Hydrogen sulfide is a toxic substance that humans can be exposed to occupationally, and cases of hydrogen sulfide poisoning of workers in industrial sites are commonly reported. However, there have been no cases of poisoning of the public due to an unauthorized discharge of wastewater, so it is important to describe this incident.

In a small village in Jeollanam-do, Republic of Korea, accounts of a terrible stench had been reported. A 26-year-old man who lived and worked in a foul-smelling area was taken to the emergency room with a headache, dizziness, nausea, and repeated syncope. A subsequent police and Ministry of Environment investigation determined that the cause of the stench was the unauthorized discharge of 9 tons of wastewater containing hydrogen sulfide through a stormwater pipe while the villagers were sleeping. The patient had no previous medical history or experience of symptoms. Leukocytes and cardiac markers were elevated, an electrocardiogram indicated biatrial enlargement, left ventricular hypertrophy, and corrected QT interval prolongation. Myocardial hypertrophy was detected on a chest computed tomography scan, and hypertrophic cardiomyopathy was confirmed on echocardiography. After hospitalization, cardiac marker concentrations declined, symptoms improved, and the patient was discharged after 7 days of hospitalization. There was no recurrence of symptoms after discharge.

We suspect that previously unrecognized heart disease manifested or was aggravated in this patient due to exposure to hydrogen sulfide. Attention should be paid to the possibility of unauthorized discharge of hydrogen sulfide, etc., in occasional local incidents and damage to public health. In the event of such an accident, it is necessary to have government guidelines in place to investigate health impact and follow-up clinical management of exposed residents.

For health care workers, immune management plays an important role in the protection against infectious diseases. This study investigated the seroprevalence of measles, mumps, rubella, and varicella-zoster in newly employed female nurses.

We conducted a survey on the seroprevalence of measles, mumps, rubella, and varicella-zoster in newly employed female nurses at a university hospital from 2011 to 2019, before the nurses were given their department placements and duty start. Enzyme-linked immunosorbent and chemiluminescence immunoassays were used to detect immunoglobulin G antibodies. We analyzed whether there was a significant difference in seroprevalence depending on the age, birth year, birth season, and region of residence (metropolitan residency: yes or no).

The arithmetic mean ages of the participants were 28.6 ± 4.8, 23.5 ± 3.2, 23.6 ± 3.0, and 26.1 ± 4.5 years for measles, mumps, rubella, and varicella-zoster, respectively. The seropositivity rates were 93.9% (551/587), 60.2% (50/83), 83.3% (3,093/3,711), and 89.5% (978/1,093) for measles, mumps, rubella, and varicella-zoster, respectively. Significant differences in the seroprevalence when assessed according to the age and birth year were noted with measles, while significant differences in the seroprevalence were only noted with rubella and varicella-zoster when assessed according to birth year and age, respectively.

In this study, we identified the levels of antibody prevalence in new female nurses. Considering the seropositivity levels, cost-effectiveness, and convenience for the participants, we recommend that the measles-mumps-rubella vaccination be provided without serologic testing for all new female nurses and the varicella-zoster vaccination only be performed for persons who are negative after serologic testing. And it would be useful if the vaccinations were combined with compulsory worker health examinations, such as the pre-placement health examinations.

Previous studies have shown that morning types are less sensitive to pain. This study aimed to examine the relationship between chronotypes and musculoskeletal problems in workers with musculoskeletal burdens at work.

This cross-sectional study included 119 male production workers from a large automobile manufacturing plant. All the participants worked 2 shifts and worked on the automobile assembly line. Data were obtained using structured questionnaires, including the reduced Morningness-Eveningness Questionnaire (rMEQ), and musculoskeletal symptom questionnaire. Participants with an rMEQ score of 18 points or more were defined as morning-type workers (MTWs). Participants whose scores were less than 18 points were defined as neither-type workers (NTWs).

The arithmetic mean age was 51.8 ± 5.3 years. MTWs and NTWs accounted for 35.3% and 64.7% of the total participants, respectively. Evening- and intermediate-type workers accounted form 6.7% and 58.0% of the participants, respectively. There was no significant difference in the health indicators when the MTW and NTW groups were compared. However, the musculoskeletal symptom questionnaire demonstrated a significant difference between the MTW and NTW groups. In the preceding year, the MTW group had significantly lower musculoskeletal pain and treatment ratios compared to the NTW group (35.7% vs. 62.3%, p = 0.005 and 14.3% vs. 32.5%, p = 0.031, respectively). After adjusting for variables, the odds ratio (OR) for musculoskeletal pain was significantly higher in the NTW group than in the MTW group (OR, 3.112; 95% confidence interval, 1.285–7.535; p = 0.012).

In this study, the musculoskeletal pain ratio was significantly lower for MTWs when compared to NTWs. Chronotypes could play an important role in work-related musculoskeletal disorders. Further, larger-scale, follow-up studies on chronotypes are required to assist in the prevention of musculoskeletal disorders in future.

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.

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.

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).

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.

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.

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.

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.

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.

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).

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).

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.

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.

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.

Exposure prevention is clearly possible in radiation-exposed workers. Strict legal amendments to safety procedures are essential to prevent repeated radiation exposure accidents.

The aim of this study was to investigate the association between insomnia and hearing impairment among workers exposed to occupational noise.

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.

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.

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.

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.

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.

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.

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.

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 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.

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.

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.

A total of 1,958 healthy male workers (1,699 were production workers and 259 were office workers) took PSA measurement for analysis.

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 < 0.001), the group with hypertension (p = 0.046) and the group of individuals that do not exercise regularly (p = 0.015) and the office workers were more likely to have a serum PSA level of ≥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 ≥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.

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.