• Journal of Soil and Groundwater Environment
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• v.20 no.6
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• pp.1-7
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• 2015

The most critical health effect of lead exposure is the neurodevelopmental effect to children caused by the increased blood lead level. Therefore, the endpoint of the risk assessment for lead-contaminated sites should be set at the blood lead level of children. In foreign countries, the risk assessment for lead-contaminated sites is conducted by estimating the increased blood lead level of children via oral intake and/or inhalation (United States Environmental Protection Agency, USEPA), or by comparing the estimated oral dose to the threshold oral dose of lead, which is derived from the permissible blood lead level of children (Dutch National Institute for Public Health and the Environment, RIVM). For the risk assessment, USEPA employs Integrated-Exposure-Uptake-Biokinetic (IEUBK) Model to check whether the estimated portion of children whose blood lead level exceeds 10 µg/dL, threshold blood lead level determined by USEPA, is higher than 5%, while Dutch RIVM compares the estimated oral dose of lead to the threshold oral dose (2.8 µg/kg-day), which is derived from the permissible blood lead level of children. In Korea, like The Netherlands, risk assessment for lead-contaminated sites is conducted by comparing the estimated oral dose to the threshold oral dose; however, because the threshold oral dose listed in Korean risk assessment guidance is an unidentified value, it is recommended to revise the existing threshold oral dose described in Korean risk assessment guidance. And, if significant lead exposure via inhalation is suspected, it is useful to employ IEUBK Model to derive the risk posed via multimedia exposure (i.e., both oral ingestion and inhalation).

• Journal of Environmental Health Sciences
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• v.40 no.3
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• pp.178-186
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• 2014

Background: This study was conducted to assess health risks in regard to exposure by children to volatile organic compounds (VOCs) in children's products. Methods: Ten VOCs were measured by head-space gas chromatography in children's products, including toys, oil pastels, sign pens, furniture, ball pools, and playmats. We estimated the average daily dose (ADD) via inhalation during the use of these children's products and calculated hazard quotient (HQ) by dividing ADD by reference dose of VOCs. Results: Among the measured VOCs, five compounds were identified in children's products: benzene, ethylbenzene, styrene, toluene, and xylene. The detection rates of VOCs in toys, ball pools, furniture, playmats, sign pens, and oil pastels were 85%, 100%, 100%, 30%, 100%, and 60%, respectively. The maximum levels of VOCs were 0.18 mg benzene/kg in toys, 5.92 mg toluene/kg in playmats, 10.37 mg ethylbenzene/kg in ball pools, 24.85 mg xylene/kg in toys, and 118.29 mg styrene/kg in ball pools. From exposure levels of VOCs in the children's products HQs were calculated within a range of $5.71{\times}10^{-10}$ to $4.77{\times}10^{-4}$. The HQ of xylene was the highest for children aged 0-6 playing on the playmats. However, the HQ via inhalation exposure to VOCs in individual products did not exceed 1.00. Conclusion: Based on the results, it was concluded that the use of these children's products do not pose health risks to children.

• Journal of Radiation Protection and Research
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• v.26 no.2
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• pp.79-86
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• 2001

This study presents the quantitative exposure assessment of indoor radon released from groundwater. Most of the Indoor radon comes directly from soil beneath the basement or foundation. Recently, radon in groundwater releases to indoor air whenever the water is used and contributes to the total inhalation risk from indoor air. This study first develops a mathematical model to describe the transfer and distribution of radon released from groundwater in a house. Then, daily human exposures through inhalation or such radon are estimated with the model for an male adult based on two sets of exposure scenarios. The results obtained from the study would help increase the understanding of risk assessment issues associated with the indoor radon released from groundwater.

• Biomedical Science Letters
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• v.11 no.3
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• pp.267-274
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• 2005

Formaldehyde (FA) is an important industrial chemical, but it can cause allergic reactions, sick building syndrome and so on. It has also been observed to cause cancer in scientific studies using laboratory animals, and it even causes cancer in humans. Natural products such as ginseng and pine needle containing complicated mixtures of organic chemicals are widely used in the world, because their effective components are responsible for some pharmacological activities including antioxidative effect, anticancer effect. We investigate the effect of Korean ginseng (GE), pine needle extract (PE) and combined GE and PE (cNPE) on mouse lung injury by FA exposure. GE, PE and cNPE was directly transported to pulmonary cells through respiratory organ by nebulizer inhalation. In the case of FA exposure, the pulmonary structure was damaged and its function became abnormal. However, cNPE-FA, GE-FA, and PE-FA treated groups showed similar with the control group compared with FA group. Among them, GE was proved to be more effective than any other extracts. These results demonstrate that natural product extracts could protect pulmonary structure and function against FA exposure.

