The Association Between Blood Lead Levels and Coronary Artery Calcium Score Determined by Using Coronary Computed Tomography Angiography

Background@#Lead exposure is a known risk factor for cardiovascular disease (CVD), and coronary artery calcification (CAC) is a biomarker for diagnosing atherosclerotic CVD. This study investigated the association between blood lead level (BLL) and CAC using coronary computed tomography (CT) angiography. @*Methods@#This study enrolled 2,189 participants from the general population with no history or symptoms of CVD. All participants underwent coronary CT angiography, health examination, and BLL testing. The association between coronary artery calcium score (CACS) and BLL was analyzed. @*Results@#The arithmetic mean of BLL was 2.71 ± 1.26 μg/dL, and the geometric mean was 2.42 (1.64) μg/dL, ranging from 0.12 to 10.14 μg/dL. There was a statistically significant positive correlation between CACS and BLL (r = 0.073, P 0, < 10), 2.81 ± 1.25 μg/dL; mild grade (≥ 10, < 100), 2.74 ± 1.29 μg/dL; moderate grade (≥ 100, < 400), 2.88 ± 1.38 μg/dL; severe grade (≥ 400): 3.22 ± 1.68 μg/dL. The odds ratio for severe CAC was 1.242 in association with an 1 μg/dL increase in BLL (P = 0.042). @*Conclusion@#Using coronary CT angiography, we determined a positive correlation between BLL and CAC among participants without CVD from the general population. To reduce the burden of CVD, efforts and policies should be geared toward minimizing environmental lead exposure.

Changes in the Health Indicators of Hospital Medical Residents During the Four-Year Training Period in Korea

Background@#In South Korea, the legal maximum working hours per week for medical residents is 88 hours, which are longer than those for other occupations, and the intensity of the workload is also remarkably high. Long working hours and job-related stress can worsen the health status of residents. This study aimed to analyze the four-year annual health checkup (AHC) data of residents to identify changes in their health indicators. @*Methods@#This study included 457 male residents who received 4 years of training at a university hospital. They underwent an AHC every year during the training period. Changes in health indicators and related factors over the 4 years were investigated. @*Results@#Body mass indices (BMI), blood pressures (BPs), liver function test (LFT) results, and total cholesterol (TC) levels were significantly worsened during the training period.The increases were the highest in the early training years, between the 2 nd and 1 st AHC.The working hours of the fourth-year residents were the shortest and showed low smoking and drinking rates and high regular exercise rates. On comparing by department, surgical residents showed the highest increases in BMI, diastolic BP, and fasting blood glucose (FBG), LFT enzyme, and TC levels during the training period, compared to residents from the medical and clinical support departments. Residents who were working ≥ 80 hours showed significantly higher FBG and LFT enzyme levels than those working < 80 hours. @*Conclusion@#This study is meaningful as it is the first study in Korea to investigate the changes in the health of residents through objective health indicators. The possibility of the 4-year training period adversely affecting the health of residents was confirmed. Health indicators were significantly worsened, especially in the early training period, in surgical residents, and in residents who worked for long hours. Efforts are needed to restrict long working hours and distribute workload during the 4-year training period.

Twenty-year incidence trend of hematologic malignancies in the Republic of Korea: 1999‒2018

Background@#In this study, we presented the national cancer statistics on the incidence of hematologic malignancies in the Republic of Korea (ROK) over a period of 20 years, from 1999 to 2018. @*Methods@#We obtained data on the incidence of hematologic malignancies using the Korean Statistical Information Service (KOSIS). For each hematologic malignancy, the number of cases, crude incidence rate, and age-standardized incidence rate were calculated, and the statistical trends were confirmed by Poisson regression and Joinpoint regression analysis. @*Results@#All the investigated hematologic malignancies showed a statistically significant increase in incidence over 20 years. The 20-year trend of the age-standardized incidence rate was as follows: non-Hodgkin lymphoma [average annual percent change (AAPC)=2.26%, P-trend ＜0.05], leukemia (AAPC=0.94%, P-trend ＜0.05), myeloid leukemia (AAPC=1.44%, P-trend ＜0.05), multiple myeloma (AAPC=3.05%, P-trend ＜0.05), myeloproliferative disorders (AAPC=9.87%, P-trend ＜0.05), myelodysplastic syndrome (AAPC=7.59%, P-trend ＜0.05), malignant immunoproliferative diseases (AAPC=11.82%, P-trend ＜0.05), lymphoid leukemia (AAPC=2.21%, P-trend ＜0.05), and Hodgkin lymphoma (AAPC=4.04%, P ＜0.05). @*Conclusion@#It was confirmed that the incidence of hematologic malignancies has increased significantly in the ROK over the past 20 years. This study can be used as foundational data source for future studies. In addition, it can aid in the necessary actions of predicting future incidences and establishing future healthcare policies.

