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Objective To analyze and set up the effective dose of different ionizing radiation for tunnel construction workers. Methods A total of five tunnels constructed using drilling and blasting methods were selected as the research subjects using the convenient sampling method. The workplace γ radiation effective dose, radon concentrations, and radioactive activity concentrations were detected, and on-site surveys were conducted to estimate the internal and external irradiation doses and total effective doses for workers in different work sites. Results Radiological hazards in tunnels constructed using drilling and blasting methods included radon and its progeny, γ radiation, radioactive dust (uranium-238, radium-226, thorium-232, and potassium-40) and others. The average total effective dose of ionizing radiation exposure for tunnel construction workers was (6.730 1±1.541 1) mSv. The average dose of radon and its progeny was (6.163 0±1.512 8) mSv, radioactive dust was (0.014 6±0.009 1) mSv, γ radiation was (0.552 6±0.138 7) mSv. The dose of radioactive dust of radon and its progeny was 0.24%. Radon and its progeny contributed more to the radioactive dose than radioactive dust and γ radiation (all P<0.05). Among all the radioactive dusts, the dose contribution ranked from highest to lowest was thorium-232, uranium-238, and radium-226. Conclusion For tunnel construction workers, the largest contribution to the effective dose of ionizing radiation exposure is from radon and its progeny for internal irradiation, followed by γ radiation for external irradiation. The contribution of radioactive dust to internal irradiation dose can be considered negligible.
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Background Most of the studies on grading and classification of occupational health compre-hensive risks for specific employers still remain in the establishment and description of methodology, and practical application studies are rarely reported. Objective To explore the application of an occupational disease hazards comprehensive risk assessment method issued by the National Disease Control and Prevention Bureau in conjunction with the National Health Commission and a self-developed occupational health grading and classification method in petroleum refining enterprises, and to provide practical experience for the implementation of differentiated law enforcement by relevant regulatory authorities. Methods Two occupational health grading and classification methods were practiced in three petroleum refining enterprises in Guangdong Province. The occupational hazards comprehensive risk assessment method was provided by the Notice on Carrying out Pilot Work of Occupational Health Classification Supervision and Law Enforcement of the National Disease Control and Prevention Bureau and the National Health Commission. The principle was to derive the occupational health risk level according to nature of occupational hazards, exposure level, and number of workers exposed to them in an employer, and then to classify them into Class A, Class B, and Class C by combining with local occupational health management status level. The occupational health grading and classification method was self-developed according to available domestic and foreign occupational health risk assessment methods. Its principle was to calculate the risk level of each workstation in an employer based on published carcinogenicity classification or LD50/LC50 of chemical toxicants, level of noise, exposure parameters such as exposure level and exposure frequency, estimate the comprehensive risk Ro of the target employer by the Romanian comprehensive risk calculation method, and then calculate a comprehensive risk Ro' weighted by the occupational health management index of the target employer and classify it into class A, class B, and class C. Finally, assessment results, scope of application, inquired indicators, advantages,disadvantages and professional competence requirements of the two grading and classification methods were compared. Results The occupational hazards that were evaluated in three enterprises in this study were benzene, toluene, xylene, gasoline, hydrogen sulfide, and noise. The exposure levels of benzene, toluene, xylene, and gasoline were all below 10% OEL (occupational exposure limit), and hydrogen sulfide and noise were disqualified. Occupational hazards such as benzene and hydrogen sulfide were serious occupational hazards in the three enterprises, and the number of workers exposed was 461, 912, and 224, respectively; the HRs (hazard ratings) of benzene, toluene, xylene, gasoline, hydrogen sulfide, and noise were level 5, 3, 2, 3, 5, and 3 respectively. The occupational health management status of the three enterprises was graded as B, A, and B, respectively by the occupational disease hazards comprehensive risk assessment method. The occupational health management index of the three enterprises was graded as B, A, and A, respectively by the occupational health grading and classification method. The comprehensive risk assessment results showed that two enterprises classified into as the highest class C and one into class B by the occupational disease hazards comprehensive risk assessment method, while all three enterprises were classified into class B by the occupational health grading and classification method. Conclusion The two grading and classification methods are not consistent in the evaluation results of petroleum refining enterprises, and there are differences in the evaluation scope, indicators to be collected, and professionalism. It is recommended that occupational health regulators should fully consider the advantages and disadvantages of the two methods and choose the appropriate assessment method according to the actual regulatory purpose.
