning of radiation exposure, level of medical institution, occupational category and post ( Z=-6.72, H=389.64, 511.17, 70.29, 53.29, 49.06, 39.89, P<0.05). The detectable rate for increased cortical density of lens was 22.45% (337/1 501) and for lens turbidity was 8.19% (123/1 501). The detectable rate of increased cortical density showed a linear increasing trend with the increase in age, age of radiation service, age at the beginning of exposure to radiation, level of medical institution and dose ( χ2=366.36, 313.77, 15.18, 21.61, 92.13, P<0.05). The detectable rate of lens opacity increased linearly with the increase in age, length of radiation service, level of medical institution and dose( χ2=69.64, 67.65, 67.65, 37.37, P<0.05), and decreased linearly with the increase in age at the beginning of radiation exposure ( χ2=4.25, P<0.05). Logistic regression analysis showed that age was the influencing factor of increased cortical density ( χ2=165.98, P<0.05), and the risk of cortical densification increased with age ( OR=1.33, 95% CI: 1.27-1.39). Age, length of radiation service and occupation were the influencing factors of lens opacity ( χ2=25.78, 4.99, 6.88, P<0.05). The risk of lens opacity increased with age ( OR=1.17, 95% CI: 1.10-1.24). The risk of lens opacity increased with age of radiation service ( OR=1.06, 95% CI: 1.01-1.12). The risk of ocular opacity was higher in interventional radiology than that in diagnostic radiology, radiotherapy and nuclear medicine ( OR=2.59, 95% CI: 1.27-5.25). Conclusions:Long-term exposure to low dose ionizing radiation has a certain correlation with the abnormal lens detectable rate of medical radiation workers. Age, length of radiation service and occupation are the influencing factors of lens opacity.
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OBJECTIVE: To investigate the subjective symptoms of eyes induced by laser radiation in workers and its related influencing factors. METHODS: A total of 82 workers exposed to laser radiation were taken as exposure group, and 71 workers without laser radiation exposure as control group by judgment sampling method. The questionnaire survey and subjective symptoms of eyes were surveyed in these two groups. The work-site surveys of laser radiation job posts and laser irradiation testing were conducted to evaluate the exposure level of laser radiation on each post. The basic eye use and eye discomfort symptoms were investigated. RESULTS: The median of the laser radiation in 12 workplaces was 2.18×10~(-5) W/cm~2, and it was below occupational exposure limit(2.22×10~(-3) W/cm~2). The total detection rate of subjective discomfort of eyes in the exposed group was significantly higher than that in the control group(35.4% vs 15.5%, P<0.05). The results of multivariate logistic regression analysis indicated that laser exposure and smoking were the risk factors of subjective symptoms of eyes(P<0.05). CONCLUSION: Laser radiation operation has the risk of causing the subjective symptoms of eyes in exposed workers.
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OBJECTIVE: To explore the effect of delayed pre-job occupational health examination on occupational health surveillance by analyzing the results of pre-job occupational health examinations in radiation exposed workers. METHODS: A convenience sampling method was used to select 1 385 radiation workers as the research subjects in Guangdong Province in 2016 at a pre-job occupational health examination. Workers who did not engage in radiation work were selected as control group. Workers who engaged in radiation work but did not take pre-job occupational health examinations were selected as observation group. The difference of the results of occupational health examination between the two groups was analyzed. RESULTS: The proportion of the observation group was 55. 8%(773/1 385). The abnormal rates of the white blood cell( WBC) count,“double + ring”rate and lens in the observation group were higher than those in the control group(9. 3% vs 5. 7%,6. 0% vs 3. 6%,6. 2% vs 3. 6%,P < 0. 05),respectively. The WBC count in the observation group was lower than that in the control group [(6. 1 ± 1. 5) × 10~9/L vs(6. 7 ± 1. 5) × 10~9/L,P < 0. 01]. The contents of the thyroid stimulating hormone and triiodothyronine in the observation group were higher than those in the control group[(1. 3 ± 0. 4) m U/L vs(1. 2 ± 0. 3) m U/L,(1. 8 ± 0. 4) nmol/L vs(1. 7 ± 0. 5) nmol/L,P < 0. 01]. The tetraiodothyronine level in the observation group was lower than that in the control group [( 110. 8 ± 22. 4) nmol/L vs(113. 8 ± 23. 2) nmol/L,P < 0. 05]. CONCLUSION: The delay of pre-job occupational health examination of radiation exposed workers affects the examination results and the accuracy of basic health records.
