Evaluation of Temporal Trends of Lead Exposure in Korean Workers Using Workplace Monitoring Data

Background@#Lead, which is widely used in various industrial settings, is a major health hazard for manufacturing workers. Therefore, control of lead exposure has been implemented in an effort to prevent lead-related health problems. In this study, our aim was to evaluate temporal trends in occupational lead exposure in Korean lead workers using data from monitoring of workplace exposure. @*Methods@#A nationwide work environment monitoring database, data from a work environment monitoring institution, and data extracted from a review paper were utilized. Different versions of standard industrial classification codes were aligned with the 10th Korean Standard Industrial Classification, which is generally consistent with the 4th revision of the International Standard Industrial Classification. The multiple data sources were combined and temporal trends over the period from 1994–2021 were estimated. In addition, separate estimation of temporal trends in the storage battery manufacturing industry over the period from 1987–2021 was also performed. @*Results@#A total of 444,296 personal airborne lead measurements were used for the estimation process. The temporal trends in occupational exposure to lead declined by −6% annually over the study period. In particular, levels of lead exposure in the storage battery manufacturing industry showed a steeper decline of −12% annually. @*Conclusions@#Findings of our study showed that occupational exposure to lead declined over the period from 1994 to 2021 in Korea. However, adverse effects of exposure to lead on health should be regarded with caution. The results will be useful in conduct of epidemiological studies examining lead-related effects on health.

Hazard Levels of Cooking Fumes in Republic of Korea Schools

Background@#and PurposeIn 2021, lung cancer in school food workers was first recognized as an occupational cancer. The classification of the carcinogenicity of cooking fumes by International Agency for Research on Cancer (IARC) was based on Chinese epidemiological data. This study aimed to determine the hazard levels of school cooking fumes in Korea. @*Materials and Methods@#Based on public school cafeterias in one area, 25 locations were selected for the survey according to the number per school type, ventilation states, and environmental pre-assessments of cafeterias. Two inside cooking areas using a heat source and one outside cooking area were selected as control measurement points. Measurements of CO, CO2, polycyclic aromatic hydrocarbons (PAHs), and total volatile organic compounds (TVOCs), including benzene, formaldehyde, and particulate matter (PM10, PM2.5, PM1, respectively), were taken. The concentrations and patterns of each substance in the kitchens were compared with the outdoor air quality.ResultKnown carcinogens, such as the concentrations of PAHs, formaldehyde, TVOC (benzene), and particulate matter in school cooking fumes, were all detected at similar or slightly higher levels than those found outside. Additionally, substances were detected at relatively low concentrations compared to the Chinese cooking fumes reported in the literature. However, the short-term exposure to high concentrations of CO (or composite exposure with CO2) and PM2.5 in this study were shown. @*Conclusion@#The school cooking fumes in South Korea was a relatively less harmful than Chinese cooking fumes, however short-term, high exposure of toxic substances can cause a critical health effect.

A Pilot Establishment of the Job-Exposure Matrix of Lead Using the Standard Process Code of Nationwide Exposure Databases in Korea

Background@#The purpose of this study is to construct a job-exposure matrix for lead that accounts for industry and work processes within industries using a nationwide exposure database. @*Methods@#We used the work environment measurement data (WEMD) of lead monitored nationwide from 2015 to 2016. Industrial hygienists standardized the work process codes in the database to 37 standard process and extracted key index words for each process. A total of 37 standardized process codes were allocated to each measurement based on an automated key word search based on the degree of agreement between the measurement information and the standard process index. Summary statistics, including the arithmetic mean, geometric mean, and 95th percentile level (X95), was calculated according to industry, process, and industry process. Using statistical parameters of contrast and precision, we compared the similarity of exposure groups by industry, process, and industry process. @*Results@#The exposure intensity of lead was estimated for 583 exposure groups combined with 128 industry and 35 process. The X95 value of the “casting” process of the “manufacture of basic precious and non-ferrous metals” industry was 53.29 μg/m3, exceeding the occupational exposure limit of 50 μg/m3. Regardless of the limitation of the minimum number of samples in the exposure group, higher contrast was observed when the exposure groups were by industry process than by industry or process. @*Conclusion@#We evaluated the exposure intensities of lead by combination of industry and process. The results will be helpful in determining more accurate information regarding exposure in lead-related epidemiological studies.

