Factors associated with musculoskeletal pain in professional dancers, including lapse period of group practice due to the COVID-19 outbreak: repeated-measures analysis.

Background: This study investigated the prevalence and associated factors of musculoskeletal pain among professional dancers who experienced a lapse in group practice due to coronavirus disease 2019. Methods: General characteristics, practice time, region of musculoskeletal pain due to injury using the visual numeric scale (VNS), and causative motion were surveyed among professional dancers. Pain of VNS 0 to 3 was categorized as "no or minor," 4 to 6 was categorized as "moderate," and 7 to 10 was categorized as "severe." The causal motions of musculoskeletal pain were analyzed according to body region. Factors other than motion associated with pain were also analyzed. Results: In total, 368 participants were included. In the univariate analysis, age and practice time were positively associated with "moderate" pain. Practice time, dance experience, and postural accuracy were positively associated with "severe" pain, as was performing Korean traditional dance. In the multivariable analysis, practice time, group practice, and age were positively associated with pain of VNS 4 to 10, and practice time, group practice, and Korean traditional dance were positively associated with pain of VNS 7 to 10. Conclusion: Among the factors related to dancer training, practice time, group practice, and dance type affect the occurrence of pain.

The association of job training duration and risk of depression among wage workers: an analysis of the mediating factors.

Background: Research on job training and job satisfaction has been conducted from various perspectives. Job training is thought to be associated with job satisfaction, which is known as an important factor for depression among workers. We hypothesized that job training duration could influence depression through potential mediators (job satisfaction, motivation to work, and work engagement). Methods: This study encompassed participants from the sixth Korean Working Conditions Survey (KWCS), conducted between 2020 and 2021. To show the relationships between demographic or occupational characteristics and risk of depression, a χ2 test was conducted. The association between job training duration, potential mediators, and risk of depression was analyzed by constructing multiple logistic regression models. The mediating effects of potential mediators on job training duration and risk of depression was evaluated with flexible mediation analysis with weighting-based methods. Results: The final study population consisted of 25,294 participants. Longer job training duration significantly decreased risk of depression after adjusting for confounders. In the group that received the longest job training duration (≥ 10 days), compared with the group without job training, the odds ratio (OR) for high risk of depression was 0.46 (95% confidence interval [CI], 0.39-0.54). Each three potential mediators showed statistically significant indirect effects and direct effect. Although indirect effects were not strong compared to direct effect, motivation to work had the strongest mediating effect in this study, with an OR of 0.94 (95% CI, 0.92-0.95). Conclusions: Job training duration was found to have a statistically significant negative association on the risk of depression, and three mediators partially mediating this effect. Although the mechanism was unknown, our findings suggest that job training has a positive influence on workers' mental health. Furthermore, by suggesting the possibility of other pathways existing between job training and depression, we provide directions for future research.

Increase of blood mercury level with shark meat consumption: A repeated-measures study before and after Chuseok, Korean holiday.

Sharks are known to contain high levels of mercury in their meat. However, few studies have directly assessed the changes in mercury concentration in the human body according to shark meat intake. One hundred and ninety-seven participants that traditionally consume shark meat during the Chuseok holiday were recruited from two areas of Gyeongsangbuk-do, South Korea to examine their blood mercury level before and after the holiday season. Blood mercury levels were measured before and after the holiday season. Characteristics such as the consumption of shark meat, intake amount, and the effect on mercury concentration were assessed during the survey. Univariable and multivariable analysis (Linear Mixed Model) were done for assessing the association between shark meat consumption of holiday season and blood mercury level. Among the total participants, 83 consumed shark meat during holiday. In the univariable analysis, a significant increase in blood mercury levels before and after Chuseok was observed only for the group that consumed shark meat during holiday. The multivariable analysis (adjusted for identified confounders that affect both exposure and outcome considering repeated measurements) showed that consuming shark meat was significantly associated with increased blood mercury levels by 3.56 µg/L (95% confidence interval [CI], 2.64-4.67 µg/L). In the model considering the amount consumed as two group, the level of increase was 2.61 µg/L (95% CI, 1.63-3.58 µg/L) for those consuming <100 g, and 6.20 µg/L (95% CI, 4.77-7.62 µg/L) for those consuming ≥100 g compared to group without consuming shark meat. Considering amount consumed as continuous value, 0.02 µg/L (95% CI, 0.01-0.02 µg/L) of blood mercury increase was significantly associated with consuming 1 g. Consumption of shark meat significantly elevated blood mercury levels, exceeding commonly suggested reference concentrations in less than 2 weeks. These findings suggest the need for public health warnings and regulations regarding shark meat consumption.