Night Work and Its Health Effects: Focusing on the Relevant Laws and Regulations of the Republic of Korea

The modern world is a 24-hour society. Night work exists for the public’s convenience and interest, owing to the unstoppable nature of industries and the benefits it has for companies. Approximately 10.2–14.5% of workers in the Republic of Korea and approximately 20% of workers worldwide work at night. These workers are at an increased risk of various health problems, including sleep disorders, cerebrovascular disease, digestive system disease, metabolic syndrome, fatigue, risk of accidents, cancer, irregular menstrual cycles, depression, and mental illness. In this study, we reviewed the Korean government’s legal system and guidelines to protect night workers’ health. These systems include restrictions on working hours, allowances for night work, special health checkups, compensation for night work-related diseases, and active health promotion measures. Humans cannot adapt to night work completely, and social consensus and efforts are needed to reduce the burden on night workers. Current laws and regulations should be improved for night workers.

Night Work and Its Health Effects: Focusing on the Relevant Laws and Regulations of the Republic of Korea

The modern world is a 24-hour society. Night work exists for the public’s convenience and interest, owing to the unstoppable nature of industries and the benefits it has for companies. Approximately 10.2–14.5% of workers in the Republic of Korea and approximately 20% of workers worldwide work at night. These workers are at an increased risk of various health problems, including sleep disorders, cerebrovascular disease, digestive system disease, metabolic syndrome, fatigue, risk of accidents, cancer, irregular menstrual cycles, depression, and mental illness. In this study, we reviewed the Korean government’s legal system and guidelines to protect night workers’ health. These systems include restrictions on working hours, allowances for night work, special health checkups, compensation for night work-related diseases, and active health promotion measures. Humans cannot adapt to night work completely, and social consensus and efforts are needed to reduce the burden on night workers. Current laws and regulations should be improved for night workers.

The association between serum dehydroepiandrosterone sulfate (DHEAS) levels and job-related stress among female nurses

BACKGROUND: Dehydroepiandrosterone sulfate (DHEAS) is an endogenous steroid hormone produced by the adrenal gland. DHEAS has been suggested to play a protective role against psychosocial stress. The aim of this study was to investigate the association between job-related stress and blood concentrations of DHEAS according to occupational stress factors among female nurses. METHODS: A cross-sectional study was conducted among 118 premenopausal nurses from 4 departments (operating room, emergency room [ER], intensive care unit, and ward) of a university hospital. Participants were all rotating night shift workers who have worked for over a year and mean age of 33.5 ± 4.8 years. Data from structured questionnaires including the Korean Occupational Stress Score, Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), and Pittsburgh Sleep Quality Index (PSQI) were used. RESULTS: In the high job-related stressor group, scores of BDI, BAI, and PSQI were significantly higher than low-stressor group. ER nurses had relatively more work-burden related stressors, but they had significantly lower levels of anxiety and depression than other groups. And, ER nurses showed higher levels of DHEAS than the other department nurses. The differences were significant (p = 0.003). Additionally, there was a statistically significant difference even after adjusting for factors that could affect level of DHEAS, such as age, body mass index, drinking, and physical activity (p = 0.039). CONCLUSIONS: This result suggests the possibility that DHEAS may play a role as a marker of proper stress management. The capacity to secrete DHEAS is not simply due to workload or job stressor but could be determined depending on how individuals and groups deal with and resolve stress. Proper resolution of stress may affect positive hormone secretion.

