• 한국산업보건학회지
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• 제32권4호
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• pp.435-448
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• 2022

Objectives: As the time spent wearing masks has increased with spread of COVID-19, various research related to masks have been reported. However, there are still few experiments on the physiological response of the body to wearing industrial dust masks in South Korea. Considering the actual working hours at the work site, it is necessary to investigate the comfort of industrial dust masks. Therefore, this study aims to confirm the change in subjective discomfort level according to the wearing time for industrial dust masks in South Korea that have been certified for safety by KCS. Methods: This study evaluated subjective discomfort level over four hours. The experimental conditions were five types: not worn (control group), special grade, first grade, second grade (with valve), and second grade (without valve). The subjective discomfort levels were classified for breathing, warmth (body and face) and wetness (body and face). Subjects recorded their discomfort level on a checklist every one hour. Results: In special grade and second grade (without valve), the discomfort level in terms of breathing, warmth (face), and wetness (face) was significantly higher than that of the control group. However, the effects of all kinds of industrial dust masks on the discomfort level in the body were low. Conclusions: Since this study was conducted on subjects working in an office with a comfortable working environment, it is difficult to apply it to workers at actual industrial sites. However, it is considered meaningful as the first clinical study to evaluate the subjective level of discomfort over a long time for domestic industrial dust masks that have been certified for safety by KCS.

• 한국산업보건학회지
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• 제33권4호
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• pp.403-411
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• 2023

Objectives: Formalin is used as an anthelmintic in farms where flounder are raised. In this study, we aim to identify formaldehyde exposure levels for aquaculture industry workers and provide basic data for managing formaldehyde exposure. Methods: Exposure levels of formaldehyde in the air, including formalin spraying operations, were assessed separately for personal and area samples. In addition, considering the formalin administration method, dermal exposure to the hands was estimated when administering the chemical, and dermal exposure to the legs during water tank work was estimated by collecting water in the water tank and evaluating the amount of formaldehyde remaining. Finally, the respiratory exposure level and the estimated dermal exposure level were added to derive the total exposure level and compared with the maximum allowable human dose. Results: As a result of the airborne evaluation, the formaldehyde concentration of the worker (1 person) who performed the formalin spraying and flounder sorting was 33.61 ppb, and the arithmetic mean of formaldehyde concentrations of the workers (3 people) who only performed the flounder sorting was 3.28 ppb (range: 2.25-4.89 ppb). In the case of dermal exposure, when spraying formalin once, the amount was estimated to be 0.33-2.62 mg when wearing protective gear and 3.27-26.12 mg when not wearing it. Conclusions: There was a difference in the formaldehyde exposure level of workers depending on their operation of handling formalin and whether or not protective gear was worn. In particular, because the level of formaldehyde exposure due to dermal exposure can be significant, there is a need to improve formalin administration methods in a way that avoids skin contact as much as possible.

• 한국산업보건학회지
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• 제34권1호
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• pp.48-56
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• 2024

Objectives: The coronavirus pandemic that began in 2019(COVID-19) has been one of the worst pandemics of the 21st century. Masks have been used to prevent COVID-19, but there are currently no standards for the long-term use of masks in the Republic of Korea. This study was conducted to assess the microbiological safety of KF94(Korea Filter 94) disposable face masks according to wearing duration by evaluating the bacterial filtration efficiencies of masks worn by research participants. Methods: A commercially available KF94 mask certified by the Ministry of Food and Drug Safety(MFDS) in the Republic of Korea was selected as the test mask. The research participants(n = 15) wore masks for the durations of one, three, and seven days. Participants also reported several parameters, including wearing time, makeup frequency, and storage. Bacterial filtration efficiencies of the worn masks were measured by a mask bioaerosol filtration tester. Staphylococcus aureus(S. aureus) was used as the test bacteria and quantitatively measured through the cultivation method. Then, bacterial filtration efficiency was calculated using the formula suggested by the MFDS. Results: All worn masks showed over 99.98% of mean bacterial filtration efficiency for S. aureus. There were no significant differences among bacterial filtration efficiencies of face masks according to wearing duration. There was also no significant difference among bacterial filtration efficiencies among participants. There was no correlation between the results of bacterial filtration efficiencies and reported parameters from participants. Conclusions: In the absence of significant external damage to the mask, the bacterial filtration efficiency of the mask can be maintained even after seven days of wearing. This result suggests that KF94 masks certified by the MFDS can be used repeatedly for about a week without loss of bacterial filtration efficiency.