Association of heavy metal complex exposure and neurobehavioral function of children.

Background: Exposure to heavy metals is a public health concern worldwide. Previous studies on the association between heavy metal exposure and neurobehavioral functions in children have focused on single exposures and clinical manifestations. However, the present study evaluated the effects of heavy metal complex exposure on subclinical neurobehavioral function using a Korean Computerized Neurobehavior Test (KCNT). Methods: Urinary mercury, lead, cadmium analyses as well as symbol digit substitution (SDS) and choice reaction time (CRT) tests of the KCNT were conducted in children aged between 10 and 12 years. Reaction time and urinary heavy metal levels were analyzed using partial correlation, linear regression, Bayesian kernel machine regression (BKMR), the weighted quantile sum (WQS) regression and quantile G-computation analysis. Results: Participants of 203 SDS tests and 198 CRT tests were analyzed, excluding poor cooperation and inappropriate urine sample. Partial correlation analysis revealed no association between neurobehavioral function and exposure to individual heavy metals. The result of multiple linear regression shows significant positive association between urinary lead, mercury, and CRT. BMKR, WQS regression and quantile G-computation analysis showed a statistically significant positive association between complex urinary heavy metal concentrations, especially lead and mercury, and reaction time. Conclusions: Assuming complex exposures, urinary heavy metal concentrations showed a statistically significant positive association with CRT. These results suggest that heavy metal complex exposure during childhood should be evaluated and managed strictly.

The Impact of Aircraft Noise on the Cognitive Function of Elementary School Students in Korea.

Background: This study evaluated the effects of chronic exposure to aircraft noise on the cognitive functions of Korean elementary school students attending an elementary school around a military airfield and clarified the relationship between noise exposure and cognitive functions. Methods: Five schools with average weight equivalent continuous perceived noise levels (WECPNL) of ≥75 dB were selected from four regions in Korea. Each of these schools was matched with a non-exposed school. The Korean Intelligence Test Primary (KIT-P) was used to measure the scores of four subcategories and the intelligence quotient (IQ). The noise exposure groups were divided into high-exposure (WECPNL ≥ 80 dB) and medium-exposure (75 ≤ WECPNL < 80) groups. The period of exposure during the school year was collected. A linear mixed model, with matched pairs of schools, was used for statistical analysis. Results: In the multivariable linear mixed model adjusted by possible confounders, the reasoning score was significantly lower in the high-exposure group of students than in the no-exposure group. Other scores and IQ were lower in the noise exposure groups, although these were not statistically significant. The duration of exposure did not show a significant relationship with cognitive functions. Conclusion: Chronic exposure to noise from military airfields may influence the cognitive functions, thereby reducing the learning performance of Korean children.

Risk assessment of heavy metals in tuna from Japanese restaurants in the Republic of Korea.

Background: Studies on the risk of mercury (Hg) in Korean fishery products focus primarily on total Hg levels as opposed to methylmercury (MeHg) levels. None of the few studies on MeHg in tuna investigated tuna from Japanese restaurants. Few have evaluated lead (Pb), cadmium (Cd) and arsenic (As) in tuna. Thus, this study aimed to conduct a risk assessment by evaluating heavy metal concentrations in tuna from Japanese restaurants. Methods: Thirty-one tuna samples were collected from Japanese restaurants in the Republic of Korea. They were classified according to region and species. The concentration of heavy metals in the samples was analyzed using the Ministry of Food and Drug Safety Food Code method. The rate of exceedance of maximum residue levels (MRLs) and the risk compared to the provisional tolerable weekly intake (PTWI) set by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (%PTWI) were evaluated for risk assessment. Results: The mean of MeHg, Pb, Cd and As concentrations were 0.56 ± 1.47 mg/kg, 33.95 ± 3.74 µg/kg, 14.25 ± 2.19 µg/kg and 1.46 ± 1.89 mg/kg, respectively. No sample exceeded the MRLs of Pb and Cd, but 9.7% of the samples exceeded the MRL of MeHg. The %PTWIs of MeHg, Pb, Cd and As were 4.2037, 0.0162, 0.0244 and 1.1627, respectively. The %PTWI of MeHg by age group and sex was highest among men aged 19-29 years (10.6494), followed by men aged 30-49 years (7.2458) and women aged 19-29 years (4.8307). Conclusions: We found that 3 out of 31 samples exceeded the MRL of MeHg. The %PTWI of MeHg showed significant differences based on age and sex, and the value was likely to exceed a safe level depending on individuals' eating behaviors. Therefore, improved risk management for MeHg is required.