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OBJECTIVE: To compare the applicability of two risk assessment methods to assess the occupational health risk of key industries of dichloromethane in Shenzhen City. METHODS: The Singapore ministry of manpower risk(MOM) method and the comprehensive index method were used to evaluate the risk of 123 positions in 47 key industries of dichloromethane in Shenzhen City. Then the risk classification results of the two assessment methods were compared. RESULTS: The results of MOM method showed that the median and the 0 th to 100 th percentile [M(P_0-P_(100))] of risk of dichloromethane in electronics industry was 2(2-3), and the risk level was low to medium. The M(P_0-P_(100)) of risk of dichloromethane in printing industry was 2(2-4), and the risk level was low to high. The results of the comprehensive index method showed that the M(P_0-P_(100)) of risk of dichloromethane in electronics industry and printing industry were 3(3-4), and the risk level was medium to high. There was no significant difference in the assessment results of occupational health risk of dichloromethane between the electronic industry and the printing industry by MOM evaluation method(P>0.05). The occupational health risk assessment of dichloromethane in printing industry was higher than that in electronic industry by the comprehensive index method(P<0.01). Both evaluation methods were not consistent in the electronics industry and the printing industry(k values were-0.01 and 0.04, all P>0.05). After merging the evaluation results of the two industries, there was no consistency in the evaluation results of the two evaluation methods(k value=0.01, P>0.05). CONCLUSION: The risk level of dichloromethane in printing industry is higher than that in printing industry in Shenzhen City. The comprehensive index method may comprehensively and objectively assess the occupational health risk level of dichloromethane in key industries in Shenzhen City.
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Objective:To investigate the effect of long-term low dose ionizing radiation on the levels of interleukin (IL) and TGF-β1 in the population in high background radiation area(HBRA).Methods:Appropriate amount of peripheral blood was drawn from 41 and 44 healthy men aged 45-65 years who were randomly selected from Tangkou town of Yangjiang city (HBRA) and Hengpo town of Enping city (control area, CA), respectively. After centrifugation and stratification, the upper plasma of blood was separated to determine IL-2, sIL-2R, IL-4, IL-5 and TGF-β1 by using ELISA. The difference of plasma IL of the residents in those two regions was analyzed. The influence of region, age, smoking, drinking and income on the indexes of ILs and TGF-β1 was evaluated by Covariance analysis.Results:The concentration of IL-2 at HBRA area was slightly higher than those in the control area, but the other indexes were lower than those in CA residents. The differences of IL-5 ( t=7.124, P<0.001) and TGF-β1 ( t=4.900, P<0.001) between two areas were significant statistically. Covariance analysis showed that smoking had a significant effect on IL-2 level ( F=5.283, P<0.05). Conclusions:Under the influence of long-term low-dose ionizing radiation, all kinds of plasma interleukin levels of residents in HBRA were different with that in CA. The immune balance was biased towards Th1 type cytokines, and the immune function in HBRA was slightly stronger than that in CA, suggesting that long-term chronic low-dose ionizing radiation may induce adaptive changes in the immune function, which needs further study.
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OBJECTIVE: To explore the status of occupational stress and its influencing factors in medical radiation workers using two occupational stress measurement models. METHODS: A total of 632 medical radiation workers from Guangdong Province were selected as the study subjects using cluster sampling method. Chinese version of Job Content Questionnaire and Effort Reward Imbalance Questionnaire were used to assess occupational stress with job demand-control( JDC) and effort-reward imbalance( ERI) models. RESULTS: The rate of occupational stress in the study subjects was 43. 8%( 277/632) using the JDC model. The rate of occupational stress was 38. 6%( 244/632) using the ERI model. The multivariate logistic analysis results showed that the risk of JDC occupational stress was higher in workers with more than 8 hours work daily and more than 40 hours weekly( P < 0. 01). The risk of ERI occupational stress was higher in the workers with age of30. 0-40. 0,public medical institutions,daily work more than 8 hours and weekly work more than 40 hours( P < 0. 01).CONCLUSION: Under the two theoretical models,medical radiation workers have a certain degree of occupational stress. The age,medical institution type,daily and weekly work hours are the main factors affecting occupational stress.
