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background The lead isotope ratios (LIR) differ among different sourced samples. Previous domestic and oversea studies on source tracing by LIR in human blood or urine mainly focused on the comparison of blood or urine samples from the same or different individuals, while few comparisons between biological and environmental samples, and the reported relative standard deviations (RSDs) of the main LIR (207/206Pb and 208/206Pb) fluctuate widely from 0.3% to 1%. Objective To optimize inductively coupled plasma mass spectrometry (ICP-MS), obtain a better RSD, and determine LIRs of human blood, urine, and related environmental samples. Methods The ICP-MS was optimized for operating conditions and parameters according to the sensitivity and RSD of LIR. The study subjects were 40 lead-exposed workers in a lead-acid battery factory and 2 lead poisoned children in a hospital. The samples included 40 blood and 40 urine samples from the workers before shift, 4 dust samples and 2 water samples in the workplace on the same day before shift, 2 blood and 3 urine samples from the children before hospital admission due to lead-poisoning, and 4 urine samples after medical treatment. After heating and acid digestion, the LIR (207/206Pb and 208/206Pb) of biological and environmental samples were determined by the optimized ICP-MS method. t-test and two-dimensional traceability graphics were adopted to analyze the detection results. Results The calibrated RSDs of the LIR (207/206Pb and 208/206Pb) of lead isotope standard solution were 0.11% and 0.08% respectively, and the NIST-SRM-981 actual values were 0.91531±0.00097 and 2.1670±0.0017, respectively. When the total concentration of lead was greater than 5 μg·L−1, the RSD of each isotope ratio was stable gradually; when the total concentration of lead was between 10-80 μg·L−1, the RSD was below 0.20%. There were statistically significant differences in the blood and urine LIR (207/206Pb and 208/206Pb) of the lead-exposed workers (t=5.831, P<0.001; t=21.021, P<0.001), the LIR (207/206Pb and 208/206Pb) between workplace dust samples and workers’ urine samples (t=−6.879, P=0.038; t=12.521, P<0.001), and the 208/206Pb between workplace dust samples and workers’ blood samples (t=−10.46, P<0.001), except the 207/206Pb between workplace dust samples and workers’ blood samples (t=−0.12, P=0.912). In the patients afflicted with lead poisoning, the projection points of LIR of blood and urine samples from the same individual were not at the same level in the two-dimensional model, nor was the LIR of urine samples before and after medical treatment of the same individual. Conclusion The optimized ICP-MS can control the RSD of main LIR (207/206Pb and 208/206Pb) below 0.20%. There are differences in the LIR distributions of different samples.
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Background The operation mode of automobile manufacturing industry (AMI) makes workers have different degrees of occupational stress and burnout, which may lead to negative emotions and depressive symptoms. Objective To study the relationship between occupational stress, job burnout, and depressive symptoms in AMI workers. Methods In this study, 1300 workers from a Guangzhou AMI company were selected as subjects by cluster random sampling method. Occupational stress, job burnout, and depressive symptoms of the workers were assessed by using the Effort-Reward Imbalance (ERI) questionnaire, the Maslach Burnout Inventory general survey questionnaire, and the Patient Health Questionnaire-9, respectively. Hierarchical regression was used to analyze the effects of occupational stress and job burnout on depressive symptoms in AMI workers. Mediating effect model was used to analyze the mediating effect of job burnout on the relationship between occupational stress and depressive symptoms. Results There were 1300 questionnaires distributed, 1228 valid questionnaires collected, with a 94.5% recovery rate. The ERI ratio of 1228 AMI workers was 1.06±0.72, and the positive rate of occupational stress was 37.3% (458/1228). The score of job burnout was 2.18±1.37, and the positive rate of job burnout was 62.6% (769/1228). The score of depressive symptoms was 10.27±6.42, and the positive rate of depressive symptoms was 47.1% (578/1228). The dimensional scores of effort and over-commitment in occupational stress as well as emotional exhaustion and depersonalization in job burnout of AMI workers were positively correlated with the depressive symptom scores (rs=0.415, 0.571, 0.573, 0.593, P＜0.05). The dimensional scores of reward and personal achievement were negatively correlated (rs=−0.454, −0.339, P＜0.05). The percentages of variance in depressive symptoms score explained by occupational stress and job burnout were 26.7% and 16.6%, respectively. Job burnout had a partial mediating effect between the three dimensions of occupational stress and depressive symptoms, and the mediating effect values were −0.2832 (95%CI: −0.3250– −0.2434), 0.3553 (95%CI: 0.3071–0.4041), and 0.4193 (95%CI: 0.3681–0.4725), respectively. Conclusion AMI workers' occupational stress affects job burnout, but also indirectly affects depressive symptoms. Job burnout partially mediates the association between occupational stress and depressive symptoms. Reducing occupational stress and burnout levels of AMI workers may alleviate depressive symptoms.