An outbreak of neurologic symptoms among patients exposed to an unknown stench in a high school near an industrial complex: an epidemiological investigation.

OBJECTIVES: Seven students at a high school in Korea visited the emergency room with non-specific neurological symptoms after a stench was noticed during a school entrance ceremony. In relation to this incident, 105 patients visited medical institutions over 5 days. A team of environmental and epidemiological experts was assembled to investigate the incident. METHODS: Our team of experts participated in the investigation 1 month post-incident. Previously, only air samples had been analyzed. We received results of air samples analyzed by other investigators, medical records of some students, and data from police interviews of patients. Additional investigation and interviews were conducted, and the events were reconstructed in spatial and temporal order. RESULTS: A cluster of patients was observed on the south side and parts of the north side of the upper floor. A stench like that reported during the incident had been noticed for about 2 years near the school. Students consistently described a similar stench occurring frequently in the vicinity of the school. According to student statements, the odor mainly resembled something burning. The carboxyhemoglobin levels of some students were observed to be >1.5%. CONCLUSIONS: In the investigation, 2 suspected sources were identified: a science room storing chemicals downstairs from the auditorium and various industrial facilities near the school. Combining the scattered evidence, we considered a toxic puff of gas, perhaps from brief incineration or leakage in a specific area, to be the likely cause of the incident. We describe our approach and the limitations encountered during the investigation.

Systematic review and meta-analysis of cancer risks in relation to environmental waste incinerator emissions: a meta-analysis of case-control and cohort studies.

OBJECTIVES: Various toxic substances can be generated from incinerators, exposing nearby residents, and epidemiological studies have shown wide variations in risk estimates for cancer risk in populations living close to incinerators. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a literature search and systematic review were conducted to identify studies conducted on general populations exposed to environmental incinerator emissions and cancer outcomes. Meta-analysis was performed according to the cancer types for which 2 or more studies were reported. Subgroup analysis was done for sex, the exposure estimation method, the study period, and the type of outcome. RESULTS: Eleven studies were found for the qualitative review and meta-analysis. Seven studies had a case-control design, and 4 had a cohort design. The pooled effect size was not significant for breast, colorectal, liver, lung, lymphohematopoietic, stomach, bladder, central nervous system, and laryngeal cancers, non-Hodgkin lymphoma, sarcoma, leukemia, and all cancers. In the subgroup analysis, the pooled effect size of laryngeal cancer in females was 1.82 (95% confidence interval, 1.10 to 3.01), although only 2 studies were identified. CONCLUSIONS: The meta-analysis did not provide evidence of an increased risk for any cancer among populations living near waste incinerators, except for laryngeal cancer in females. However, since relatively few studies were reviewed and some cancer types showed significant increases in individual studies, this evidence needs to be updated regularly.

Association between exposure to particulate matter and school absences in Korean asthmatic adolescents.

Background: Because particulate matter (PM) and asthma are closely related, the prevalence of school absence among adolescents with asthma can be affected by the concentration of PM. We aimed to investigate the relationship between school absences due to asthma and the total number of days that the PM concentration exceeded the standard. Methods: We used the data from the 16th Korea Youth Risk Behavior Survey and the PM levels of 17 metropolitan cities and provinces gathered from the AirKorea. Information on the characteristics of asthmatic adolescents and the prevalence of school absence was obtained using a questionnaire, while the PM levels based on the total number of days with poor and very poor PM grades were collected from the AirKorea website. Both χ2 test and logistic regression analysis were performed using the weights presented in the original dataset. Results: In the case of particulate matter of 10 microns in diameter or smaller (PM10), the odds ratio (OR) after adjusting for confounders (sex, school year, body mass index, smoking history, diagnosis of allergic rhinitis, diagnosis of atopic dermatitis and city size) was 1.07 (95% confidence interval [CI]: 1.01-1.13) for absents due to asthma when the total days of poor and very poor grades of PM10 (81 µg/m3 or higher) increased by 1 day. In the analysis of particulate matter of 2.5 microns in diameter or smaller (PM2.5), the OR after adjusting for confounders was 1.01 (95% CI: 1.00-1.03) for absents due to asthma when the total number of days with poor and very poor PM2.5 grades (36 µg/m3 or higher) increased by 1 day. Conclusions: A significant association was observed between the total number of days of poor and very poor PM10 and PM2.5 grades and school absence due to asthma; PM can cause asthma exacerbation and affect the academic life.

