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Noise is a common occupational hazard in workplaces. Long-term exposure to high-intensity noise mainly causes occupational noise-induced hearing loss (ONIHL). The development of ONIHL is irreversible, and there is currently no cure. At present, risk assessment methods based on noise exposure intensities mainly include risk index assessment method, Engineering Professional Council assessment method in United Kingdom (EDC assessment method in UK), National Institute of Occupational Safety and Health assessment method in United State (NIOSH assessment method in US), and International Standardization Organization assessment method (ISO assessment method). However, the risk index assessment method is subjective and does not consider the effectiveness of workers wearing protective equipment. The EDC assessment method in UK defines ONIHL differently from China. The NIOSH assessment method in US and ISO assessment methods have population data sources that deviate from China, which can lead to bias in risk assessment. In the future, it is necessary to further carry out application research on the risk assessment of ONIHL in Chinese noise-exposed workers, compare the applicabilities of various assessment methods, conduct large-sample population epidemiological studies for verification, and fully utilize the risk-prediction function to prevent and control ONIHL.
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Background The converter stations of high-voltage direct current (HVDC) transmission lines generate special total electric fields. At present, few investigations have been conducted on total electric fields in the workplace of converter stations from an perspective of occupational health. Objective To understand the current situation of total electric field strength in the workplace of converter stations. Methods Using purposive sampling, a calibrated HDEM-1 direct current (DC) total electric field strength measurement system was used to measure the total electric fields of 12 converter stations serving 6 DC lines in Southeast and Southwest China according to the Measurement method for total electric field strength and ion current density of the converter stations and DC transmission lines (DL/T 1089—2008). The results were evaluated according to occupational exposure limits recommended by The limits of electromagnetic environment at ±800 kV UHV DC converter station (DL/T 275—2012), the American Conference of Governmental Industrial Hygienists (ACGIH), and the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Results A total of 615 check points were planned, the total electric field strength was 0.05-37.05 kV·m−1, and the median was 10.45 kV·m−1. The total electric field strength of 39 check points (6.3%) exceeded 25 kV·m−1 (the limits of ACGIH and ICNIRP), and the total electric field strength of 12 check points (2.0%) exceeded 30 kV·m−1 (the limit of DL/T 275—2012). There were statistically significant differences in the total electric field strength values and the proportions of exceeding 25 kV·m−1 between the neutral regions and the positive regions and between the neutral regions and the negative regions (P < 0.01). The proportion of total electric field strength exceeding 30 kV·m−1 in the negative regions was higher than that in the positive regions (P < 0.01). There were no significant differences in the total electric field strength of converter stations at different voltage levels and different altitudes (P > 0.05). There were no significant differences in the proportions of total electric field exceeding 25 kV·m−1 and exceeding 30 kV·m−1 in converter stations at different voltage levels and different altitudes (P > 0.05). Conclusion The total electric field in some workplace of converter stations exceeds selected limits. Converter station operators may be exposed to high-strength total electric field for a short time.
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Background Prolonged awkward postures during occupational activities can lead to excessive musculoskeletal load on the wrist of workers and symptoms such as wrist pain or discomfort. Objective To survey the prevalence of wrist pain among workers in 10 key industries and analyze its correlation with wrist working postures. Methods By using stratified cluster sampling method, workers from 10 key industries, such as footwear manufacturing industry, shipbuilding manufacturing industry, and automobile manufacturing industry, were selected from seven regions in North China, East China, Central China, South China, Southwest China, Northwest China, and Northeast China. The demographic information, wrist working postures, pain in wrist of the workers were collected through a cross-sectional survey. Pearson χ2 test was used to compare prevalence by selected factors, trend χ2 test for between group comparison, and unconditional logistic regression models for the association of wrist working postures with wrist pain. Results There were 64052 workers enrolled in this survey, and 56286 provided valid questionnaires (the effective rate was 87.8%). According to the survey, the prevalence of wrist pain was 23.3% (13112/56286), and the industries with higher prevalences were footwear manufacturing (27.1%, 1927/7106), automobile manufacturing (24.9%, 5378/21560), and shipbuilding and related equipment manufacturing (24.4%, 850/3488) industries. Finger pinching (OR=2.09, 95%CI: 1.95-2.24), frequent wrist bending (OR=2.03, 95%CI: 1.92-2.15), fixed wrist bending (OR=1.77, 95%CI: 1.69-1.85), wrist on hard edge (OR=1.34, 95%CI: 1.28-1.40), and arms over shoulders (OR=1.11, 95%CI: 1.05-1.17) increased the risk of reporting wrist pain. Conclusion Awkward postures are related to wrist pain among workers in selected 10 key industries. The related factors are wrist on hard edge, frequent wrist bending, finger pinching, fixed wrist bending, and arms over shoulders.