Night shiftwork and prostate-specific antigen level in a tire manufacturing factory

BACKGROUND: Recent studies suggest that night shiftwork may increase the risk of prostate cancer and elevated serum prostate-specific antigen (PSA) level. The purpose of this study was to verify whether rotating night shiftwork affects serum PSA level. METHODS: This study included 3,195 male production workers who work in a large tire manufacturing factory. Serum PSA levels were measured and the data on related factors were obtained. RESULTS: The mean serum PSA level was 0.98 ± 0.79 ng/mL. PSA levels were significantly lower in the younger age group, the obese group, and regular exercise group. PSA levels were lower in night shift workers (n = 2,832) compared to day workers (n = 363), but the difference was not statistically significant. CONCLUSIONS: Unlike previous studies, we did not find any evidence that night shiftwork results in an increase in serum PSA levels. Further research and consistent results are needed to elucidate the association between night shiftwork and the effect on the prostate.

Collective exposure to lead from an approved natural product-derived drug in Korea

BACKGROUND: In Asian countries, including Korea, lead poisoning caused by traditional herbal medicines is often observed in the clinic. However, there have been no reports thus far of lead poisoning caused by drugs that were approved by the Korea Food and Drug Administration (KFDA). Here, we describe seven patients who ingested a problematic natural product-derived drug (NPD). CASE PRESENTATION: In July 2018, seven patients visited a university hospital after ingesting an NPD, S. capsules. These patients complained of various symptoms, and their blood lead levels (BLLs) were elevated relative to those of the general population (arithmetic mean: 19.5 ± 11.6 µg/dL, range: 6.28–35.25 µg/dL). The total doses and BLLs were directly proportional to each other among the patients (r = 0.943, p = 0.001). After the patients discontinued drug intake, their BLLs decreased gradually. The capsule was confirmed to contain lead above the standard value (arithmetic mean: 2,547 ± 1,821.9 ppm). CONCLUSION: This incident highlights the need to strengthen standards for the management of NPD ingredients in Korea. NPDs are more likely to be contaminated than other drugs. Thorough management by the KFDA is essential to prevent a recurrence. Moreover, systematic health care is needed for many patients who have taken problematic NPDs.

A Case of Severe Lead Poisoning with Basophilic Stippling Teardrop Cell

No abstract available.

Acute radiation syndrome in a non-destructive testing worker: a case report

BACKGROUND: In Korea, there were repeated radiation exposure accidents among non-destructive testing workers. Most of the cases involved local injury, such as radiation burns or hematopoietic cancer. Herein, we report a case of acute radiation syndrome caused by short periods of high exposure to ionizing radiation. CASE PRESENTATION: In January 2017, Korea Information System on Occupational Exposure (KISOE) found that a 31-year-old man who had worked in a non-destructive testing company had been overexposed to radiation. The patient complained of symptoms of anorexia, general weakness, prostration, and mild dizziness for several days. He was anemic. The venous injection areas had bruises and bleeding tendency. Blood and bone marrow testing showed pancytopenia and the patient was diagnosed with acute radiation syndrome (white blood cells: 1400/cubic mm, hemoglobin: 7.1 g/dL, platelets: 14000/cubic mm). He was immediately prohibited from working and blood transfusion was commenced. The patient’s radiation exposure dose was over 1.4 Gy (95% confidence limits: 1.1–1.6) in lymphocyte depletion kinetics. It was revealed that the patient had been performing non-destructive tests without radiation shielding when working in high places of the large pipe surface. CONCLUSIONS: Exposure prevention is clearly possible in radiation-exposed workers. Strict legal amendments to safety procedures are essential to prevent repeated radiation exposure accidents.