Influence of temperature and precipitation on the incidence of hepatitis A in Seoul, Republic of Korea: a time series analysis using distributed lag linear and non-linear model.

This study aimed to analyze the association between temperature and precipitation and the incidence of hepatitis A in Seoul, Korea, as meteorological factors may have different effects on specific diseases depending on the lifestyle in each region. Weekly cases of hepatitis A, weekly mean daily precipitation, and temperature data from 2016 to 2020 were analyzed. Quasi-Poisson-generalized linear models with time variable adjusted by spline function were used considering 0-6-week lags. The association of each variable and hepatitis A incidence was assessed by the single lag and the constrained distributed lag model. Multivariable distributed lag linear and non-linear models were used to develop models with significant independent variables. Weekly mean of daily mean temperature (Tmean) and maximum temperature (Tmax) were negatively associated with hepatitis A in the 6-week lag. Precipitation was negatively associated with hepatitis A in the 5- and 6-week lags. The multivariable model showed the negative association of Tmax, precipitation and hepatitis A in the 5- and 6-week lags. In the non-linear models, the incidence rate ratio (IRR) was the highest at a Tmax of 11 °C and decreased thereafter. IRR was the highest at 12 mm of precipitation and showed decrease pattern to 25 mm and then gradually increased in the 5- and 6-week lags. Identifying the impact of climate factors on hepatitis A incidence would help in the development of strategies to prevent diseases and indirectly estimate the impact of climate change on hepatitis A epidemiology.

Preventive Measures Against COVID-19 in Small- and Mid-sized Enterprises from an Early Stage of the Epidemic in Daegu and Gyeongsangbuk-do.

Background: In the early stage of the coronavirus disease 2019 (COVID-19) epidemic, small- and mid-sized enterprises (SMEs) may be an important transmission consideration. The study aimed to identify the pattern of COVID-19 prevention measures during the outbreaks in Daegu and Gyeongsangbuk-do at the early stage of COVID-19. Moreover, we investigated whether SME size and past experiences affected the preventive measures implemented in the region. Methods: A survey detailing the general characteristics and implementation of 12 preventive activities was conducted in 122 SMEs in Daegu and Gyeongsangbuk-do. The survey was analyzed by size and operation period. Results: The study subjects consisted of 53 (43.4%) workplaces with 1-5 employees, 50 (40.9%) workplaces with 6-30 employees, and 19 (15.6%) workplaces with 31-49 employees. The lowest three items among those surveyed were 'symptomatic workers to stay home for 3-4 days' (17.2%), 'work remotely' (18.9%), and 'video meetings' (20.5%). There were significant differences in the rate of several preventive measures implemented. The larger sized SMEs, the higher the number of implementations (p < 0.01). The operation period had no significant relationship with the implementation of preventive measures. The same pattern was observed in multiple generalized linear regression with covariate adjustment. Conclusion: Preventive measures among SMEs with fewer than 50 employees were identified. Even within SMEs, a gap in preventive measures according to size was confirmed. To prevent the spread of infection and protect workers' right to health, different support for different sized SMEs is necessary.

Carbon Monoxide Poisoning and Developing Ischemic Heart Disease: A Nationwide Population-Based Nested Case-Control Study.