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Objective To explore the safety and feasibility of application of nalbuphine in uterine artery embolization. Methods We selected 70 cases of gynecologic fibroids receiving interventional surgery from January 2015 to October 2016 in our hospital.According to random number table,they were divided into either experimental group or control group,with 35 cases in each group.After selective uterine artery embolization,conventional intravenous analgesia pump was used to relieve pain.The experimental group was given nalbuphine 1 mg/kg and flurbiprofen 100 mg,and the control group was given sufentanil 2 μg/kg and flurbiprofen 100 mg.The visual analogue scale(VAS), nausea and vomiting, respiratory depression and other complications were observed in both groups after operation at 2,6,12,24 and 48 h. Results There were no significant differences between two groups at each time point after surgery in VAS scores[2 h:(4.2 ±0.7)points vs.(4.0 ±0.5)points,t=1.375,P=0.174;6 h:(3.5 ±0.4)points vs.(3.3 ±0.6)points,t=1.641,P=0.105;12 h:(3.0 ±0.7)points vs.(2.8 ±0.5)points, t=1.375, P=0.174;24 h:(2.8 ±0.5)points vs.(2.6 ±0.6)points,t=1.515,P=0.134].At 48 h after operation,the VAS score was significantly higher in the control group than that in the experimental group[(2.3 ±0.3)points vs.(2.1 ±0.4)points, t=2.366, P=0.021].The incidence of nausea in the experimental group was lower than that in the control group(22.9%vs.2.9%,χ2=4.590,P=0.032). Conclusion Use of nalbuphine for analgesia after uterine artery embolization has good analgesic results and reduces the incidence of nausea and vomiting after operation.
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<p><b>OBJECTIVE</b>To investigate noise hazard and its influence on hearing loss in workers in the automotive component manufacturing industry.</p><p><b>METHODS</b>Noise level in the workplace of automotive component manufacturing enterprises was measured and hearing examination was performed for workers to analyze the features and exposure levels of noise in each process, as well as the influence on hearing loss in workers.</p><p><b>RESULTS</b>In the manufacturing processes for different products in this industry, the manufacturing processes of automobile hub and suspension and steering systems had the highest degrees of noise hazard, with over-standard rates of 79.8% and 57.1%, respectively. In the different technical processes for automotive component manufacturing, punching and casting had the highest degrees of noise hazard, with over-standard rates of 65.0% and 50%, respectively. The workers engaged in the automotive air conditioning system had the highest rate of abnormal hearing ability (up to 3.1%).</p><p><b>CONCLUSION</b>In the automotive component manufacturing industry, noise hazard exceeds the standard seriously. Although the rate of abnormal hearing is lower than the average value of the automobile manufacturing industry in China, this rate tends to increase gradually. Enough emphasis should be placed on the noise hazard in this industry.</p>
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Humans , Automobiles , China , Hearing Loss, Noise-Induced , Epidemiology , Hearing Tests , Manufacturing Industry , Noise, Occupational , Occupational Exposure , Occupations , WorkplaceABSTRACT
<p><b>OBJECTIVE</b>To identify the occupational hazard factors in an accumulator factory, to analyze the status of internal and external lead exposure and evaluate the impact of lead exposure on the health of workers in the accumulator industry, and to provide a theoretical basis for improved lead exposure criteria and technical support for the control of lead contamination in the accumulator industry.</p><p><b>METHODS</b>An on-site investigation was carried out to monitor and evaluate the lead fume and dust in the workplaces of an accumulator factory, and occupational health examination was performed in all workers.</p><p><b>RESULTS</b>The occupational hazard safeguards in the accumulator factory were unadvanced. The contamination of lead fume and dust was serious. The abnormal rate of blood lead was up to 79.80%, and many workers developed anemia and mild peripheral nerve disease.</p><p><b>CONCLUSION</b>Lead contamination is serious in the accumulator factory, leading to poor health of workers. It is essential to take effective control measures, improve the working environment, provide occupational health education, increase workers' self-protection awareness, and periodically conduct occupational hazard monitoring and health surveillance. The government must reinforce occupational health supervision of such enterprises.</p>