Estimation of Lead Exposure Intensity by Industry Using Nationwide Exposure Databases in Korea

Background@#In a previous study, we estimated exposure prevalence and the number of workers exposed to carcinogens by industry in Korea. The present study aimed to evaluate the optimal exposure intensity indicators of airborne lead exposure by comparing to blood lead measurements for the future development of the carcinogen exposure intensity database. @*Methods@#Data concerning airborne lead measurements and blood lead levels were collected from nationwide occupational exposure databases, compiled between 2015 and 2016. Summary statistics, including the arithmetic mean (AM), geometric mean (GM), and 95th percentile level (X95) were calculated by industry both for airborne lead and blood lead measurements. Since many measurements were below the limits of detection (LODs), the simple replacement with half of the LOD and maximum likelihood estimation (MLE) methods were used for statistical analysis. For examining the optimal exposure indicator of airborne lead exposure, blood lead levels were used as reference data for subsequent rank correlation analyses. @*Results@#A total of 19,637 airborne lead measurements and 32,848 blood lead measurements were used. In general, simple replacement showed a higher correlation than MLE. The results showed that AM and X95 using simple replacement could be used as optimal exposure intensity indicators, while X95 showed better correlations than AM in industries with 20 or more measurements. @*Conclusion@#Our results showed that AM or X95 could be potential candidates for exposure intensity indicators in the Korean carcinogen exposure database. Especially, X95 is an optimal indicator where there are enough measurements to compute X95 values.

A case of acute organic solvent poisoning during epoxy coating

BACKGROUND: In the construction industry, maintaining health and safety of workers often challenging. Among the workers at construction sites, painters are at particular risk of respiratory diseases and neurotoxicity. However, in Korea there is weak enforcement of workers' health and safety practices in the construction industry in Korea. Poisonings frequently occur at (semi)closed construction sites. In this study, we report a case of acute organic solvent poisoning during construction site painting. CASE PRESENTATION: A 71-year-old man was found unconscious at a construction site and immediately transferred to the emergency room. The consciousness level was 'stupor state' and the body temperature was hypothermic, at 32 degrees (Celsius). There were no acute brain or cardiac lesions that would have accounted for the faintness. In addition, blood and urine tests did not indicate a cause of loss of consciousness. He had been painting epoxy to waterproof the basement floor before fainting. According to exposure simulation, the patient was overexposed to various organic solvents, such as approximately 316–624 ppm toluene during the work before fainting. Considering the ventilation status of the workplace and the status of no protection, it is considered that exposure through the respiratory tract was considerable. CONCLUSIONS: The patient in this case lost consciousness during the epoxy coating in a semi-enclosed space. It can be judged as a result of acute poisoning caused by organic solvent exposure and considered to be highly related to work environment.

Estimates of the Prevalence, Intensity and the Number of Workers Exposed to Cigarette Smoking across Occupations and Industries in Korea

BACKGROUND: Tobacco smoking affects the incidence of various illnesses such as lung cancer, respiratory diseases, and cardiovascular diseases. In an effort to prevent smoking-related cancers, we aimed to estimate the smoking prevalence, intensity, and number of workers exposed to smoking, which would be specific to the occupational and industrial circumstances in Korea. METHODS: We used the Korean Working Condition Survey (KWCS) and Korea's Census data. Smoking prevalence and intensity were estimated using the KWCS data. The number of smokers was estimated by multiplying smoking prevalence with the number of workers in the occupation or industry. Smoking prevalence, intensity, and number of smokers were estimated for major, sub-major, and minor groups of occupation and industry. RESULTS: Of the total labor force in 2010, 52.66% of men and 5.24% of women workers were estimated to be current smokers. Men workers smoked 15.42 cigarettes/day, and women workers 11.29 cigarettes/day. In terms of occupation, “craft and related trades workers” demonstrated the highest smoking prevalence (52.24%). “Managers” smoked the highest number of cigarettes (16.63 cigarettes/day) and “equipment, machine operating, and assembling workers” comprised the largest number of estimated smokers (1,368,726 workers). In terms of industry, “mining and quarrying” had the highest smoking prevalence (69.27%). Those in “construction” smoked the highest number of cigarettes (17.16 cigarettes/day) and those in “manufacturing” comprised the largest number of estimated smokers (1,629,893 workers). CONCLUSION: Our results may help in setting priorities for smoking prevention-related activities. In addition, these results can be used for epidemiological studies controlling for the effect of smoking by occupation or industry.

The Mental Health and Occupational Characteristic of Horse Stable Hand Workers in Korea

The horse stable hand workers are one of the most important occupations in horse-racing industry. However, suicide problem of the horse stable hand workers in Korea has raised the necessity of new study on how these workers experience mental health problems such as occupational stress and depression in organizational situation. Therefore, this study investigated the occupational stress and depression level of the horse stable hand workers and identified the structural relationship in the horse-racing industry through a detailed interview. A total of 207 horse stable hand workers participated in this study, and occupational stress and depression level were surveyed using the Korean Occupational Stress Scale (KOSS) and Korean version of the Center for Epidemiologic Studies-Depression Scale (CES-D). The results of this study showed that the occupational stress level of horse stable hand workers was higher than the median of Korean population. The significant difference in occupational stress among the detail job grade was also identified. In addition, 34% of the horse stable hand workers showed high risk of depression, and job demand, organizational system, and inappropriate compensation as the subfactors of occupational stress were showed to mainly affect depression. Although there are some limitations according to the field survey, this study also has significant meaning in that it identifies the relationship between the occupational characteristics of the horse stable hand workers and the mental health. It will be necessary to study the diverse organizational situation and individual mental health for new occupations.