Although there are several case reports showing that carbon monoxide (CO) poisoning causes ischemic heart disease (IHD), no large-scale epidemiological studies have shown a significant association between the two. To investigate the association between CO poisoning and IHD, a nested case-control study of 28,113 patients who experienced CO poisoning and 28,113 controls matched by sex and age was performed using the nationwide health database of South Korea. Based on a conditional logistic regression, there was a significantly higher risk of IHD among the CO poisoning group than among the control group (adjusted hazard ratio [HR], 2.16; 95% confidence interval [CI], 1.87-2.49). The risk of IHD after CO poisoning was higher among the younger age group under 40 years (adjusted HR, 4.85; 95% CI, 3.20-7.35), and it was much greater among those with comorbidities (adjusted HR, 10.69; 95% CI, 2.41-47.51). The risk of IHD was the highest within the first two years after CO poisoning (adjusted HR, 11.12; 95% CI, 4.54-27.22). Even if more than six years had passed, the risk was still significantly higher than among the control group (adjusted HR, 1.55; 95% CI, 1.27-1.89). The analyses imply that CO poisoning is associated with an increased risk of IHD.

Exposure to diesel engine exhausts and increase of urinary 8-hydroxy-2'-deoxyguanosine among Male tank maintenance workers in the Republic of Korea Army.

This study was conducted to evaluate the exposure of diesel engine exhaust (DEE) and oxidative stress among tank maintenance workers in the Republic of Korea Army. Airborne concentrations of elemental carbon (EC), polycyclic aromatic hydrocarbons (PAHs), and metals were measured at two units. Urine analysis for 1-hydroxypyrene and 8-hydroxy-2'-deoxyguanosine (8-OHdG) was performed for tank maintenance workers from one unit (n=17). To compare the level of 8-OHdG, the analysis was performed in 17 unexposed controls. The airborne EC concentration was 8.6-24.3 µg/m3 in indoor unit. EC was not detected in the outdoor unit. As for the PAHs, trace -0.0004 mg/m3 of naphthalene was detected. ITWA for 26 metals was calculated to be 0.009-0.027. The geometric mean urinary 1-hydroxypyrene was 0.08 µg/g creatinine. The geometric mean of 8-OHdG was 1.04 µg/g for the maintenance workers, while 0.45 µg/g for controls. The level of urinary 8-OHdG was significantly higher among maintenance workers in multivariate analysis. In conclusion, tank maintenance workers are exposed to various by-products from diesel engine combustion during work, and their level of oxidative stress marker was increased. Countermeasures for reducing hazardous substances in the military workplace are necessary.

Adverse Effects on Work and Daily Life Interference among Healthcare Workers after the First and Second ChAdOx1 and BNT162b2 COVID-19 Vaccine Doses.

In this study, we assessed the adverse effects and the work and daily life interference associated with each dose of the ChAdOx1 and BNT162b2 COVID-19 vaccines. Questionnaires were distributed to workers after they received both doses; only those who worked the day after receiving the vaccine were included in the analysis. Overall, 368 ChAdOx1-vaccinated and 27 BNT162b2-vaccinated participants were included. Among the ChAdOx1-vaccinated participants, the incidence of adverse effects was significantly lower after the second dose than after the first dose. Among the BNT162b2-vaccinated participants, however, no differences in adverse effects or work and daily life interference were found between the doses. After the first and second dose, the numeric scale score (0-10) for interference with work was 3.9 ± 2.9 and 1.6 ± 1.9 for the ChAdOx1 and 3.2 ± 2.5 and 3.6 ± 3.0 for the BNT162b2 vaccine, respectively. A similar trend was observed for interference with daily life. Factors associated with work and daily life interference in the multivariate model were age, vaccine dose (first or second), and the interaction term of vaccine type and dose. These results could be used to inform the general population of the adverse effects associated with these vaccinations.

Association between physical hazardous agent exposure and mental health in the Korean working population: the 5th Korean Working Conditions Survey.