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Sepsis is currently the leading cause of death in the intensive care unit, and its survivors also experience long-term immunosuppression and high rates of recurrent infections. At present, the clinical treatment of sepsis is still based on antibiotics, intravenous rehydration, and vasopressors, and there is no targeted drug treatment. However, as the rate of antibiotic resistance continues to increase, immunotherapy is highly anticipated as a new treatment. Patients with sepsis are often accompanied by acute leukocyte immune dysfunction and immunosuppression, which may be an important risk factor for the increasing morbidity and mortality of patients. Targeted inhibition of specific cell surface inhibitory immune checkpoint receptors and ligands, such as programmed death receptor-1 (PD-1), programmed death-ligand 1 (PD-L1), and other targets, can improve the host’s resistance to infection. In this paper, the research progress of PD-1 and PD-L1 in the immune response to sepsis was summarized to provide a theoretical basis for their further application in the treatment of sepsis in the future.
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Objective: To analyze the current status of work-related musculoskeletal disorders (WMSDs), work fatigue and musculoskeletal pain in Chinese occupational population, and to study the relationship between work fatigue and musculoskeletal pain and WMSDs. Methods: A total of 66 961 employees from 323 enterprises in 15 key industries in China were selected as the study subjects using stratified cluster sampling method. The incidence of WMSDs in the past year was investigated using the Chinese version of the Musculoskeletal Disorders Questionnaire, and the work fatigue and musculoskeletal pain were investigated using Borg 6-20 Rating of Perceived Exertion Scale and visual analogue scale. The data were standardized using the age composition data of 18 to 60 years from the seventh national population census. Results: The standardized annual incidence of WMSDs was higher in the front-line workers than that in the administrative and other supportive staff (38.82% vs 36.30%). The detection rates of work fatigue and musculoskeletal pain in the study subjects were 44.54% and 63.08%, respectively. The result of S-curve fitting showed that the risk of WMSDs increased with the level of work fatigue (P<0.01). Among the front-line workers, the average of monthly fatigue frequency in the neck, shoulder, lower back, upper back, wrist/hand, foot and ankle, knee, leg, and elbow were higher in the group with WMSDs compared to those without WMSDs (all P<0.01). The pain degree of musculoskeletal pain was higher in all nine sites in the fatigued group than in the no-fatigue group (all P<0.01). The standardized detection rate of musculoskeletal pain was higher in the fatigued group than in the non-fatigued group (80.38% vs 25.71%). The work fatigue was moderate and positively correlated with musculoskeletal pain in all seven sites except the lower back and elbow, with Kendall Tau-b correlation coefficients ranging from 0.423 to 0.546 (all P<0.01). Conclusion: There is a good correlation between work fatigue and local musculoskeletal pain, work fatigue and WMSDs in Chinese occupational population. Implementing ergonomic interventions to control the development of work fatigue can be an effective measure for preventing WMSDs.
