ABSTRACT
@#<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.
ABSTRACT
Background The thyroid gland is one of the organs sensitive to ionizing radiation, and there are few studies on the effects of long-term exposure to low doses of ionizing radiation on the thyroid gland of radiation workers. Objective To investigate thyroid abnormalities in workers in medical radiology departments in Guangdong Province and to identify potential influencing factors of thyroid abnormalities. Methods A total of 1657 radiation workers from 48 hospitals in Guangdong Province were selected as survey subjects using convenience sampling, and their personal dose monitoring results and health examination information were retrospectively analyzed to determine the factors affecting thyroid abnormalities. Results The M (P25, P75) of thyroid absorbed dose (DT) was 1.55 (0.65, 3.96) mGy in the 1657 investigated workers. The attribute-specific medians of DT were 1.29, 1.38, 1.99, and 3.51 mGy for departments of diagnostic radiology, interventional radiology, radiotherapy, and nuclear medicine, respectively; and 1.10, 1.55, and 1.80 mGy for job titles of nurse, technician, and physician, respectively. Differences in DT by gender, age, years of radiological work, age of radiation exposure onset, occupational category, and job title were statistically significant (Z=−6.35, H=708.52, 918.20, 31.19, 95.64, 39.28, P<0.05). The positive rate of thyroid abnormalities in investigated workers was 46.53% (771/1657). Among them, the positive rate of abnormal thyroid function was 22.87% (379/1657), that of abnormal thyroid morphology was 33.98% (563/1657), and that of thyroid nodule was 26.55% (440/1657). The differences in thyroid abnormality rates by gender, age, years of radiation work, age of radiation exposure onset, DT, and job title of radiation workers were statistically significant (χ2=51.89, 49.64, 20.54, 18.29, 12.07, 16.16, P<0.05). The differences in abnormal thyroid function positive rate by gender, age of radiation exposure onset, and job title were statistically significant (χ2=26.21, 6.21, 8.32, P<0.05). The differences in the positive rates of abnormal thyroid morphology and nodules were statistically significant by gender, age, years of radiological work, age of radiation exposure onset, DT, and job title (abnormal thyroid morphology, χ2=40.24, 64.17, 37.63, 15.17, 19.28, 15.05; nodules, χ2=31.41, 77.98, 42.11, 19.16, 21.70, 13.52, P<0.05). The positive rates of thyroid abnormality, thyroid morphology abnormality, and nodules all showed a linear increasing trend with increasing age, years of radiation work, and age of radiation exposure onset (P<0.05). The results of logistic regression analysis indicated that the factors influencing thyroid abnormalities were female (OR=2.17, 95%CI: 1.72-2.74), increased years of radiological work (OR=1.04, 95%CI: 1.03-1.06), onset of radiation exposure in age groups of 30-34 and ≥35 years (OR=1.63, 95%CI: 1.12-2.37; OR=2.58, 95%CI: 1.74-3.29), and working in department of diagnostic radiology (OR=1.40, 95%CI: 1.07-1.84). Conclusion Long-term exposure to low doses of ionizing radiation has an effect on thyroid abnormalities in medical radiation workers. Among them, being female, physicians, and working in department of diagnostic radiology are at a higher risk of abnormal thyroid function; being female, increased years of radiation work, and radiation exposure onset at age ≥30 years are associated with a higher risk of reporting abnormal thyroid morphology.