• 한국산업보건학회지
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• 제34권1호
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• pp.57-66
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• 2024

Objective: Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow obstruction that is only partly reversible, inflammation in the airways, and systemic effects. This study aimed to investigate the association between low peripheral oxygen saturation levels (SpO₂), and composite indices predicting death in male patients with (COPD). Method: A total of 140 participants with post-bronchodilator FEV₁/FVC ratio less than 0.7 were included. Three composite indices (ADO, DOSE, BODEx) were calculated using six variables such as age (A), airflow obstruction (O), body mass index (B), dyspnea (D), exacerbation history (E or Ex), and smoking status (S). Severity of airflow limitation was classified according to Global Initiative for Obstructive Lung Disease (GOLD) guidelines. SpO₂ was measured by pulse oximetry, and anemia and iron deficiency were assessed based on blood hemoglobin levels and serum markers such as ferritin, transferrin saturation, or soluble transferrin receptor. Results: Participants with low SpO₂ (<95%) showed significantly lower levels of %FEV₁ predicted (p=0.020) and %FEV₁/FVC ratio (p=0.002) compared to those with normal SpO₂ levels. The mMRC dyspnea scale (p<0.001) and GOLD grade (p=0.002) showed a significant increase in the low SpO₂ group. Receiver Operating Characteristic analysis revealed higher area under the curve for %FEV₁ (p=0.020), %FEV₁/FVC(p=0.002), mMRC dyspnea scale (p=0.001), GOLD grade (p=0.010), ADO (p=0.004), DOSE (p=0.002), and BODEx (p=0.011) in the low SpO₂ group. Conclusion: These results suggest that low SpO₂ levels are related to increased airflow limitation and the composite indices of COPD.

• 한국산업보건학회지
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• 제34권1호
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• pp.77-84
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• 2024

Objectives: Interventions promoting physical exercise and healthy habits in workplaces have been shown to be effective in reducing risk factors for metabolic syndrome. This study was conducted to examine the effects of an individualized conditioning exercise program of IT company office workers with or at higher risk of metabolic syndrome. Methods: A total of 444 IT company office workers with or at higher risk of metabolic syndrome participated in a 3-month conditioning exercise program. Body composition data using bioelectrical impedance analysis and cardiopulmonary data using cardiopulmonary exercise testing from 53 individuals (mean age: 34.8 ± 7.1 years, sex : 21% female, height : 170.4 ± 6.8 cm, weight : 75.2±12.2 kg, body mass index : 25.8±3.3 kg/m²) who have successfully completed pre-test, intervention, and post-test were analyzed. The 12 weeks intervention encompassed: (1) health counseling (2) supervised exercise(endurance-based, aerobic exercise, or circuit training once a week for 50 minutes at heart rate reserve(HRR) of 77-95%) (3) self-directed exercise and biweekly health screening checks. Results: The results indicated a significant decrease in body weight, body fat mass and body mass index, respectively. Moreover, VO₂peak, AT VO₂ and AT Time significantly improved, respectively. Resting blood pressure(SBP/DBP) showed positive changes but were not statistically significant. We observed the correlation between characteristics of participants and rate of changes in cardiopulmonary outcomes of participants, there are no significant correlation. These results indicate positive changes in body composition and cardiorespiratory fitness parameters following individualized conditioning exercise program. Conclusions: Individualized workplace exercise program for preventing metabolic syndrome can lead to improvements in body composition and cardiorespiratory fitness.