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Objective: To analyze the status of noise hazard in workplace of key industries in Guangdong Province. Methods: A total of 1 061 enterprises from 14 key industries in 21 prefecture-level cities in Guangdong Province were selected as the research subjects using stratified sampling method. The occupational health survey was carried out, and the noise intensity in the workplace was detected. Results: There were 12 606 workplaces and 5 570 work sites involved among 1 061 enterprises. The median and the 0-100th percentile value [M (P0-P100)] of noise intensity in workplace were 82.6 (46.5-112.6) dB(A), and 35.03% of the workplace exceeded the national noise intensity standard. The regions and industry with the highest rate of noise exceeded the national noise intensity standard in workplace were in the northern part of Guangdong and the stone processing industry respectively. The M (P0-P100) of noise intensity in the work sites was 83.7 (47.5-106.2) dB(A), and 36.00% of the work sites exceeded the national noise intensity standard. The regions and industry with the highest rate of noise exceeded the national noise intensity standard in work sites were in the Pearl River Delta region and the ferrous metal mining and dressing industry respectively. The rate of noise protection facilities setting was 66.45%, and the validity of personal protection was 61.73%. The occupational medical examination was performed in 73.24% of the research subjects, and 3.25% of the result was abnormal. The industry with the highest occupational medical examination rate was nonferrous metal smelting and rolling processing, and the industry with the highest abnormal rate of occupational medical examination was stone processing industry. Conclusion: Noise hazards in workplaces of key industries in Guangdong Province are relatively severe, necessitating strengthened supervision and management, noise control measures, and efforts to reduce noise exposure levels in workplaces and work sites.
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Objective To analyze the characteristics of work-related musculoskeletal disorders (WMSDs) among sonographers in Guangdong Province, and to explore the disease pattern of the cases. Methods A total of 512 sonographers from 31 hospitals in Guangdong Province were selected as the research subjects using stratified cluster sampling method. The prevalence of WMSDs in the past year was investigated using the Musculoskeletal Disorders Questionnaire, and the characteristics of WMSDs were analyzed. Latent class analysis was used to identify the disease pattern of WMSDs. Results The overall prevalence of WMSDs was 94.3%. The top five affected body parts were right shoulder, neck, right hand/wrist, lower back and right forearm/elbow, with the prevalence of 80.3%, 75.4%, 61.1%, 55.5% and 45.3%, respectively. The prevalence of WMSDs was higher on the right side for the shoulder, hand/wrist, forearm/elbow, hip/leg and knee compared with the left side (80.3% vs 31.3%, 61.1% vs 13.9%, 45.3% vs 10.0%, 17.4% vs 8.6%, 13.1% vs 8.4%, all P<0.05). The prevalence of WMSDs increased with work years, as well the prevalence of WMSDs in the top five affected body parts among the sonographers (all P<0.05). However, there were no statistical differences in prevalence of WMSDs between general hospitals and maternal and child health hospitals, tertiary hospitals and non-tertiary hospitals, Pearl River Delta hospitals and non-Pearl River Delta hospitals; there was also no statistical difference between different genders and age groups of the sonographers (all P>0.05). The best-fit latent disease pattern for sonographers WMSDs comprised three categories: symptom of neck-right shoulder, symptom of neck-lower back-right shoulder-right elbow-right hand/wrist, and symptom of multi-parts above the knees, with the latent probabilities of 0.438, 0.427 and 0.135, respectively. Conclusion The prevalence of WMSDs in sonographers is extremely high, with a dose-effect relationship with work years. The most common affected parts are neck, lower back and right shoulder, right hand/wrist, and right forearm/elbow. The prevalence of WMSDs in the right side of limb was higher than that in the left. WMSDs primarily occur in multiple parts simultaneously. The most common symptoms occur in the neck-right shoulder and neck-lower back-right shoulder-right elbow-right hand/wrist.