ABSTRACT
Background Radiation-induced liver damage is a major complication for primary liver cancer and other upper abdominal tumors during radiation therapy. The early biological effects of radiation-induced liver damage at different doses of radiation and its mechanisms of action have not yet been elucidated. Objective To establish X-ray-induced radioactive mouse liver damage model and explore the level of oxidative stress and its correlation with nuclear factor-κB (NF-κB) and transforming growth factor-β1 (TGF-β1). Methods A total of 24 male C57BL/6J mice aged 6 weeks were randomly divided into 4 groups (control, 0.8 Gy, 1.6 Gy, and 4 Gy), with 6 mice in each group. X-rays irradiated the whole body of mice singly in each dose group. At 24 h after radiation, histopathological changes in mouse liver were evaluated; peripheral blood cell count, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, as well as liver tissue superoxide dismutase (SOD) activity, malondialdehyde (MDA) level, reduced glutathione (GSH) level, and 8-hydroxy-2′-deoxyguanosine (8-OHdG) level were measured; real-time fluorescence quantitative PCR was used to detect liver tissue NF-κB p65 and TGF-β1 mRNA expression levels; the correlations of oxidative stress indicators with NF-κB p65 and TGF-β1 mRNA expression levels were analyzed by Pearson correlation. Results Compared with the control group, at 24 h after different doses of X-ray radiation, early injury-related histopathological changes were observed in liver, and the serum levels of AST and ALT were significantly increased in the 4 Gy group (P<0.05); the numbers of peripheral blood leukocytes and lymphocytes were decreased in the radiation exposure groups (P<0.05), showing a decreasing trend with increasing radiation doses; the levels of liver oxidative stress indicators (MDA, SOD, and GSH) in exposed mice were significantly increased (P<0.05), showing an increasing trend with increasing radiation doses. The liver 8-OHdG were significantly increased in the 1.6 Gy and 4 Gy groups compared with the control and the 0.8 Gy groups, respectively (P<0.05). The NF-κB p65 and TGF-β1 mRNA expression levels in the liver of mice were significantly increased in the 1.6 Gy and 4 Gy groups compared with the control group (P<0.05). The TGF-β1 mRNA expression level also exhibited an increasing trend with increasing radiation doses. The results of correlation analysis showed that the levels of MDA, SOD, GSH, and 8-OHdG in liver tissues were significantly and positively correlated with the expression levels of NF-κB p65 and TGF-β1 mRNA (P<0.05). Conclusion X-rays of various doses can affect the degree of liver injury, peripheral blood cell count, serum levels of AST and ALT, and liver oxidative stress levels in mice. The level of oxidative stress induced by X-ray is positively correlated with NF-κB and TGF-β1 in liver tissues, and it may participate in the process of radiation-induced liver injury.
ABSTRACT
【Objective】 To explore the effects of Ligusticum Chuanxiong extract on MPP+-induced SH-SY5Y cell damage and Parkinson’s syndrome. 【Methods】 1-methyl-4phenylpyridine ion (MPP+) interfered with SH-SY5Y to establish a cell model of elderly Parkinson’s syndrome (SH-SY5Y-MPP+). After intervention with Ligusticum Chuanxiong extract, cell proliferation and apoptosis as well as miR-23a-3p and SNCA expressions were detected. In addition, the changes of SH-SY5Y-MPP+ after regulating the expression of miR-23a-3p and SNCA were observed, and the relationship between miR-23a-3p and SNCA was verified by dual luciferase reporter. 【Results】 The cell proliferation capacity of SH-SY5y-MPP+ was significantly lower than that of SH-SY5Y, while the apoptosis rate was higher than that of SH-SY5Y (P<0.05). Under the intervention of Ligusticum Chuanxiong extract, the proliferation ability of SH-SY5Y-MPP+, and Bcl-2 and SNCA protein increased, the apoptosis rate, miR-23a-3p, and Bax proteins decreased (P<0.05). Both silencing miR-23a-3p and increasing SNCA could promote the proliferation of SH-SY5Y-MPP+ and inhibit apoptosis, while increasing miR-23a-3p and silencing SNCA were the opposite (P<0.05). The online target gene prediction website found that miR-23a-3p and SNCA had complementary sites that could bind, and the dual luciferase reporter enzyme showed that the firefly activity of SNCA-wt was significantly inhibited after the miR-23a-3p mimic sequence was transfected (P<0.05). After increasing miR-23a-3p, the expression of SNCA protein in SH-SY5Y-MPP+ decreased, while silencing miR-23a-3p was the opposite (P<0.05). Rescue experiments showed that the intervention effect of Ligusticum Chuanxiong extract on SH-SY5Y-MPP+ was completely reversed by increasing miR-23a-3p or silent SNCA (P>0.05); the effect of increasing miR-23a-3p on SH-SY5Y-MPP+ increased SNCA reversion (P>0.05). 【Conclusion】 Ligusticum Chuanxiong extract can affect the biological behavior changes of SH-SY5Y induced by MPP+ by regulating the miR-23a-3p/SNCA axis, which may be a new direction for the treatment of elderly Parkinson’s syndrome in the future.
ABSTRACT
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.