Insomnia and hearing impairment among occupational noise exposed male workers

BACKGROUND: The aim of this study was to investigate the association between insomnia and hearing impairment among workers exposed to occupational noise. METHODS: This study included 809 male workers exposed to occupational noise. The participants underwent audiometric testing, and their insomnia was examined based on the Insomnia Severity Index test. Hearing impairment was defined as hearing threshold >25 dB hearing level in the range of 1–4 kHz. RESULTS: According to analysis of covariance, it was observed that pure tone audiometry thresholds at 1–2 kHz in the right ear and at 1 kHz in the left ear were significantly higher among workers with insomnia compared to those with no insomnia. Multiple logistic regression analysis of insomnia for hearing impairments was performed, which showed the odds ratio was 1.806 (95% confidence intervals: 1.022–3.188, p = 0.042) after adjustment for age, working period, noise level, snoring, use of protection devices, diabetes mellitus, hypertension, smoking, alcohol consumption, regular exercise, waist circumference, total cholesterol, triglyceride and high density lipoprotein cholesterol. CONCLUSION: Insomnia could be associated with hearing impairment in workers who are exposed to occupational noise. Additionally, insomnia may be associated with decreased hearing at low frequencies. Especially, more efforts are required to improve the quality of sleep for workers who are exposed to loud occupational noise. Further well- designed prospective studies are needed to clarify the relationship between insomnia and hearing impairment.

Lead Poisoning at an Indoor Firing Range

In March 2014, a 39-year-old Korean male presented with a 6-month history of various nonspecific symptoms including dizziness, fatigue, asthenia, irritability, elevated blood pressure, palpitation, eyestrain, and tinnitus. His occupational history revealed that he had been working as an indoor firing range manager for 13 months; therefore, he was subjected to a blood lead level (BLL) test. The test results showed a BLL of 64 µg/dL; hence, he was diagnosed with lead poisoning and immediately withdrawn from work. As evident from the workplace environmental monitoring, the level of lead exposure in the air exceeded its limit (0.015–0.387 mg/m³). He received chelation treatment with calcium-disodium ethylenediaminetetraacetic acid (1 g/day) for 5 days without any adverse effects. In the follow-up results after 2 months, the BLL had decreased to 9.7 µg/dL and the symptoms resolved. This report represents the first occupational case of lead poisoning in firing ranges in Korea, and this necessitates institutional management to prevent the recurrence of poisoning through this route. Workplace environmental monitoring should be implemented for indoor firing ranges, and the workers should undergo regularly scheduled special health examinations. In clinical practice, it is essential to question the patient about his occupational history.

Occupational Lead Exposure from Indoor Firing Ranges in Korea

Military personnel often use ammunitions that contain lead. The present study aimed to identify the risks for lead exposure and lead poisoning among workers at indoor firing ranges. A special health examination, including blood lead level (BLL) testing, was performed for all 120 workers at the indoor firing ranges of the Republic of Korea's Air Force, Navy, and Armed Forces Athletic Corps. The overall mean BLL was 11.3 ± 9.4 µg/dL (range: 2.0-64.0 µg/dL). The arithmetic mean of the BLL for professional shooters belong to Armed Forces Athletic Corps was 14.0 ± 8.3 µg/dL, while those of shooting range managers and shooting range supervisors were 13.8 ± 11.1 µg/dL and 6.4 ± 3.1 µg/dL, respectively. One individual had a BLL of 64 µg/dL, and ultimately completed chelation treatment (with CaNa2-ethylenediaminetetraacetic acid) without any adverse effects. These findings indicate that indoor firing range workers are exposed to elevated levels of lead. Therefore, when constructing an indoor firing range, a specialist should be engaged to design and assess the ventilation system; and safety guidelines regarding ammunition and waste handling must be mandatory. Moreover, workplace environmental monitoring should be implemented for indoor firing ranges, and the workers should undergo regularly scheduled special health examinations.

Comparison of anxiety and depression status between office and manufacturing job employees in a large manufacturing company: a cross sectional study