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Objective To investigate the level of finger systolic blood pressure (FSBP) in healthy young adults. Methods A total of 28 healthy young adults were selected as the study subjects by convenient sampling method. The FSBP of the study subjects was detected at 30 and 10 ℃, and the FSBP index (Fi) was calculated. Results The FSBP of the study subjects at 30 and 10 ℃ were (102.0±16.5) and (104.4±15.2) mmHg, respectively. The FSBP in male group at 30 and 10 ℃ was (99.6±18.6) and (107.2±17.0) mmHg, respectively. The FSBP in female group at 30 and 10 ℃ was (104.4±13.9) and (101.5±2.8) mmHg, respectively. The results of factorial analysis showed that the interaction between gender and temperature on FSBP was statistically significant (P<0.05). FSBP in male group was higher at 10 than 30 ℃ (P<0.05) and higher than female group at 10 ℃ (P<0.05). There was no statistical significance for the main effect of gender, temperature, finger, or the interaction effect of gender and finger, temperature and finger for FSBP (all P>0.05). The average Fi of the study subjects was (98.0±16.6)%, with males and females having the average Fi of (100.7±20.7) % and (95.2±10.6) % respectively. The results of factorial analysis of variance showed that there was no significant difference on Fi in the main effect gender and fingers or the interaction effect between them(all P>0.05). Conclusion The FSBP test could be used as a detection method for assessing peripheral microcirculation function in Chinese population. However, further research is needed to establish reference ranges and influencing factors.
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Objective:To investigate the effects of long-term high-fat diet on bone mineral density and intestinal flora in mice.Methods:Sixteen male C57BL/6 mice were randomly divided into control group (NC group) and high-fat group (HF group). After 24 weeks of high-fat feeding, biochemical indicators such as blood glucose and blood lipids were detected, bilateral femurs were taken and bone microstructure was analyzed with micro-computered tomography (micro-CT), and changes of intestinal microbial composition and proportion were revealed using 16S rDNA sequencing technology.Results:Compared with the control group, the serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in HF group were significantly increased. Micro-CT uncovered that the bone mineral density (Tb.BMD), bone volume fraction (BV/TV) and the number of trabecular bone (Tb.N) decreased, yet structural model index (SMI) and the trabecular fraction (Tb.Sp) increased in the HF group mice. The gut microbiota 16S rDNA sequence analysis showed that the proportion of Proteobacter was significantly increased and the proportions of pachycete, warty microbacterius, and actinomycete were reduced in HF group at the phyla level. The proportion of Bacteroidetes S24-7_norank in the NC group was significantly higher than that in the HF group, and the multilevel discriminant analysis of species differences (LEfSe) identified that the difference was significant, yet the proportion of Bacteroides, Pseudo-Prevotella, Desulfovibrio, Altobacter, and Helicobacter in the HF group were higher than those in the NC group, which were significant differences in Altobacter and Helicobacter at genus level.Conclusion:Long-term high-fat feeding can cause the destruction of femoral trabecular structure, decrease in the number of trabeculus bones, and bone mineral density in C57BL/6 mice. It also leads to significant changes in the composition and proportion of the intestinal flora.
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Background Hand arm vibration disease (HAVD) is one of the legal occupational diseases in China, and its pathogenesis is not clear. Operators exposed to electric vibration tools for a long time have an increased risk of HAVD. Objective To conduct a systematic evaluation of the effects of vibration operations on workers' upper limb nerves, blood vessels, and muscles. Methods Relevant studies on the effects of hand-transmitted vibration on HAVD were searched and collected from the China Knowledge Infrastructure, Wanfang, and PubMed databases, and the literature was published from January 1974 to April 2021. The quality of cohort and case-control studies was assessed by the Newcastle-Ottawa Scale (NOS), and the quality of cross-sectional studies was by the evaluation criteria recommended by the Agency for Healthcare Quality and Research (AHRQ). Statistical analyses of outcome indicators (OR) in the included literature were performed using RevMan 5.4.1 software, effect sizes in the literature on vibration-induced white finger and neurosensory impairment were combined using a random-effect model, those that included carpal tunnel syndrome were combined using a fixed-effect model, and subgroup and publication bias analyses were also performed. To explore sources of study heterogeneity, meta-regression was performed using Stata 16.0 software, and sensitivity analyses were performed on the included literature. Results A total of 716 papers were retrieved from the databases, and 18 articles were retrieved by manual searching. A total of 34 papers were included after excluding those not meeting the criteria. Of the papers, 11004, 7270, and 1722 subjects related to vibration-induced white finger, neurosensory impairment, and carpal tunnel syndrome, respectively. The results of meta-analysis showed that compared with the control group, the combined ORs of hand-transmitted vibration exposure were 4.25 (95%CI: 2.72−6.65) for vibration-induced white finger, 4.03 (95%CI: 2.46−6.61) for neurosensory impairment, and 2.44 (95%CI: 1.61−3.71) for carpal tunnel syndrome. Heterogeneity was identified in the original studies related to vibration-induced white finger (I2=81%, P < 0.001) and neurosensory impairment (I2=90%, P < 0.001), except carpal tunnel syndrome (I2=23%, P < 0.001). The results of sensitivity analysis showed that the combined effect sizes (ORs) were stable and reliable. The results of meta-regression showed that the factors contributing to high heterogeneity of combined vibration-induced white finger and neurosensory impairment were time of publication (t=−2.10, P=0.049) and working age (t=−2.40, P=0.032), respectively. Conclusion Hand-transmitted vibration is a risk factor for vibration-induced white finger, neurosensory impairment, and carpal tunnel syndrome in operators.