ABSTRACT
Objective:To analyze the serum lipid levels, and its influencing factors, of male residents around an uranium mine in order to provide a scientific basis for health risk assessment for such residents.Methods:With such a mine as the center, the surveyed subjects were divided into four groups as within 5, 10, 15 and 20 km of this mine, respectively. These male residents living around the mine were randomly selected as subjects. A health questionnaire survey was conducted among the subjects. The indicator such as height, weight and blood pressure were measured by means of the standard method. Peripheral venous blood was extracted from the subjects, and their venous blood glucose and serum lipid were detected. The levels of serum lipid and detectable rates of abnormal serum lipid were analyzed by using univariate analysis, and multivariate logistic regression analysis was used to analyze the influencing factors of dyslipidemia.Results:A total of 867 males at age 40 to 69 was included in the vicinity of the mine. The mean levels ( ± s) of TC, TG, LDL-C, and HDL-C were (5.46±1.11), (1.92±1.64), (3.19±1.02), and (1.39±0.43) mmol/L, respectively. 384 subjects with dyslipidemia were totally detected in the residents, and the detection rate was 44.29% (384/867). Of the residents with dyslipidemia, the majority was abnormal in two lipid related indexes (45.57%, 175/384). Univariate analysis result showed that there was statistically significant difference in TG level in different distance groups ( F=3.34, P<0.05). There were statistically significant differences in the abnormal detection rates of TG and HDL-C in subjects in different distance groups ( χ2=9.52, 10.18, P<0.05). The detection rates of dyslipidemia were significantly different in the groups of BMI, blood pressure and blood glucose ( χ2=45.91, 32.31, 11.42, P<0.05). Multivariate logistic regression analysis showed that excluding marital status and degree of education, the BMI, blood pressure and blood glucose all had an impact on dyslipidemia. The residents with overweight ( OR=2.08, 95% CI: 1.52-2.86) and obeseness ( OR=2.88, 95% CI: 1.58-5.24) had a higher risk for dyslipidemia than those with normal weight. The risks for dyslipidemia in the residents with hypertension ( OR=1.94, 95% CI: 1.45-2.60) and hyperglycemia ( OR= 2.17, 95% CI: 1.27-3.69) were higher than those with normal blood pressure and blood glucose, respectively. Conclusions:The detection rate of dyslipidemia is higher in male residents around the mine. The BMI, alcohol consumption, blood pressure, blood glucose and distance from the mine are influencing dyslipidemia and other relevant indexes. Overweight is an independent risk factor for dyslipidemia and its components. The distances from uranium mine has no significant effect on the dyslipidemia of male residents.
ABSTRACT
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.
ABSTRACT
OBJECTIVE: To explore the influencing factors of occupational stress from occupational hazards in employees of a power grid enterprise. METHODS: A total of 972 employees from 3 substations and 1 power dispatch center of a power grid enterprise were selected as research subjects by the cluster sampling method. The Chinese version of the Job Content Questionnaire was used to evaluate the occupational stress using the job demand control(JDC) model. The influence of occupational hazards on occupational stress was analyzed. RESULTS: The median, the 25 th and 75 th percentile scores [M(P_(25), P_(75))] of the 972 research subjects on job demand, job control, and social support dimensions of JDC model occupational stress were 14(12, 15), 25(23, 26), 24(23, 24), respectively. The M(P_(25), P_(75)) of the demand/control(D/C) ratio was 0.99(0.89, 1.13). The incidence of occupational stress was 48.4%(470/972) by the JDC model. The job demand dimension scores, D/C ratios, and incidence of occupational stress by JDC model were higher in employees exposed to electromagnetic radiation, high temperature, high altitude, and visual display terminal(VDT) than in those employees not exposed to the above factors(all P<0.05). The results of multivariate logistic regression analysis showed that the risk of occupational stress increased in those employees exposed to high temperature, high altitude and VDT(all P<0.05) after excluding the influence of confounding factors such as age, length of service, monthly income and exercise. The odds ratio and 95% confidence intervals were 1.91(1.43-2.54) and 1.67(1.26-2.21), respectively. CONCLUSION: The level of occupational stress among employees in power grid enterprise is relatively high by JDC model. High-temperature, high-altitude and VDT operation are the main risk factors of occupational stress by JDC model.