BACKGROUND: The aim of this study was to investigate whether type of work is associated with anxiety and depression using the Hospital Anxiety and Depression Scale (HADS). Additionally, we investigated the impact of number of working hours on anxiety and depression. METHODS: A total of 1774 workers participated and completed the HADS to determine their levels of anxiety and depression. All subjects were employed at one of two manufacturing plants for the same company. Of all participants, 222 were employed in office jobs and 1552 in manufacturing jobs. RESULTS: Results of multivariate logistic regression analysis including age, sex, body mass index, smoking status, alcohol consumption, regular exercise, factory region, and working hours, indicated that employment in an office job was associated with a 2.17-fold increase in the odds of anxiety compared to a manufacturing job (odds ratio [OR] = 2.17; 95 % confidence interval [CI], 1.24–3.80). Office jobs were also associated with a 1.94-fold increase in the odds of depression (OR = 1.94; 95 % CI, 1.34–2.82). In addition, number of hours worked was significantly associated with depression, and working hours significantly modified the effect of office job employment on the risk of depression. CONCLUSIONS: Office job workers had higher levels of anxiety and depression than those working in manufacturing jobs. Our findings suggest that occupational physicians should consider the organizational risks faced by office job employees, and consider the differences in psychological health between office and manufacturing job workers when implementing interventions.

Case series of keratitis in poultry abattoir workers induced by exposure to the ultraviolet disinfection lamp

BACKGROUND: An outbreak of eye diseases occurred among workers at a poultry abattoir in South Korea from December 2012 to June 2013. An epidemiological investigation of the causative agent was conducted. The workers were given a special health examination and workplace environmental monitoring was performed. Workers with ocular symptoms subsequently underwent an ophthalmic examination. CASE PRESENTAION: From a total of 41 workers, 26 (63.4 %) were diagnosed with keratoepitheliopathy by ophthalmic examination. Environmental monitoring of the workplace revealed that the ultraviolet (UV) apron-disinfection lamp had not been turning off at the set times, and so the workers’ faces had been exposed to UV radiation. Effective radiation dose measurement showed a UV-B exposure of 7-30 μW/cm2, and a UV-C exposure of 40-200 μW/cm2; both values exceed the occupational exposure limits. The outbreak ceased after the lamp was repaired. CONCLUSIONS: This case shows that inappropriate use of the UV disinfection lamp can cause mass photokeratitis. In order to prevent this, the UV disinfection lamp must be checked regularly, workers must be educated on the health effects of UV radiation, and appropriate eye protection must be worn.

Respiratory Syncytial Virus Outbreak in the Basic Military Training Camp of the Republic of Korea Air Force / 예방의학회지

OBJECTIVES: An outbreak of acute febrile illness occurred in the Republic of Korea Air Force boot camp from May to July 2011. An epidemiological investigation of the causative agent, which was of a highly infective nature, was conducted. METHODS: Throat swabs were carried out and a multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) assay was performed to identify possible causative factors. RESULTS: The mean age of patients who had febrile illness during the study period was 20.24 years. The multiplex RT-PCR assay identified respiratory syncytial virus (RSV) as the causative agent. The main symptoms were sore throat (76.0%), sputum (72.8%), cough (72.1%), tonsillar hypertrophy (67.9%), and rhinorrhea (55.9%). The mean temperature was 38.75degreesC and the attack rate among the recruits was 15.7% (588 out of 3750 recruits), while the mean duration of fever was 2.3 days. The prognosis was generally favorable with supportive care but recurrent fever occurred in 10.1% of the patients within a month. CONCLUSIONS: This is the first epidemiological study of an RSV outbreak that developed in a healthy young adult group. In the event of an outbreak of an acute febrile illness of a highly infective nature in facilities used by a young adult group, RSV should be considered among the possible causative agents.

Serum prostate-specific antigen levels and type of work in tire manufacturing workers

OBJECTIVES: This study measures serum prostate-specific antigen (PSA) levels in tire-manufacturing workers, and attempts to find occupational or non-occupational factors that related to their PSA levels. METHODS: A total of 1,958 healthy male workers (1,699 were production workers and 259 were office workers) took PSA measurement for analysis. RESULTS: After adjusting for age, body mass index, hypertension, regular exercise, alcohol drinking and smoking, which were significantly related to serum PSA levels or known related factors of serum PSA levels, the geometric mean PSA levels were significantly high in the office workers (p = 0.017), the older age group (p or =4.0 (OR 7.73, 95% CI: 2.78-21.46) or 2.5 ng/mL (OR 2.74, 95% CI: 1.49-5.08). After stratifying by age and adjusting aforementioned covariates, office workers 50 years of age and older had the significantly higher geometric mean PSA levels (p = 0.017) and were more likely to have a serum PSA level of > or =4.0 ng/mL (OR 12.90, 95% CI: 3.65-45.64) or 2.5 ng/mL (OR 3.90, 95% CI: 1.64-9.25) than production workers 50 years of age and older. CONCLUSIONS: This study showed that serum PSA levels were significantly higher among the group with hypertension or the group of individuals that did not exercise regularly or group of office workers who were considered to have lesser physical activities.