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Objective@#To apply the semi-quantitative risk assessment model in the Technical Guidelines for Occupational Health Risk Assessment of Chemical Hazardous Factors in the Workplace to assess the occupational health risk of electroplating enterprises and explore its applicable conditions and characteristics.@*Methods@#Three electroplating enterprises were selected as the research objects. Occupational hygiene survey and hazard factor detection were conducted on the spot. Three semi-quantitative risk assessment methods were used to assess the risk, and the evaluation results were compared.@*Results@#The consistency between the contact index method and the comprehensive index method was strong. The weighted Kappa value was 0.946 and the P value was less than 0.001, but the consistency between the contact ratio method, the contact index method and the comprehensive index method was poor. The weighted Kappa value was 0.345 and 0.391, and the P value was 0.009 and 0.004, respectively. When the contact concentration is less than 50% OELs, the evaluation results of the contact ratio method are lower than those of the exponential method and the comprehensive exponential method. The consistency of the three methods was the highest when the contact concentration (>50%) and (<OELs). When the contact concentration >OELs, the results of the contact ratio method are higher than those of the index method and the comprehensive index method.@*Conclusion@#Contact ratio method is suitable for occupational health risk assessment under the condition of incomplete occupational health information and for enterprise managers to identify key control points of health risk through self-assessment; Contact index method is suitable for hazard risk assessment of occupational hazards without sampling test conditions or OELs, and pre-assessment of occupational hazards of construction projects without access to analogical test data. The index method is suitable for occupational health risk assessment with available testing data and complete occupational health information.
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Objective@#To explore the relationship between occupational stress, psychological capital and depressive symptoms among electronic manufacturing female workers in the Pearl River Delta region.@*Methods@#Using cluster sampling method, 845 female workers from 5 electronic manufacturing enterprises in the Pearl River Delta region were selected as research subjects from June to August 2017. The Effort Reward Imbalance questionnaire (ERI) , Psychological Capital questionnaire-24 (PCQ-24) and Patient Health questionnaire-9 (PHQ-9) were applied to measure the level of occupational stress, psychological capital and depressive symptoms in female workers.@*Results@#Effort (r=0.197, P<0.01) and over commitment (r=-0.260, P<0.01) were positively correlated with the score of depressive symptoms, and the rewards was negatively correlated with depressive symptoms (r=-0.211, P<0.01) . The reward and over-commitment for depressive symptoms were accounted for 8.2%. Psychological capital was negatively correlated with depressive symptoms, and plays a partly mediating role in the relationship between occupational stress and depressive symptoms of female workers. The psychological capital for depressive symptoms was accounted for 8.7%.@*Conclusion@#Occupational stress can affects the depressive symptoms of electronic manufacturing female workers, or indirectly affect depressive symptoms through psychological capital, reduce occupational stress and improve psychological capital as a way to relieve the depressive symptoms of female workers.
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OBJECTIVE: To explore the effect of occupational stress on the level of salivary cortisol in electronic manufacturing workers. METHODS: Two hundreds and forty workers were selected as study subjects by cluster sampling method. The Job Content Questionnaire and the Effort-Reward Imbalance Questionnaire were used to investigate the level of occupational stress in the job demand control( JDC) model and effort reward Imbalance( ERI) model. The saliva samples of workers were taken to determine the cortisol levels. RESULTS: Among the 240 workers,172( 71. 7%) showed occupational stress based on JDC model and 59( 24. 6%) showed occupational stress based on ERI model. The level of salivary cortisol of the workers in the high occupational stress group of JDC and ERI model were higher than those of the low occupational stress group( P < 0. 01). The level of salivary cortisol was positively correlated with the score of job demands,external costs and internal inputs( P < 0. 01),and it was negatively correlated with score of return dimension( P < 0. 01). In the occupational stress of JDC model,job requirements and autonomy entered the regression equation( P < 0. 05),that explained the 14. 0% of the total variation of the equation. In the occupational stress of ERI model,job pay and return dimension entered the regression equation( P < 0. 05),that explained the 13. 0% of the total variation of the equation. CONCLUSION: There is a correlation between occupational stress and level of salivary cortisol in the electronic manufacturing workers. Salivary cortisol can be used as an indicator of occupational stress.