BACKGROUND: Mental health problems are emerging issues in occupational safety and health, whereas the findings on the relationship between physical hazards and mental health are not consistent. The aim of our study was to investigate the association between physical hazard exposure and mental health outcomes including depression and anxiety. METHODS: We included 48,476 participants from the fifth Korean Working Conditions Survey (KWCS) in this study. The χ2 test and logistic regression analyses were conducted to assess the association between physical hazard exposures and mental health. All statistical analyses were performed sex-specifically. RESULTS: In logistic regression analysis, the odds ratios (ORs) of depression were significantly increased in male workers who were exposed to vibration (severe OR: 1.54, 95% confidence interval [CI]: 1.21-1.95) and noise (severe OR: 1.93, 95% CI: 1.49-2.48) whereas the ORs of depression were not significant in female workers from vibration (severe OR: 0.86, 95% CI: 0.50-1.38) or noise exposure (severe OR: 1.39, 95% CI: 0.84-2.17). The ORs of anxiety were significantly increased in male workers with vibration (severe OR: 1.76, 95% CI: 1.43-2.15) and noise exposure (severe OR: 2.12, 95% CI: 1.69-2.63) whereas the OR between vibration and anxiety (severe OR: 1.45, 95% CI: 0.91-2.21) was not significant in female workers. High or low temperature exposure had significant associations with depression and anxiety in both male and female subjects. CONCLUSIONS: Results of our study suggest that physical hazard exposures may be associated with increased risk of mental health problems including depression and anxiety. These associations are more prominent in male workers in comparison with female workers.

A Study on Concentration, Identification, and Reduction of Airborne Microorganisms in the Military Working Dog Clinic.

BACKGROUND: The study was planned to show the status of indoor microorganisms and the status of the reduction device in the military dog clinic. METHODS: Airborne microbes were analyzed according to the number of daily patient canines. For identification of bacteria, sampled bacteria was identified using VITEK®2 and molecular method. The status of indoor microorganisms according to the operation of the ventilation system was analyzed. RESULTS: Airborne bacteria and fungi concentrations were 1000.6 ± 800.7 CFU/m3 and 324.7 ± 245.8 CFU/m3. In the analysis using automated identification system, based on fluorescence biochemical test, VITEK®2, mainly human pathogenic bacteria were identified. The three most frequently isolated genera were Kocuria (26.6%), Staphylococcus (24.48%), and Granulicatella (12.7%). The results analyzed by molecular method were detected in the order of Kocuria (22.6%), followed by Macrococcus (18.1%), Glutamicibacter (11.1%), and so on. When the ventilation system was operated appropriately, the airborne bacteria and fungi level were significantly decreased. CONCLUSION: Airborne bacteria in the clinic tend to increase with the number of canines. Human pathogenic bacteria were mainly detected in VITEK®2, and relatively various bacteria were detected in molecular analysis. A decrease in the level of bacteria and fungi was observed with proper operation of the ventilation system.

Pneumoconiosis in a polytetrafluoroethylene (PTFE) spray worker: a case report with an occupational hygiene study.

BACKGROUND: Using analysis of air samples from the workplace, we report on one case of pneumoconiosis in an individual who has been working in a polytetrafluoroethylene (PTFE) spraying process for 28 years. CASE PRESENTATION: The patient was diagnosed with granulomatous lung disease caused by PTFE using computed tomography (CT), lung biopsy and electron microscopy. To assess the qualitative and quantitative exposure to PTFE in workplace, Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX) and thermogravimetric analysis (TGA) were performed on air samples from the workplace. The presence of PTFE particles was confirmed, and the airborne concentration of PTFE was estimated to be 0.75 mg/m3. CONCLUSIONS: This case demonstrates that long-term exposure to PTFE spraying can cause granulomatous lung lesions such as pneumoconiosis; such lesions appear to be caused not by the degradation products of PTFE from high temperatures but by spraying the particles of PTFE. Along with air-sampling analysis, we suggest monitoring the concentration of airborne PTFE particles related to chronic lung disease.

The Association of Workplace Psychosocial Factors and Musculoskeletal Pain Among Korean Emotional Laborers.

BACKGROUND: Many studies have reported negative psychological or physical effects of emotional labor. Relationship between work-related musculoskeletal disorder and psychosocial factors has been reported. To manage organizational and psychosocial factors of musculoskeletal disorder with work place intervention among emotional laborers, the factors contributing to musculoskeletal pain must be identified and clarified. METHODS: Data from the fourth Korean Working Conditions Survey was analyzed. Based on the questionnaire, we selected emotional laborers and included 3,979 participants, excluding participants whose variables were of interest to the researcher. Weight variable was applied. The association with musculoskeletal pain and psychosocial factors, such as workload, monotonous work, job control, social support, and job satisfaction, was investigated. RESULTS: Univariate analysis demonstrated that there was a statistically significant relationship between social support, job satisfaction, and musculoskeletal pain. In multivariate analysis, job satisfaction showed a strong correlation with musculoskeletal pain at all sites. Social support was significantly associated with backache. Monotonous work seemed to reduce the pain in the neck and/or upper limbs. Job control and work intensity were not significantly associated with musculoskeletal pain. CONCLUSION: In this study, job satisfaction was significantly associated with musculoskeletal pain, and social support among the social psychological stressors could reduce musculoskeletal pain. However, unlike previously known, the presence of monotonous work resulted in reduced musculoskeletal pain. The results of this study will help to establish the direction of improvement of atmosphere in the workplace to prevent the musculoskeletal pain of emotional laborers.