ABSTRACT
OBJECTIVE: To explore the influencing factors of depressive symptom of employees in a mould-producing enterprises using two occupational stress models. METHODS: A total of 457 employees in a mould-producing enterprise were selected as study subjects using cluster sampling method. The Center for Epidemiological Study-Depression Scale, the Chinese version of Job Demand Content Questionnaire and the Effort-Reward Imbalance Questionnaire were used to investigate the level of depressive symptom and occupational stress by the job demand control(JDC) model and effort reward imbalance(ERI) model. RESULTS: Among the 457 employees, the median score of depressive symptom was 11.00, the detection rate of depressive symptom in the subjects was 23.4%(107/457). The incidence of occupational stress by the JDC and ERI models was 78.3%(358/457) and 62.6%(286/457), respectively. The rate of depressive symptom was statistically higher in the high occupational stress group than that of the low occupational stress group by the ERI model(26.6% vs 18.1%, P<0.05). The multivariate logistic regression analysis showed that both marital status and monthly income were influencing factors of depressive symptom by the JDC model(P<0.05). The marital status, monthly income and occupational stress were influencing factors of depressive symptom by the ERI model(P<0.05). The risk of depressive symptom was statistically higher in the high occupational stress group than that of the low occupational stress group(P<0.05). CONCLUSION: Employees in mould-producing enterprise have some depressive symptom. The marital status, monthly income and occupational stress by the ERI model are the main influencing factors of depressive symptom.
ABSTRACT
OBJECTIVE: To discuss the applicability of 3 risk assessment methods to evaluate the occupational health risk of benzene and its analogues in the workplace of an aircraft maintenance enterprise. METHODS: The workshops of compound material,structural and electromechanical involved in exposure of benzene and its analogues in an aircraft maintenance enterprise were chosen as study subjects. The optimal indicator system of risk assessment on occupational chemical hazards( hereinafter referred to as“optimal indicator system”),the Singapore semi-quantitative risk assessment model and risk index method were used to classify the benzene hazards of 5 operating posts in 3 workshops. The risk stratification results of the 3 assessment methods were compared. RESULTS: The results of optimal indicator system for benzene risk rating was mild risk in all workplaces. The risk classifications for toluene and xylene were light risk. The risk classifications of Singapore semi-quantitative risk assessment model for benzene,toluene and xylene were all low risk in all workplaces. The risk classifications of risk index method for benzene were all moderate risk in all workplaces. The risk classifications for toluene were harmless in all workplaces. The risk classifications for xylene were mild risk in all workplaces. CONCLUSION: There are differences among the evaluation results of the 3 risk assessment methods. The optimal indicator system could be more suitable for occupational health assessment of benzene and its analogues in aircraft maintenance industries.
ABSTRACT
OBJECTIVE: To establish the occupational exposure limits for methyl t-butyl ether(MTBE) in the air of workplace in China. METHODS: According to the GBZ/T 210.1-2008 Guide for Establishing Occupational Health Standards--Part 1: Occupational Exposure Limits for Airborne Chemicals in the Workplace, we collected and analyzed data on physical and chemical properties, toxicology, occupational epidemiology and foreign occupational exposure limits related to MTBE by literature search. A total of 180 occupational workers exposed to MTBE were selected as exposure group, and 155 workers and administrative logistics personnel without exposure to MTBE were selected as the control group. Occupational hygiene investigation and occupational physical examination were carried out. We deduced the occupational exposure limits for MTBE in workplace air in China by combining literature data. RESULTS: The time-weighted average(TWA) of MTBE in the workplace air developed by the United States of America and Britain is 180.00 mg/m~3. The short-term exposure limit(STEL) of MTBE in the workplace air developed by Australia and New Zealand is 270.00 mg/m~3. The concentration of TWA(C_(TWA)) of MTBE in the exposure group was less than 0.08-4.90 mg/m~3. The concentration of short term exposure was less than 0.10-14.28 mg/m~3, and the C_(TWA) was less than 0.02-83.66 mg/m~3, in parts of workplaces. There was no statistically significant difference on the self-conscious discomfort and the abnormality in physical examination between these two groups(P>0.05). CONCLUSION: It's recommended that the permissible concentration-TWA of MTBE should be set at 180.00 mg/m~3, and the permissible concentration-STEL should be set at 270.00 mg/m~3 in China.