Work-related olfactory disorder: a case series and review

BACKGROUND: The olfactory bulb is anatomically exposed and thus can be directly damaged by external stimulation. This can occur as an occupational injury owing to contact with organic solvents or other causes. We present cases of eight patients who sustained occupation-related exposure to potentially toxic substances and later presented with signs and symptoms of anosmia. We examined the occupational and medical characteristics of the patients and evaluated their work-relatedness. CASE PRESENTATION: Case 1: A 50-year-old man performed high-frequency heat treatments for approximately 11 years. He experienced decreased senses for olfaction and taste during the later years culminating in the diagnosis of anosmia after 3 years (high work-relatedness). Case 2: A 54-year-old man whose work involved exposure to various organic solvents, such as spray painting and application of paint and thinners for approximately 4 years, was subsequently diagnosed with anosmia based on rhinorrhea, headache, and loss of olfaction (high work-relatedness). Case 3: A 44-year-old-man who performed spray painting for approximately 17 years developed anosmia (high work-relatedness). Case 4: A 44-year-old man was involved in ship engine cleaning once a month, for approximately 7 h per cleaning session; he was diagnosed with anosmia based on loss of olfaction (low work-relatedness). Case 5: A 41-year-old man worked in ship building block construction for approximately 13 years; anosmia diagnosis was based on loss of olfaction (low work-relatedness). Case 6: A 47-year-old woman performed product inspection and labeling at a plant manufacturing automobile parts; anosmia diagnosis was based on decreased olfaction and taste (low work-relatedness). Case 7: A 50-year-old woman performed epoxy coating in a plant manufacturing automobile parts; anosmia diagnosis was based on diminishing olfaction (low work-relatedness). Case 8: A 57-year-old woman performed cleaning of the area where mobile phone parts were manufactured; anosmia diagnosis was based on diminishing olfaction (low work-relatedness). CONCLUSION: The study results confirmed work-relatedness when the subject was young, and the duration of exposure was long without any other cause of anosmia. Regarding compensation for occupational diseases, work-relatedness can be recognized as a relative concept.

Dermal and neural toxicity caused by acrylamide exposure in two Korean grouting workers: a case report

BACKGROUND: Peripheral neuritis caused by acrylamide is well-known, and many Korean grouting workers are frequently exposed to acrylamide in grouting agents that are injected into cracked concrete. We recently encountered two cases of dermal and neural toxicity in Korean grouting workers with exposure to grouting agents that contained a high concentration of acrylamide. CASE PRESENTATION: The first case involved a 44-year-old man with 8 years of waterproofing experience. The patient developed peeling skin on both hands while grouting, which progressed to systemic neurological symptoms, such as reduced sensory function and strength. The patient was diagnosed with peripheral neuropathy caused by acrylamide exposure, and fully recovered after conservative treatment and withdrawal of exposure to the grouting agent. The second case involved a 34-year-old man with 10 years of grouting experience. The patient initially experienced weakness in both legs, which progressed to weakness in his arms and uncontrolled phonation. After being hospitalized, he was diagnosed with cerebellar ataxia and peripheral neuropathy caused by acrylamide exposure, and was discharged after conservative treatment. Our follow-up investigation revealed that both workers were recently exposed to grouting agents that contained higher concentrations of acrylamide, compared to the agents that they had previously been using. CONCLUSIONS: Both workers had workplace acrylamide exposure through dermal contact plus inhalation of dust and vapor, which led to the neural toxicity and dermatitis. Therefore, government studies are needed to investigate the current status of workplace acrylamide use, and to protect workers from the hazardous effects of using acrylamide-containing grouting agents.

The work-relatedness at a case of acute lymphoblastic leukemia in a radiation oncologist

BACKGROUND: Clinicians who perform radiation therapy (RT) are exposed to radiation, which may negatively affect their health. The present study reports a case of acute lymphoblastic leukemia in a healthcare provider who was exposed to radiation at work; we also present a literature review of this topic. CASE PRESENTATION: A 45-year-old patient, who had been a radiation oncologist and had been exposed to radiation while performing brachytherapy 10 years ago, complained of chest pain and was suspected of having leukemia based on the results of a blood test in an outpatient clinic. He was diagnosed with acute lymphoblastic leukemia, and subsequently underwent chemotherapy. However, the case died during treatment. Through epidemiological investigation, it was found that the case's cumulative exposure dose based on personal exposure and spatial dose measured during the work period was in the range of 6.08–12.15 mSv. CONCLUSIONS: Based on the following considerations, acute lymphoblastic leukemia was highly correlated with the level of radiation to which the case was exposed while performing brachytherapy on patients with cancer. Firstly, the latent period of acute lymphoblastic leukemia in the case closely matched the latency time reported in previous published studies (5–10 years). In addition, numerous studies have reported significantly higher relative risks of cancer among clinicians who perform RT compared with the general population. The case was also atypically exposed to radiation through his hands, despite wearing protective equipment. Lastly, the case's coworkers were also found to have been exposed to high levels of radiation. Investigation into the influence of radiation exposure through atypical routes during RT on the health of clinicians is recommended.