• 치위생과학회지
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• 제4권1호
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• pp.13-20
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• 2004

치과위생사의 효율적인 건강관리와 건강증진을 위한 기초 자료로서 활용하고자 문헌과 자료를 조사하고 전국 치과 병, 의원에 종사하는 치과위생사 160명을 대상으로 2003년 6월부터 10월까지 약 5개월 동안 의료 이용 행태에 관한 설문조사를 실시하여 분석한 결과 다음과 같은 결론을 얻었다. 1. 직업과 관련된 건강 교육 경험 여부를 살펴본 결과, 교육의 경험이 없는 치과위생사가 83.1%로 가장 많았고, 근무 형태에 따라(p<0.05) 통계적으로 유의미한 차이를 보였다. 2. 직장 내 건강 검진 실태를 살펴본 결과, 건강 검진의 필요성에 대해서는 98.6%가 필요하다고 인식하였고, 건강 검진 실시 여부에 대해서는 56.3%가 건강검진의 경험이 있는 것으로 조사되었으며, 연령에 따라(p<0.01), 결혼상태에 따라(p<0.01), 근무형태에 따라(p<0.01), 근무경력에 따라(p<0.01), 연간수입에 따라(p<0.01) 통계적으로 유의미한 차이를 보였다. 3. 치과위생사로의 재직 후 병원 이용실태를 살펴본 결과, 병원 입원 경험이 없다고 응답한 치과위생사가 85.6%로 가장 많았고, 연령에 따라(p<0.05), 근무형태에 따라(p<0.05), 근무경력에 따라(p<0.01), 연간수입에 따라(p<0.05) 통계적으로 유의미한 차이를 보였으며, 외래 진단 경험은 없다고 응답한 치과위생사가 51.9%로 나타났고, 근무경력에 따라(p<0.01) 통계적으로 유의미한 차이를 보였다. 4. 가벼운 질병에 대한 대처 방법으로 약국을 찾는 경우가 34.4%로 가장 많았고, 다음으로 의원 및 병원 방문이 32.5%로 나타났으며, 보약 복용 경험에 대해서는 복용 경험이 없다고 응답한 경우가 68.1%로 나타났고, 연령에 따라(p<0.01), 근무경력에 따라(p<0.05), 연간수입에 따라(p<0.01) 통계적으로 유의미한 차이를 보였다.

• Journal of Preventive Medicine and Public Health
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• 제23권3호
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• pp.275-284
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• 1990

To obtain the useful information for the status of working environment and health management of workers in manufacturing industries, comparision of results on the status of working environmental and health management of workers for 32 manufacturing industries in Chunan area from 1988 to 1989 was carried out. The results were as follows : 1. The rate of over-PEL (Permissible Exposure Limit) to for hazardous factors decreased significantly 23.5% in 1988, 18.3% in 1989 (p<0.05) and, the highest rate of over-PEL was the stone and sand handling industry, the highest rate of over-PEL was the dusty workplace as 38.5% in 1988, 35.2% in 1989. 2. The rate of workers exposed to hazardous factors in 1988 and in 1989 was 22.4% respectively, the rate of workers checked up special health examination was 40.1% in 1988, 75.3% in 1989. In stone and sand handling and medicochemical industries, none of workers exposed to hazardous factors was subjected to special health examination in 1988, but 75% of workers exposed to hazardous factors had checked up in 1989. 3. The 6 industries appointed as part-time factory physician among 17 industries which were supposed to have factory physician according to the Safety and Healthy Act of Korea, 6 out of 24 industries only appointed industrial hygienist, furthermore 4 out of 6 hygienists had another duty in addition to occupational hygiene itself.