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Objectives@#This study examines the status of iodine intake and compares the characteristics (region and thyroid disease prevalence) according to the iodine-sourced food intake pattern in Chinese adults. @*Methods@#An online survey was conducted by enrolling 437 Chinese adults aged 18-65 years, living in three regions with different iodine nutritional statuses: Sichuan, Chongqing, and Guangdong. @*Results@#The prevalence of thyroid diseases in Sichuan, Chongqing, and Guangdong were 12.5%, 8.5%, and 2.8%, respectively. Conversely, the proportion of people who received thyroid disease-related examinations was a mere 37.5%. Among the subjects who underwent thyroid examination, the prevalence of thyroid disease in the three regions was 32.2%, 21.8%, and 8.0%, respectively. No differences were obtained in the total iodine intake by region, but the type of iodine source foods differed. Regardless of the region, the highest iodine content was obtained from seaweed. However, the iodine content from iodized salt and other foods differed significantly by region. Factor analysis revealed three food intake patterns according to the iodine food source. The study further determined regional differences and differences in the prevalence of thyroid disease according to food intake patterns. @*Conclusions@#High salt intake can also increase iodine intake, which is thought to have an effect on the occurrence of iodine-excess thyroid disease. Hence, efforts focused on improving salty eating habits need to be implemented.
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OBJECTIVE: To determine the prevalence and influencing factors of work-related musculoskeletal disorders(WMSDs) among workers in a shipyard. METHODS: A total of 496 workers in a large shipyard in Guangdong Province were selected as research subjects using the convenient sampling method. The Questionnaire of Musculoskeletal Disorders was used to investigate the prevalence of WMSDs in various regions of the body in the past year.Multivariate logistic regression was used to analyze the potential influencing factors of WMSDs in the frequently affected body parts. RESULTS: The prevalence of WMSDs was 70.2%(348/496). The prevalence rates of WMSDs in different body regions were: lower back/waist(43.1%), neck(29.4%), shoulder(29.0%), hand/wrist(25.4%), knee(22.4%), hip/leg(14.3%), ankle/foot(12.1%), upper back(11.3%) and elbow(9.3%). Multivariate logistic regression analysis results showed that increased risk of lower back/waist WMSDs occurred in workers who carry heavy objects>5.0 kg, who work in uncomfortable positions, who repeatedly perform the same work every day, and who repeatedly perform the same action using the lower limbs and ankles(P<0.05). Employees working ≤8 hours or more than 8 hours per day had higher risk of developing lower back/waist WMSDs compared with workers working 8-10 hours per day(P<0.05). CONCLUSION: The prevalence of WMSDs among workers in the shipyard is high.The lower back/waist WMSD is the most common one. The influencing factors include work organization and adverse ergonomic factors.