ABSTRACT
OBJECTIVE: To analyze the effects of long term exposure to power frequency electromagnetic fields( PFEMF) on apoptotic rates of peripheral blood T and B lymphocytes in workers of transformer substation. METHODS: A random number table method was used to select 73 workers with long-term exposure to PFEMF as exposure group and 70 non-exposure workers( administrative and logistics staffs) were selected as control group from 10 transformer substations in a province.The peripheral venous blood of workers in these two groups was collected,and the apoptosis of T and B lymphocytes were detected and analyzed by flow cytometry. RESULTS: The apoptosis rates of T and B lymphocyte between the exposure and non-exposure groups showed no statistical difference( median: 1. 555% vs 0. 790%,0. 020% vs 0. 030%,P > 0. 05).The multivariate linear regression analysis showed that both the PFEMF exposure and length of service had no significant effects on the apoptosis rates of T lymphocyte and B lymphocyte after adjusting confounding factors such as gender,age,alcohol drinking,smoking,medication history,medical radiation exposure and stressful events( P > 0. 05). CONCLUSION: Long-term exposure to PFEMF has no effects on apoptosis of peripheral blood T and B lymphocytes in workers of transformer substation.
ABSTRACT
Objective To analyze the related influencing factors of progressive ischemic stroke, and to investigate the value of serum markers for prediction of progressive ischemic stroke. Methods Three hundred and six patients with acute cerebral infarction were divided into progressive ischemic stroke (PIS) group (n=91) and non-progressive ischemic stroke (NPIS) group (n=215). Data of gender, age, past medical history, personal history and serum markers were collected and compared in two groups. Binary Logistic regression was used to analyze the influencing factors of PIS. The receiver operating characteristic (ROC) curves of neutrophils to lymphocytes ratio (NLR), fibrinogen and fasting blood glucose were analyzed in two groups. Results Positive rates of hypertension history, diabetes history, hypercholesterolemia history, incidence of large artery atherosclerotic (LAA) stroke were significantly higher in PIS group than those in NPIS group ( P<0.05). The levels of neutrophils, NLR, fibrinogen and fasting blood glucose were significantly higher, but the level of lymphocytes was significantly lower in patients with PIS than those in patients with NPIS (P<0.05). Logistic regression analysis confirmed that diabetes, LAA stroke, NLR, fibrinogen and fasting blood glucose were independent risk factors for the PIS ( P<0.05). The areas under ROC curve by NLR, fibrinogen and fasting blood glucose were 0.777, 0.560 and 0.574, respectively. The sensitivities of NLR, fibrinogen and fasting blood glucose were 72.5%, 59.8%and 47.3%, respectively;and the specificities were 76.7%, 51.2% and 69.8%, respectively. Conclusion The occurrence of PIS is related with blood pressure, blood lipids, inflammatory cells in peripheral bolld, fibrinogen and fasting blood glucose. The level of NLR in peripheral blood can predict the occurrence of PIS, which can be used as an important reference index for early diagnosis of PIS.
ABSTRACT
Objective@#To apply and compare two risk assessment methods for occupational lead exposure risk classification in a lead-acid battery enterprise.@*Methods@#In April 2013, an occupational health survey was carried out in a lead-acid battery enterprise. Lead smoke and lead dust were tested in the workplace. The risk assessment index system for occupational chemical hazards that was established and optimized by the research group (referred to as "optimized index system" ) , as well as the Singapore semi-quantitative risk assessment model, was used for occupational lead exposure risk classification in the lead-acid battery enterprise. The two risk classification results were analyzed and compared.@*Results@#In the lead smoke risk classification results, the optimized index system classified the raw material group and foundry group workshops as Class I hazardous and the assembling group workshop as Class II hazardous. The Singapore semi-quantitative risk assessment model classified the raw material group workshop as high risk and foundry group and assembling group workshops as extremely high risk. In the lead dust risk classification results, the optimized index system classified the raw material group workshop as Class I hazardous, while the plate painting group, plate cutting group, and assembling group workshops were classified as Class II hazardous. The Singapore semi-quantitative risk assessment model classified the raw material group workshop as medium risk, the plate painting group and plate cutting group workshops as high risk, and the assembling group workshop as extremely high risk.@*Conclusion@#There are some differences in risk assessment of occupational lead exposure between the two risk assessment methods. The optimized index system is comparably more reasonable and feasible, and is highly operable.