• Journal of Environmental Policy
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• v.7 no.1
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• pp.1-29
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• 2008

The Ministry of Environment(MoE) of Korea has recently established the Environmental Health Act. This Act contains a clause related to implementation of Health Impact Assessment(HIA). So, selecting a landfill which was expected to have an influence on human health among major development projects, this study carried out the human risk assessment due to inhalation exposure to landfill gas emission and attempted to measure the possibility of domestic application of HIA in the future. The process for HIA on landfill site extension focusing on human risk assessment is as follows: The first step is to presume and calculate the amount of landfill gas emissions using LandGEM, The second step is to carry out exposure assessment using K-SCREEN Model which is used for predicting the concentration in a conservative method. The last step is to carry out human risk assessment of carcinogenic and non-carcinogenic substances. It is considered that it is likely to apply a technique for human risk assessment due to inhalation exposure to landfill gas emission performed here more specifically in the case of implementing HIA. In addition, it is also believed that more systematic studies are needed to overcome some weak points and limits found in this study and if these weak points and limits are improved more reliable outcomes will be produced.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.14 no.2
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• pp.129-132
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• 2003

Chlorine gas is highly irritating gas that, when inhaled, can damage larger airways as well as distal lung structure. It occurs usually result in mild ocular, oropharyngeal, or respiratory symptom and recovery may proceed slow for several weeks. We reported four cases of dysphonia due to acute chlorine inhalation during a swimming pool accident were treated by voice therapy and medication.

• Journal of Preventive Medicine and Public Health
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• v.47 no.1
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• pp.7-17
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• 2014

Risk assessment considers the situations and characteristics of the exposure environment and host. Various physiological variables of the human body reflects the characteristics of the population that can directly influence risk exposure. Therefore, identification of exposure factors based on the Korean population is required for appropriate risk assessment. It is expected that a handbook about general exposure factors will be used by professionals in many fields as well as the risk assessors of the health department. The process of developing the exposure factors handbook for the Korean population will be introduced in this article, with a specific focus on the general exposure factors including life expectancy, body weight, surface area, inhalation rates, amount of water intake, and soil ingestion targeting the Korean population. The researchers used national databases including the Life Table and the 2005 Time Use Survey from the National Statistical Office. The anthropometric study of size in Korea used the resources provided by the Korean Agency for Technology and Standards. In addition, direct measurement and questionnaire surveys of representative samples were performed to calculate the inhalation rate, drinking water intake, and soil ingestion.

• Toxicological Research
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• v.13 no.3
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• pp.251-256
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• 1997

Toluene inhalation increases glutamate level and its receptor in various brain regions. In this study, nitric oxide synthase (NOS) activities were investigated in various rat brain regions using NADPH diaphorase staining method which examined histochemical changes of NOS in the neural cells. Also, in vitro LDH leakage assay and MTT test were performed to investigate the toxic influences of toluene in cultured granule cell of rat cerebellum which was significantly affected with toluene in vivo. Rats were exposed to toluene of 10000 ppm for 3 days. 7 days and 14 days by 20 min $\times$ 2 times a day. NADPH diaphorase staining was processed in the different brain regions after inhalation. NADPH diaphorase staining density was not significantly changed at 3 days inhalation group, but the density decreased in proportion to the duration of toluene inhalation. Over 30% of staining density was decreased at 14 days group which was maximum duration of inhalation in this study. The tendency of staining density decrease was significant in granule cell of cerebellum. Cell death by toluene exposure was observed in cultured cerebellar granule cell. $EC_{50}$ measured with LDH leakage assay and MTT test were 43 mM and 72 mM respectively.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.4
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• pp.327-334
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• 2002

The work presents sensitivity and uncertainty analysis of 2-compartment model for the evaluation of indoor radon pollution in a house. Effort on the development of such model is directed towards the prediction of the generation and transfer of radon in indoor air released from groundwater. The model is used to estimate a quantitative daily human exposure through inhalation of such radon based on exposure scenarios. However, prediction from the model has uncertainty propagated from uncertainties in model parameters. In order to assess how model predictions are affected by the uncertainties of model inputs, the study performs a quantitative uncertainty analysis in conjunction with the developed model. An importance analysis is performed to rank input parameters with respect to their contribution to model prediction based on the uncertainty analysis. The results obtained from this study would be used to the evaluation of human risk by inhalation associated with the indoor pollution by radon released from groundwater.

• Journal of Soil and Groundwater Environment
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• v.9 no.1
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• pp.12-27
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• 2004

The contamination pattern of indoor air was simulated when groundwater dissolving benzene was used for household activities. Indoor exposure scenario consisted of inhalation, ingestion, and dermal absorption. Physiologically based pharmacokinetic (PBPK) model was used to analyze how benzene exposed to human body was distributed in internal organs. Main exposure pathways contributing total internal dose were inhalation and ingestion while the contribution of dermal absorption was very small. Man showed higher exposure rate than woman due to his higher breath rate. For a short-term exposure, benzene concentration in venous blood of SPT, RPT and liver changed rapidly while slowly did in venous blood of adipose tissue at a low concentration. For a long-term exposure, woman accumulated about 2.1 times higher than man. Most of benzene exposed to human body was removed by exhalation and metabolism at lung and liver, respectively. For inhalation and ingestion, the benzene removals by exhalation were 69.8 and 48.4%, respectively. Relative importance of removal mechanism was different according to the inflow displacement of benzene. The results obtained from this study would help understand exposure, distribution, and removal phenomena and make plans for the reduction of the health risk associated with the contaminated groundwater by various organic compounds.