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OBJECTIVE: To investigate the effect of hand-transmitted vibration on the subjective symptoms of mine drilling workers. METHODS: A total of 117 mine drilling workers exposed to hand-transmitted vibration were selected as the exposure group, and 46 workers without hand-transmitted vibration exposure were selected as control group by judgment sampling method. The Occupational Epidemiology Questionnaire of Mine Drilling Workers was used to investigate their subjective symptoms. RESULTS: The prevalence of tinnitus, hearing loss, cough and sputum in the exposure group was higher than that in the control group(P<0.05). The occurrence rate of numbness, tingling, self-reported white fingers and cold hands in the exposure group was higher than that in the control group(P<0.05). The total rate of symptoms of hand in the exposure group was higher than that in the control group(38.5% vs 21.7%, P<0.05). The multivariate logistic regression analysis results indicated that hand-transmitted vibration exposure and service length were risk factors of abnormal hand symptoms(P<0.05). CONCLUSION: Occupational hand-transmitted vibration exposure can affect the hand subjective symptoms of mine drilling workers, and the length of service is a synergistic influencing factor.
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OBJECTIVE: To investigate the prevalence and risk factors of multi-site work-related musculoskeletal disorders(WMSDs) among workers in the industry of electronic equipment manufacturing. METHODS: A total of 815 workers in three factories of electronic equipment manufacturing in Guangdong Province were selected as study subjects by convenience sampling. The prevalence of multi-site WMSDs in the past year was investigated using Musculoskeletal Disorders Investigating Questionnaire and the influencing factors were analyzed. RESULTS: The total prevalence of WMSDs was 69.4%(566/815). The prevalence of multi-site WMSDs was 54.5%(444/815), and the prevalence of one-site WMSDs was 15.0%(122/815). Multiple logistic regression showed that female workers had higher prevalence of multi-site WMSDs than males [odds radio(OR) and 95% confidence interval(CI): 1.59(1.12-2.26), P<0.05]. The prevalence of multi-site WMSDs in left-handed workers was lower than that of right-handed workers [OR(95% CI): 0.42(0.19-0.91), P<0.05]. The longer service of current position and the more neck forward movement, the higher prevalence of multi-site WMSDs [OR(95% CI) were 1.33(1.09-1.63) and 1.62(1.23-2.15), P<0.01]. The workers who had long-time sitting at work, adopted uncomfortable working posture, could decide when to work on their own, kept head down for a long time, or often bending wrists up/down had higher prevalence of multi-site WMSDs [OR(95% CI) were 1.41(1.16-1.73), 1.82(1.40-2.38), 1.79(1.16-2.75), 1.92(1.38-2.69) and 1.60(1.14-2.24), respectively, P<0.01]. The workers who could take turns with colleagues to finish work or had enough rest time had lower prevalence of multi-site WMSDs [OR(95% CI): 0.57(0.41-0.78) and 0.67(0.48-0.92), P<0.05]. The workers who worked >10 h per day had lower prevalence of multi-site WMSDs than those who worked ≤8 h per day [OR(95% CI): 0.57(0.37-0.87), P<0.05]. CONCLUSION: Multi-site WMSDs were more common than one-site WMSDs among workers in the industry of electronic equipment manufacturing, and the prevalence of multi-site WMSDs was high. The risk factors include personal factors, work organization and adverse ergonomic factors.