ABSTRACT
Objective To study the relationship between serum uric acid (UA) level and cerebrovascular stenosis in acute ischemic stroke (AIS) patients.Methods Five hundred and thirteen patients with AIS or old IS admitted to our hospital from April 2014 to April 2016 were divided into primary IS group (n=236),recurrent IS group (n=136),and old IS group (n=141).Venous blood samples were taken on admission for biochemical testing.The patients were further divided into serum UA≤255 μmol/L group (n=128),serum UA=256-312μmol/L group (n=129),serum UA=313-371 μmol/L group (n=129),and serum UA＞371 μmol/L group (n=127).Their cerebrovascular stenosis was assessed by CT angiography or magnetic resonance angiography after admission.Results The severity of cerebrovascular stenosis,hypertension,diabetes and hyperlipidemia was significantly different in primary IS group,recurrent IS group and old IS group (27.5％ vs 33.8％ vs 12.8％、24.2％ vs 28.7％ vs 46.8％、61.9％ vs 49.3％ vs 40.4％、71.6％ vs 61.8％ vs 46.8％,P=0.000).Logistic regression analysis showed that serum UA≤ 255 μmol/L was an independent risk factor for cerebrovascular stenosis (OR =2.787,95 ％CI:2.209-3.365,P=0.001).The risk of cerebrovascular stenosis decreased gradually with the elevated serum UA level.Conclusion Serum UA level is not directly related with recurrent IS.Low serum UA level is a risk factor for cerebrovascular stenosis in AIS.
ABSTRACT
OBJECTIVE: To screen genetic polymorphisms in the 5'-flank region of 8-hydroxyguanine DNA glycosylase( hOGG1) gene and analyze the characteristics of their genetic distribution in Han population of radon exposure area in Guangdong Province. METHODS: A simple random sampling method was used to select 60 subjects as radon exposure population. The genomic DNA samples were extracted from peripheral blood. The single nucleotide at-1721 nt-+ 164 nt locus of hOGG1 were screened using polymerase chain reaction( PCR) amplification,purification and direct sequencing for polymorphisms. Genetic characteristics of single nucleotide polymorphisms( SNP) in the study population were analyzed and compared with different populations reported in Hap Map data. RESULTS: The 5'-flank region of hOGG1 were amplified and sequenced in these 60 individuals( 120 chromosomes) of healthy Han Chinese in radon exposure area. Eight SNPs were identified by sequence alignment in the study population. Among them,there was 3 known polymorphisms and their minor allele frequencies( MAF) were-1493 G > A( 4. 2%),-834 G > C( 0. 8%) and-18 G > T( 3. 3%),respectively. The MAF of other 5 novel variations were-1455 G > A( 0. 8%),-1293 A > T( 23. 3%),-1187 C > A( 7. 5%),-337 C > A( 36. 7%) and-323 G > A( 0. 8%),respectively. The differences in the MAF distribution of-1493 G > A between the study population and the Hap Map-CEU were statistically significant( P < 0. 05). CONCLUSION: Eight SNPs and their genetic characteristics were screened and identified in the 5'-flank region of hOGG1 of Han Chinese population in radon exposure area. This result provides a basis for construction of polymorphism haplotypes and functional analysis for the target population.
ABSTRACT
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.
ABSTRACT
OBJECTIVE: To compare and analyze the risk rating for chemical hazards of aromatics complex in a petrochemical enterprise using two risk assessment methods. METHODS: Occupational hygiene investigation and chemical detection for workplaces of the construction project were made. The risk ratings were made in five workplaces including that of the aromatics extraction,disproportionation,isomerization,xylene fractionation and adsorptive fractionation. Two risk assessment methods were employed. They were the optimal indicator system of risk assessment on occupational chemical hazards( optimal indicator system) and the semi quantitative risk assessment model of Singapore. The results of risk rating generated by the two risk assessment methods were then compared and analyzed. RESULTS: Using the optimal indicator system,the risk rating of benzene was mild in the five workplaces; and the risk rating of methylbenzene and xylene was slight. However,using the semi quantitative risk assessment model of Singapore,the risk rating of benzene was extremely high in both the aromatics extraction and disproportionation workplaces; the risk rating was high in xylene fractionation,and was medium in the isomerization and adsorptive fractionation workplaces. The risk rating of methylbenzene was high in the aromatics extraction and disproportionation workplaces,and was low in the other three workplaces. The risk rating of xylene was low in the five workplaces. CONCLUSION: The optimal indicator system is more feasible,practical and objective for the assessment of chemical hazards. It is more suitable for risk assessment of occupational chemical hazards in our country.
ABSTRACT
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.