• Journal of Environmental Health Sciences
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• v.41 no.4
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• pp.231-240
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• 2015

Objectives: Blood mercury levels among adults living in certain areas of the Gyeongsang Provinces have been shown to be very high (Kunwee County $29.6{\mu}g/L$, Yeongcheon-city $26.7{\mu}g/L$). The purpose of this project was to determine mercury exposure levels in schoolchildren and factors related with their mercury levels in high mercury exposure areas identifyed by the 2007 Korea National Environmental Health Survey. Methods: From June to September 2010, 1,097 students from grades 3 to 6 at 19 elementary schools participated in this study, including 294 students from 10 elementary schools in Kunwee County, 529 students from Yeongcheon City, 122 students from two elementary schools in Pohang City, North Gyeongsang Province, and 152 students from two elementary schools in Ulsan Metropolitan City. Biological samples from schoolchildren, including whole blood, urine and hair, were collected to measure total mercury at the time of a health check up. Information about children was collected by questionnaire. Total mercury concentrations in blood were measured using the Direct Mercury Analyzer 80 with the gold-amalgam collection method. Results: The mean mercury levels were $2.70{\mu}g/L$ in 1,091 blood samples, $2.25{\mu}g/g-creat.$ in 820 urine samples and $1.03{\mu}g/g$ in 1,064 hair samples. Blood mercury levels in the schoolchildren was slightly higher than the result of $2.4{\mu}g/L$ from a 2006 survey of elementary school children on exposure and health effects of mercury by the National Institute of Environmental Research. However, 0.3% and 4.5% of participants exceeded the reference level of blood mercury by CHBMII ($15{\mu}g/L$) and the US EPA ($5.8{\mu}g/L$), respectively. The reference level of urine by CHBMII ($20{\mu}g/L$) was exceeded by 0.4% of participants. As factors, residence period in the study areas, residence type, father's education level and income all showed significant associations with mercury level in the biological samples. The number of dental amalgam sides showed an association with urine mercury. Fish intake preference and fish intake frequency were important factors in mercury levels. In particular, intake of shark meat and recent intake of shark meat were associated with higher mercury levels. In this regard, participation in the performance of an ancestral rite showed a relation with higher mercury levels. Conclusion: The intake of shark meat was very important factor to high mercury exposure level. It is recommended to monitor and manage students with high mercury exposures who exceeded CHBM II and EPA guidelines, and include blood mercury testing in the Children's Health check up for this province.

• Clinical and Experimental Reproductive Medicine
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• v.39 no.1
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• pp.1-9
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• 2012

The safety of human exposure to an ever-increasing number and diversity of electromagnetic field (EMF) sources both at work and at home has become a public health issue. To date, many in vivo and in vitro studies have revealed that EMF exposure can alter cellular homeostasis, endocrine function, reproductive function, and fetal development in animal systems. Reproductive parameters reported to be altered by EMF exposure include male germ cell death, the estrous cycle, reproductive endocrine hormones, reproductive organ weights, sperm motility, early embryonic development, and pregnancy success. At the cellular level, an increase in free radicals and $[Ca^{2+}]i$ may mediate the effect of EMFs and lead to cell growth inhibition, protein misfolding, and DNA breaks. The effect of EMF exposure on reproductive function differs according to frequency and wave, strength (energy), and duration of exposure. In the present review, the effects of EMFs on reproductive function are summarized according to the types of EMF, wave type, strength, and duration of exposure at cellular and organism levels.

• Journal of Environmental Health Sciences
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• v.42 no.6
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• pp.430-437
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• 2016

Objectives: The new Chemical Control Act from the Korean Ministry of Environment (2014-259) simply states only in basic phrases that every worker handling the listed chemicals should wear personal protective equipment (PPE) and does not consider the different hazard characteristics of particular chemicals or work types. The purpose of this study was to produce an exposure risk matrix and assign PPE to the categories of this matrix, which would be useful for revising the act to suggest PPE to suit work types or situations. Methods: An exposure risk matrix was made using hazard ranks of chemicals and workplace exposure risks in the previous study. For the 20 categories of exposure risk matrix PPE, levels A, B, C, D as classified by OSHA/EPA were assigned. After 69 hazardous chemicals were divided into 11 groups according to their physiochemical characteristics, respirators, chemical protective clothing (CPC), gloves and footwear were suggested on the basis of the assigned PPE levels. Results: PPE table sheets for the 11 groups were made on the basis of work types or situations. Full facepiece or half-mask for level C was recommended in accordance with the exposure risk matrix. Level A was, in particular, recommended for loading or unloading work. Level A PPE should be worn in an emergency involving hydrogen fluoride because of the number of recent related accidents in Korea. Conclusion: PPE assignment according to the exposure risk matrix made by chemical hazards and work type or situation was suggested for the first time. Each type of PPE was recommended for the grouped chemicals. The research will be usefully used for the revision of the Chemical Control Act in Korea.