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OBJECTIVE: To analyze the influence of noise measuring skills by continuous inter-laboratory comparison among occupational hygiene technical service organizations. METHODS: The results of 68, 55 and 50 occupational hygiene technical service organizations(reference organizations) participating in the inter-laboratory comparison of workplace noise measurement in 2014, 2017 and 2018 respectively were collected. The measurement operation and the calculation of equivalent sound level were evaluated according to the GBZ/T 189.8-2007 Measurement of Physical Agents in Workplace--Part 8: Noise.The measured results were analyzed by z score evaluation method. RESULTS: The results of noise measurement field operation of the reference organizations in the year 2014, 2017 and 2018 show that the accuracy rates of instrument setting was 89.7%, 98.2% and 100.0%, the accuracy rates of measuring position were 52.9%, 81.8% and 94.0%, the accuracy rates of sound level meter holding were 54.4%, 80.0% and 92.0%, the accuracy rates of microphone pointing were 98.5%, 98.2% and 94.0%, and the accuracy rates of noise type recognition were 83.8%, 92.7% and 84.0%, respectively. Among them, the accuracy of instrument setting, measurement position and sound level meter holding showed an increasing trend year by year(P<0.01). The pass rates of measurement results were 91.2%, 94.5% and 88.0% in 2014, 2017 and 2018 respectively. The pass rates of equivalent sound level calculation were 73.5%, 92.7% and 88.0%. The pass rates of comprehensive evaluation were 70.6%, 89.1% and 80.0% respectively. Among them, the pass rates of equivalent sound level calculation and comprehensive evaluation in 2017 were higher than that in 2014(P<0.017). There was no significant difference in the three-year comprehensive assessment total pass rate between private organizations and non-private organizations(84.0 % vs 75.5%, P>0.05). There was no significant difference in the total pass rate of three-year comprehensive evaluation between non-Pearl-River-Delta organizations and Pearl-River-Delta organizations(70.3% vs 81.6%, P>0.05). CONCLUSION: Continuous inter-laboratory comparison in occupational hygiene technical service organizations is beneficial to improve on-site noise measure capability.
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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 analyze the characteristics of noise hazard in a nuclear power station. METHODS: The workplaces and working posts which exposed to occupational noise from two 1 000 MW power units in one nuclear power station in Guangdong Province was selected as study subjects using the convenience sampling method. Occupational health survey, noise measurement in the workplace and personal noise dosage measurement were used to monitor noise exposure, and to analyze the characteristics of occupational noise in the nuclear power station. RESULTS: The noise sources of the nuclear power plant were mainly distributed in the nuclear island, conventional island, and peripheral workshops. A total of 237 points of noise intensity were measured in the workplace. The intensity of noise ranged from 66.0 to 99.6 dB(A). The noise intensity in 62.4%(148/237) of points was equal or greater than 80.0 dB(A) and 34.2%(81/237) equal or greater than 85.0 dB(A). The percentage of detection points with noise intensity was equal or greater than 85.0 dB(A) from low to high were nuclear island, conventional island, and peripheral workshops with 22.0%, 37.5% and 53.8% respectively(P<0.01). The personal noise intensity of three positions including inspectors of operation department, preparation and main engine positions of mechanical department exceeded the occupational exposure limit(OEL), and the percentage of positions whose noise intensity exceeded the OEL was 9.7%(3/31). CONCLUSION: High-intensity noise sources of the nuclear power plant are widely distributed in the workshop areas of nuclear island, conventional island, and peripheral workshops. The noise level of some positions exceeded the standards of noise intensity. The prevention and control measures of noise hazards in posts with excessive noise should be strengthened.
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OBJECTIVE: To analyze the effects of hand-transmitted vibration operation on nailfold capillaroscopy( NFC) in fine sanding workers. METHODS: A total of 57 fine sanding workers of one golf ball production enterprise in Guangdong Province were selected as vibration exposure group and 30 workers without exposure to hand-transmitted vibration as control group by a judgement sampling method. NFC examination was carried out in workers of these two groups. RESULTS: The capillary haemorrhage detection rates,percentage of abnormal capillary loops and total capillary width in the vibration exposure group were higher than that in the control group [43. 9% vs 13. 3%,( 56. 6 ± 20. 9) % vs( 41. 2 ± 14. 5) %,( 44. 7 ± 4. 9) vs( 42. 4 ± 4. 9) μm,P < 0. 05]. The capillary density,capillary length and branch diameter in the vibration exposure group were lower than that in the control group [( 7. 7 ± 1. 0) vs( 8. 8 ± 1. 0) per mm,( 185. 1 ± 33. 9) vs( 205. 6 ± 23. 2) μm,( 18. 3 ± 1. 9) vs( 19. 6 ± 2. 6) μm,P < 0. 05]. No significant difference was found in the diameter of apical part and branch of capillaries between the two groups( P > 0. 05). In the vibration exposure group,the percentage of abnormal capillary loops in the left hand was lower than that in the right hand [( 53. 1 ± 20. 6) % vs( 61. 5 ±24. 2) %,P < 0. 01],the capillary length in the left hand of vibration exposure group was longer than that in the right hand [( 187. 2 ± 33. 5) vs( 179. 4 ± 35. 4) μm,P < 0. 05]. No significant difference was found in the capillary density,total capillary width,apical part diameter,output branch diameter and input branch diameter between two hands in the vibration exposure group( P > 0. 05). CONCLUSION: The hand-transmitted vibration can lower the nailfold capillary density,shorten and widen capillary loops, increase percentage of abnormal capillary loops and induce capillary haemorrhage. NFC could be used to assist early detection of microvascular damage induced by hand-transmitted vibration.