Cadmium Exposure Is Associated with Monocyte Count and Monocyte to HDL Ratio, a Marker of Inflammation and Future Cardiovascular Disease in the Male Population.

Cadmium is a heavy metal that humans can be exposed to the in environment and occupation, and its relationship with cardiovascular diseases has been reported. in various reports. Epidemiological studies have also been associated with various inflammatory markers of cardiovascular diseases. In this study, we examined the relationship between monocyte count and monocyte to high density lipoprotein (HDL) ratio (MHR) and blood cadmium, which are one of the inflammatory markers of cardiovascular diseases. Data from a total of 733 male fire officers who received a health checkup at a hospital for one year in 2016 were analyzed. Populations were classified into 4 groups according to the quartile of blood cadmium and general characteristics were described. The relationship between monocyte count, MHR and cadmium in blood was statistically analyzed by linear regression analysis. In the univariate analysis and multivariate analysis, monocyte count was significantly higher in the second, third and fourth quartile groups than in the first quartile of cadmium, and the linear trend was significant. In univariate and multivariate analysis, MHR was significantly higher in the third and fourth quartile groups than in the first quartile group, and the linear trend was also significant. This study showed the significant relationship between blood cadmium and monocyte count and MHR among male fire officers. This was also statistically significant in the model adjusted for possible confounders and other cardiovascular risk factors and showed a linear trend.

Association of arsenobetaine with beta-cell function assessed by homeostasis model assessment (HOMA) in nondiabetic Koreans: data from the fourth Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2009.

BACKGROUND: Arsenic is known as an endocrine disruptor that people are exposed to through various sources such as drinking water and indigestion of marine products. Although some epidemiological and animal studies have reported a correlation between arsenic exposure and diabetes development, there are limited studies regarding the toxic effects of organic arsenic including arsenobetaine on the human body. Here, we analyzed the association between urine arsenobetaine and the homeostasis model assessment of ß-cell function (HOMA-ß), which is an index for predicting diabetes development and reflecting the function of pancreatic ß-cells. METHODS: In the fourth Korea National Health and Nutrition Examination Survey (KNHANES), health and nutrition surveys and screening tests were performed. Of the total survey population, people with confirmed values for urine total arsenic and arsenobetaine were included, and known diabetic patients were excluded. A total 369 participants were finally included in the study. We collected surveys on health, height, body weight, body mass index, blood mercury level, fasting glucose level, and serum insulin level and calculated HOMA index. Owing to sexual discrepancy, we performed sexually stratified analysis. RESULTS: Urine total arsenic and total arsenic minus arsenobetaine was not associated with HOMA-IR and HOMA-ß in univariate analysis or in sexually stratified analysis. However, urine arsenobetaine showed a statistically significant relationship with HOMA-ß in univariate analysis, and only male participants showed a significant correlation in sexually stratified analysis. In the analysis adjusted for age, BMI, smoking, alcohol drinking, physical activity and blood mercury, the HOMA-ß value in the group below the 25th percentile of arsenobetaine was significantly higher than the group between 50 and 75th percentile, while no difference was shown for HOMA-IR. In sexually stratified analysis, The value of HOMA-ß was significantly higher in male participants with below the 25th percentile urine arsenobetaine than the group between 25 and 50th and between 50 and 75th, while no difference was shown for HOMA-IR. However, female participants did not demonstrate a relationship between HOMA-IR, HOMA-ß and urine arsenobetaine. CONCLUSION: This study revealed the association between urine arsenobetaine and pancreatic ß-cell function assessed by HOMA-ß in the normal population (without diabetes), especially in males, despite adjusting for factors affecting pancreatic ß-cell function and diabetes.