• Journal of Food Hygiene and Safety
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• v.23 no.1
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• pp.80-84
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• 2008

Maximum level of hazardous chemicals in foods can be settled after overall investigation of toxicological database, the representative exposure assessment, risk level on the present exposure level, the need of maximum level establishment, making of maximum level scenario proposed under consumer protection and verification of contamination reduction method and review of application efficiency on maximum level for risk management. The maximum level should be needed when the risk value of specific chemical caused by food ingestion was high and chronic human exposure was predicted continuously unless the maximum level exists. The key role of the risk assessment is to improve the efficiency of the risk management to reduce the present risk level and make the risk management policy scientifically by setting the representative result of the risk assessment.

• Journal of radiological science and technology
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• v.47 no.3
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• pp.167-173
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• 2024

This study purpose to establish an appropriate target exposure index(EIT) using dose area product(DAP) and exposure index(EI) based on chest radiography. First, the system response experiment was conducted with radiation quality of RQA5 to compare the dosimetry and dose area product of equipment. Next, EI and DAP were acquired and analyzed while varying the dose in the diagnostic at 70kVp using a human body model phantom. The signal to noise ratio(SNR) of the obtained results was analyzed in the diagnostic with in the diagnostic reference level(DRL) application range. The DRL at percentage 25% had a dose of 0.17 mGy and EI was 83, and at percentage 75% the dose was 0.68 mGy and EI was 344. As the dose increased, the SNR in the subdiaphragm increased. To set the EIT, calibration must first be performed using a dosimeter and set within the DRL range to reflect the needs of the medical institution.

• Journal of Korean Biological Nursing Science
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• v.20 no.3
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• pp.187-195
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• 2018

Purpose: The purpose of this study was to identify associations among the sleep disturbance, fatigue, job stress, and blood and body fluid (BBF) exposure of shift-work nurses. Methods: A total of 299 shift-work nurses from two tertiary hospitals were enrolled in this study. We used the Insomnia Severity Index (ISI), and the Fatigue Severity Scale (FSS), and the Korean Occupational Stress Scale-Short Form (KOSS-SF) to evaluate sleep disturbance, fatigue, and job stress, respectively. The data were analyzed using t-test or chi-squared test and Logistic regression analysis using the SPSS 23.0 program. Results: We found that 43.8% of participants reported BBF exposure over the past year. Splash or exposure to broken skin of BBF were most frequent (56.9%), and followed by needlestick injuries (30.4%) and sharp injuries (12.8%). Age, hospital, working period, level of stress, sleep disturbance ($ISI{\geq}15$), fatigue (FSS $score{\geq}4$), job demand and organizational climate subset in KOSS-SF were significantly associated with BBF exposure in shift-work nurses. In multivariate analysis after adjusting age and hospital, the risk factors of BBF exposure in shift-work nurses were the level of stress and fatigue (FSS $score{\geq}4$). Conclusion: Fatigue and job stress were related to BBF exposure in shift-work nurses. Our results suggest that management of sleep disturbance, fatigue, and high job stress in shift-work nurses is needed to reduce risk of BBF exposure.

• Journal of Environmental Science International
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• v.22 no.1
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• pp.47-57
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• 2013

Studies evaluating the health effects of hazardous air pollutants assume that people's exposure to typical pollutant level is the same as specific regional pollutant level. However, depending on social and demographic factors, time-activity pattern of people can vary widely. Since most people live in indoor environments over 88% of the day, evaluating exposure to hazardous air pollutants is hard to characterize. Objective of this study was to estimate the exposure levels of university students of $NO_2$, VOCs(BTEX) and $PM_{10}$ using the scenarios with time-activity pattern and indoor concentrations. Using data from time-use survey of National Statistical Office in 2009, we investigated time-activity pattern of university students and hourly major action. A total of 1,057 university students on weekday and 640 on weekend spent their times at indoor house 13.04 hr(54.32%), other indoors 7.70 hr(32.06%), and transportation 2.36 hr(9.83%). Indoor environments in which university students spent their times were mainly house and school. Air pollutants concentrations of other indoor environments except house and school such as bar, internet cafe and billiard hall were higher than outdoors, indicating that indoor to outdoor ratios were above 1. According to three types of exposure scenarios, exposure to air pollutants could be reduced by going home after school.