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OBJECTIVE: To evaluate the exposure status of hand-transmitted vibration(HTV)in golf ball head grinding workers.METHODS: The golf ball head grinding positions in a sports equipment factory were selected as the research subjects by the judgement sampling method.The HTV exposure level of the workers in 66 grinding positions was measured,the key control points for HTV hazards were identified,and the damage of HTV was classified.RESULTS: The median(M)of 4 hours energy equivalent frequency-weighted acceleration to vibration[a_(hw(4))]of grinding positions in this sports equipment factory was 4.21 m/s~2,and the a_(hw(4)) over standard rate was 50.0%(33/66).The a_(hw(4)) of rough grinding positions was higher than that of fine grinding positions(M:5.50 v.s 3.94 m/s~2,P<0.05).In both rough grinding positions and fine grinding positions,the a_(hw(4)) of different ball head grinding types from high to low were hollow titanium alloy ball heads, hollow stainless steel ball heads,and solid stainless steel ball heads(rough grinding positions M:7.41 vs4.43 vs 3.11 m/s~2,P<0.01; fine grinding p ositions M:5.24 vs 4.21 vs 2.93 m/s~2,P<0.01).For the hollow titanium alloy ball head grinding positions,the a_(hw(4)) of rough grinding was higher than that of fine grinding(M:7.47 vs 5.24 m/s~2,P<0.01).Rough grinding positions,especially hollow stainless steel ball heads and hollow titanium alloy ball head grinding positions were key control points for HTV hazards.In the 66 grinding positions,the HTV hazards were classified as grade 0,Ⅰ,Ⅱ,and Ⅲ in the grinding positions accounted for 3.0%,47.0%,40.9%,and 9.1%,respectively,and those with grade Ⅱ and above were 50.0%(33/66). CONCLUSION: The exposure level of HTV in golf ball head grinding workers is high,with a trend of exceeding the standard.The golf ball head grinding workers have a high occupational health risk.
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OBJECTIVE: To analyze the characteristic change of fingertip vibrotactile perception threshold(VPT) at two different frequencies among mine drilling workers. METHODS: A total of 48 mine drilling workers exposed to hand-transmitted vibration for at least 1.0 year were selected from mines in Hubei Province as the vibration exposure group by using the random number table method, and workers without hand-transmitted vibration exposure were selected as the control group. An HVLab vibrotactile perception meter was used to measure the fingertip VPT at 31.5 and 125.0 Hz in workers of these two groups. RESULTS: None of the workers in these two groups showed any clinical symptoms associated with occupational hand-arm vibration diseases. At 31.5 and 125.0 Hz, the fingertip VPT in the vibration exposure group was higher than that in the control group(P<0.01), the fingertip VPT of the little fingers was higher than that of the index fingers(P<0.01). At 125.0 Hz, the fingertip VPT of the fingers in dominant hands was higher than that in non-dominant hands in workers of the vibration exposure group(P<0.01). CONCLUSION: The mine drilling workers with hand-transmitted vibration exposure had higher fingertip VPT. There were differences of VPT in fingers and dominant hands.