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OBJECTIVE: To establish the dose-response curve of chromosome aberration induced by X-ray irradiation in human peripheral blood in vitro. METHODS: The median cubital vein blood of healthy male donors were collected and irradiated with X-ray at the dose of 0. 00-5. 00 Gy in vitro. The dose rate was 0. 8 mGy/s. The cells were cultured with colchicine and stained with routine Giemsa staining. The slices were blindly examined. The morphology of chromosomes were recorded as dicentric,multi-centric,dicentric plus rings or fragments( hereinafter referred to as dicentric + ring) in metaphase cells. The occurrence of dicentric + ring and the irradiation dose was used to create the dose-response curve.RESULTS: The results showed that the occurrence of dicentric + ring in abnormal cells increased with the increasing irradiation dose in the range of 0. 00-5. 00 Gy( P < 0. 01). The best fitting equation of 0. 00-1. 00 Gy is y = 23. 22 D2+4. 768 D-0. 018( P < 0. 01). The best fitting equation of 0. 50-5. 00 Gy is y = 34. 23 D-3. 072( P < 0. 01).CONCLUSION: The fitting degree of dose-response curve is good,which can be used as reference in laboratory to assess irradiation exposure dose.
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OBJECTIVE: To analyze the growth arrest and DNA damage gene 45( GADD45) mRNA expression in peripheral blood of radiation workers,and its relationship with exposure dose. METHODS: Using a typical sampling method,97 radiation workers from a hospital of Guangdong were selected as radiation group,48 hospital administrative staff without exposure to radiation and other occupational hazard factors were selected as control group. The real-time quantitative polymerase chain reaction was used to detect GADD45 mRNA expression of two groups. With the use of thermoluminescence dosimetry,we detected and collected personal dose data of radiation group over the past year. RESULTS: The GADD45 mRNA relative expression of the radiation group was higher than that of the control group( P < 0. 01).There was no correlation between GADD45 mRNA relative expression and factors such as personal dose,sex,age,length of service,smoking,and alcohol drinking( P > 0. 05). CONCLUSION: The ionizing radiation can lead to up-regulation of GADD45 mRNA expression in peripheral blood of radiation workers,but there was no linear relationship between GADD45 mRNA expression and its personal dose.
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OBJECTIVE: To investigate the occupational stress level of radiation exposed workers in Guangdong Province and explore the factors that influence occupational stress. METHODS: By random sampling method,306 radiation workers of Guangdong Province were selected in this study. The simplified Chinese version of Effort-Reward Imbalance( ERI)questionnaire was used to assess occupational stress levels. The scores of 3 dimensions including external effort,reward and internal commitment and their differences were analyzed. RESULTS: The scores of external effort,reward and internal commitment of 306 radiation workers in this study were( 15. 83 ± 5. 18),( 46. 63 ± 9. 06) and( 14. 97 ± 2. 23),respectively. There were 42 workers( 13. 73%) who had self-detected the occupational stress resulted from effort-reward imbalance; 62 workers( 20. 26%) were at high-risk of occupational stress. Compared with the industrial radiation workers,the scores of external effort and detection rate of occupational stress of hospital radiation workers were higher( P < 0. 05),while the high risk detection rate of occupational stress was lower( P < 0. 05). Compared with the female radiation workers, male workers had higher scores of external effort, effort / reward ratio and the detection rate of occupational stress( P < 0. 05) and lower scores of the reward score( P < 0. 05). The scores of external effort of radiation workers with junior college educational level or above were higher than those with senior high school educational level or below( P < 0. 05). CONCLUSION: The occupational stress level of radiation exposed workers has multiple influencing factors.It is recommended to strengthen the social support to improve their social and working environment,in order to reduce their occupational stress level.