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OBJECTIVE: To investigate the current status and influencing factors of occupational stress in female workers of labor-intensive enterprises. METHODS: Totally 910 female workers from 5 labor-intensive enterprises in Guangdong Province was selected as the research subjects by random cluster sampling method. A questionnaire survey on occupational stress was conducted using the Occupational Stress Inventory-Revised Edition. RESULTS: Among the 910 female workers,14. 9%( 136/910) showed medium or higher scale on occupational role level,20. 1%( 183/910) showed medium or higher scale on occupational stress level,and 21. 4%( 195/910) showed medium or higher scale on personal resources lack. Multivariate logistic regression analysis indicated that the risk of occupational stress was high in single female workers and/or those exposed to occupational hazards( P < 0. 01). The higher the occupational role level,the higher risk of occupational stress( P < 0. 01). The less personal resources,the higher risk of occupational stress( P < 0. 01).CONCLUSION: Some female workers in labor-intensive enterprises showed medium or higher occupational stress level. The main influencing factors of occupational stress are marital status,exposure to occupational hazards,occupational role and personal resources.
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OBJECTIVE: To explore the changes of the serum immune cytokines in medical radiation workers exposure to low dose ionizing radiation. METHODS: Totally 244 medical professionals working with radiation(61 diagnosis radiology,51 nuclear medicine,74 radio therapeutics and 58 interventional radiology) from 7 hospitals of Guangdong Province were selected as study subjects by using the typical sampling method; 51 administration workers who did not expose to radiation were selected as control group. The radiation dose of these individuals was monitored by thermoluminescent measurement instrument for one year. Venous blood was collected and the levels of interferon γ(IFN-γ),interleukin 10(IL-10),transforming growth factor-β1(TGF-β1) in serum were examined by enzyme-linked immuno sorbent assay. RESULTS: The maximum annual average dose of radiation per person of the medical radiation workers was 0. 41 mSv/a. It was smaller than the occupational exposure limit(20. 00 mSv/a). The annual average dose of radiation per person in the group of nuclear medicine was significantly higher than those of diagnosis radiology,radio therapeutics and interventional radiology(P <0. 01). Among the male staffs,the expression of IL-10 in the diagnosis radiology group,radio therapeutics group and interventional radiology group was lower than that in the control group(P < 0. 05); the expression of IL-10 in radio therapeutics group was lower than those in nuclear medicine group and interventional radiology group(P < 0. 05); the ratio of IFN-γ/IL-10 in radio therapeutics group was higher than those in diagnosis radiology group,nuclear medicine group,interventional radiology group and control group(P < 0. 05). These individuals were divided into 3 different dose group(0. 03-,0. 06-and > 0. 15 m Sv/a) based on their average radiation dose. The expression of IL-10 in male staffs of these3 dose groups was lower than that of the male control group(P < 0. 05). CONCLUSION: Long-term low dose ionizing radiation may restrain the expression level of IL-10 in the male staffs.
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Objective To investigate the effects of low dose radiation on the level of oxidative damage and antioxidant in population of high background radiation area of Guangdong.Methods A total of 48 male residents who lived in high background radiation area(HBRA) of Guangdong province and 48 male residents who lived in neighboring Enping control area were chosen as the objectives and control respectively.The peripheral venous blood of two groups was collected,and then the levels of 8-OHdG and TrxR were determined by enzyme linked immunosorbent assay (ELISA).Results Compared with the CA group [(315.39 ± 100.59) ng/ml],the level of 8-OHdG [(272.64 ± 96.85) ng/ml] decreased significantly in HBRA (t =2.121,P ＜0.05).Compared with the CA group [(0.467 ±0.056) ng/ml],the level of TrxR [(0.496 ± 0.044) ng/ml] increased significantly in HBRA (t =-2.823,P ＜ 0.05).The results of multiple linear regression analysis demonstrated that the chronic exposure to low dose of radiation had significant effects on the expression level of 8-OHdG and TrxR (t =-2.327,2.367,P ＜ 0.05) after adjustment for confounding factors such as age,drinking,tea drinking,smoking,medical exposure and stressful events.Conclusions Chronic exposure to low dose radiation may decrease the level of oxidative and enhance the level of antioxidant.