Seroprevalence of Respiratory Syncytial Virus IgG among Healthy Young Adults in Basic Training for the Republic of Korea Air Force

This investigation enrolled 570 healthy young males gathered from all over the country for military service at the Republic of Korea Air Force boot camp. It confirmed RSV IgG seroprevalence by utilizing the enzyme immunoassay method just prior to undergoing basic training. The mean age of this study was 20.25+/-1.34 yr old. The results of their immunoassay seroprofiles showed that 561 men (98.4%) were positive, 2 (0.4%) were negative and 7 (1.2%) were equivocal belonging to the grey zone. It was confirmed that RSV is a common respiratory virus and RSV infection was encountered by almost all people before reaching adulthood in Korea. Nine basic trainees belonging to the RSV IgG negative and equivocal grey zone categories were prospectively observed for any particular vulnerability to respiratory infection during the training period of two months. However, these nine men completed their basic training without developing any specific respiratory illness.

Analysis of the Change of Health Status Among the Republic of Korea Air Force Soldiers During Military Service / 예방의학회지

OBJECTIVES: The aim of this study was to investigate whether the health status of Republic of Korea Air Force (ROKAF) soldiers changed after one year of military service. METHODS: We selected 483 ROKAF soldiers from the 11 749 recruits who participated in the 2011 physical examination. The selected soldiers underwent another physical examination in 2012 for advancement to senior airman. Data from 2011 and 2012 were merged. To collect data on lifestyle, a questionnaire was sent to all included subjects via the military intranet e-mail service. RESULTS: The percentage of recruits with an abnormal alanine transaminase level (normal range or =25 kg/m2) decreased from recruitment (20.5%) to the following year (10.4%). There was a significant change in mean duration of exercise carried out each day before (0.8+/-1.3 hours) and after (1.0+/-0.7 hours) joining the ROKAF service. CONCLUSIONS: These ROKAF soldiers were generally in good health before and after joining the armed service. After one year of military service, the health status of most soldiers improved, especially with respect to body mass index and alanine transaminase level.

Comparison of Cardiovascular Disease Status Between Large Scale Industry Office and Self Employed Male Workers / 대한산업의학회지

OBJECTIVES: The aim of this study is to compare the cardiovascular disease status between large scale industry office and self employed male workers who have gaps in their intensive health management. METHODS: The cross sectional study was carried out with subjects composed of 244 shipyard office male workers and 381 self employed male workers, aged 30 to 55 years. They were given a health exam in a general hospital from January 2007 to June 2009. Information was based on data from self-administered questionnaires, physical examination and laboratory results on blood samples. The degree of coronary artery calcification and stenosis was evaluated by a 64 channel multi-detector computed tomography angiography. RESULTS: The prevalence of hypertension(p<0.01) and diabetes mellitus(p=0.02) and waist circumference(p<0.01) was significantly lower in the shipyard office workers than in self employed workers. Proper drinking(p<0.01) was more commmon in shipyard office workers. The rates of coronary artery calcification and stenosis were estimated to be 18.4% and 11.5% respectively for shipyard office workers and were significantly lower than the 26.5% and 21.5% for self employed workers. After adjustment for age, the probability of coronary artery stenosis in shipyard office workers was lower than in self employed workers (OR=0.56, 95% CI=0.35~0.90). CONCLUSIONS: The study results verified the benefits of a health promotion and intervention program and the healthy worker effect for cardiovascular diseases. More specifically, it verified the benefits regarding coronary artery stenosis in large scale industry office workers. This result should encourage the establishment of health promotion programs and the study of occupational epidemiology.