• 한국환경보건학회지
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• 제42권2호
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• pp.118-125
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• 2016

Objectives: The traditional type of residence in used in Mongolia, called a ger, is an important residential form and applies coal combustion for cooking and heating. The combustion of coal in ger is the major source of indoor air pollution. The purposes of this study were to measure indoor air pollution in ger and determine the effect of cooking and heating activities. Methods: Indoor temperature, relative humidity, particulate matter less than $2.5{\mu}m$ ($PM_{2.5}$) and black carbon (BC) were continuously measured for 24 hours in eight ger. The measurements were conducted in January or February 2015. Heavy metals in $PM_{2.5}$ filter samples were analyzed by ICP-MS. Results: Average indoor temperature and relative humidity were $19.6{\pm}4.6^{\circ}C$ and $21.4{\pm}5.2%$, respectively. The average indoor $PM_{2.5}$ concentration in the eight ger was $119.8{\mu}g/m^3$ and ranged from 69.4 to $202.7{\mu}g/m^3$. The peak concentrations of $PM_{2.5}$ and BC during cooking and heating periods were several times higher than the 24- hour average concentration. Conclusion: The major contributor to indoor $PM_{2.5}$ and BC concentrations in the ger was coal combustion for cooking and heating.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8149-8153
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• 2016

An oncopathological state assessment was conducted among adults, children and teenagers in Aktobe region for 2004-2013. Overall the burden of mortality was in the range of 94.8-100.2 per 100,000 population, without any obvious trend over time. Ranking by pathology, the highest incidences among women were registered for breast cancer (5.8-8.4), cervix uteri (2.9-4.6), ovary (2.4-3.6) and corpus uteri, stomach, esophagus, without any marked change over time except for a slight rise in cervical cancer rates. In males, the first place in rank was trachea, bronchus and lung, followed by stomach and esophagus, which are followed by bladder, lymphoid and hematopoietic tissues pathology. Agian no clear trends were apparent over time. In children, main localizations in cancer incidence blood (acute lymphocytic leukemia, lymphosarcoma, acute myeloid leukemia, Hodgkin's disease), brain and central nervous system, bones and articular cartilages, kidneys, and eye and it's appendages, in both sexes. Similarly, in young adults, the major percentage was in blood and lymphatic tissues (acute myeloid leukemia, acute lymphocytic leukemia, Hodgkin's disease) a significant percentage accruing to lymphosarcoma, lymphoma, other myeloid leukemia and hematological malignancies as well as tumors of brain and central nervous system, bones and articular cartilages. This initial survey provides the basis for more detailed investigation of cancer epidemiology in Aktobe, Kazakhstan.

• Asian Pacific Journal of Cancer Prevention
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• 제16권17호
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• pp.7613-7618
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• 2015

Childhood acute lymphoblastic leukemia (ALL) is one of the most common hematologic malignancies which accounts for one fourth of all childhood cancer cases. Exposure to environmental factors around the time of conception or pregnancy can increase the risk of ALL in the offspring. This study aimed to evaluate the influence of prenatal and postnatal exposure to high voltage power lines on the incidence of childhood ALL. It also examines the role of various factors such as environmental factors and alpha-amylase as a marker in the development of leukemia.This cross-sectional case control study was carried out on 22 cases and 100 controls who born and lived in low socioeconomic families in Tehran and were hospitalized for therapeutic purposes in different hospitals ofrom 2013-2014. With regard to the underlying risk factors; familial history and parental factors were detected as risk factors of ALL but in this age, socioeonomic and zonal matched case control study, prenatal and childhood exposure to high voltage power lines was considered as the most important environmental risk factor (p=0.006, OR=3.651, CI 95% 1.692-7.878). As the population study was from low socioeconomic state, use of mobiles, computers and microwaves was negligible. Moreover prenatal and postnatal exposure to all indoor electrically charged objects were not detected as significant environmental factors in the present study. This work defined the risk of environmental especially continuous pre and postnatal exposure to high voltage power lines and living in pollutant regions through the parents or children as well as the previously described risk factors of ALL for the first time in low socioeconomic status Iranian population.