• Journal of Preventive Medicine and Public Health
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• v.45 no.6
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• pp.353-363
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• 2012

Methylmercury is a hazardous substance that is of interest with regard to environmental health, as inorganic mercury circulating in the general environment is dissolved into freshwater and seawater, condensed through the food chain, ingested by humans, and consequently affects human health. Recently, there has been much interest and discussion regarding the toxicity of methylmercury, the correlation with fish and shellfish intake, and methods of long-term management of the human health effects of methylmercury. What effects chronic exposure to a low concentration of methylmercury has on human health remains controversial. Although the possibility of methylmercury poisoning the heart and blood vessel system, the reproductive system, and the immune system is continuously raised and discussed, and the carcinogenicity of methylmercury is also under discussion, a clear conclusion regarding the human health effects according to exposure level has not yet been drawn. The Joint FAO/WHO Expert Committee on Food Additives proposed to prepare additional fish and shellfish intake recommendations for consumers based on the quantified evaluation of the hazardousness of methylmercury contained in fish and shellfish, methylmercury management in the Korea has not yet caught up with this international trend. Currently, the methylmercury exposure level of Koreans is known to be very high. The starting point of methylmercury exposure management is inorganic mercury in the general environment, but food intake through methylation is the main exposure source. Along with efforts to reduce mercury in the general environment, food intake management should be undertaken to reduce the human exposure to methylmercury in Korea.

• Journal of Environmental Health Sciences
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• v.46 no.6
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• pp.676-684
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• 2020

Objectives: In this study, the extent of environmental exposure reduction behavior among the elderly living in Gongju City was identified according to demographic and sociological characteristics of individual health behavior and environmental factors. In addition, the relationship between subjective health knowledge and environmental exposure reduction behavior among the elderly was investigated. Methods: Demographic and sociological factors, subjective health status, environmental factors, and environmental exposure reduction behavior were investigated among 120 elderly people in Gongju City. Through multiple regression analysis, variables with significant relationships with environmental exposure reduction behavior were identified (SPSS ver. 22, IBM, Armonk, NY, USA). The survey (IRB-2018-0096) was conducted over about two weeks (from Dec. 3 to 14, 2018). Results: The extent of practicing environmental exposure reduction behavior by the elderly in Gongju City was high in terms of cleaning, ventilation when cooking food, periodic outdoor activities, and ventilation when smoking. Significant variables were gender, past smoking and current non-smoking, subjective health knowledge, and subjective health status. The most influential variable was subjective health knowledge (β= .411). Conclusion: There was a significant relationship between the level of subjective health knowledge and the level of objective education for health behavior related to the reduction of environmental exposure among the elderly.

• Annals of Occupational and Environmental Medicine
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• v.34
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• pp.43.1-43.11
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• 2022

Background: Polycyclic aromatic hydrocarbons (PAHs) have become common pollutants with industrial development. Although the effect of exposure to PAHs on allergic disease in humans has been evaluated, evidence of an association is sparse. The association between PAH exposure and serum total immunoglobulin E (IgE) levels was evaluated in Korean adults. Methods: In total, this study included 3,269 participants in the Third Korean National Environmental Health Survey (2015-2017). Four urinary PAH metabolites were used to assessed exposure to PAHs: 1-hydroxypyrene, 1-hydroxyphenanthrene, 2-naphthol, and 2-hydroxyfluorene. The analyses were performed on 3 cutoff levels (100 IU/mL, 114 IU/mL, and 150 IU/mL) set as the total IgE elevation. Prevalence of total IgE elevation by PAH exposure group and general characteristics (age, sex, BMI, smoking, alcohol drinking, and occupation) were analyzed using the Rao-Scott χ² test. Multiple logistic regression analyses were conducted to calculate adjusted odds ratios (ORs) for total IgE elevation by PAH exposure groups. Results: Total IgE elevation differed significantly by age, sex, smoking status, alcohol drinking status, and occupation. For 2-hydroxyfluorene, the fourth quartile showed a significant association with IgE elevation compared to the first quartile in the analyses of cutoff-level 100 IU/mL (OR: 1.372, 95% confidence interval [CI]: 1.007-1.869) and 114 IU/mL (OR: 1.643, 95% CI: 1.167-2.312). In the analysis of cutoff-level 150 IU/mL, the adjusted ORs of the third and fourth quartile of 2-hydroxyfluorene were significantly higher than the first quartile (3rd quartile: OR: 1.478, 95% CI: 1.034-2.113; 4th quartile: OR: 1.715, 95% CI: 1.161-2.534). However, there were no significant positive associations for the other metabolites. Conclusions: This study implied that PAHs exposure is associated with total IgE elevation in Korean adults. More research is needed to confirm the effect of exposure to PAHs on serum IgE and allergic diseases.