• 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.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.1
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• pp.1-10
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• 2008

Purpose: This study was aimed to examine the resorption rate, the healing pattern, and the response of the surrounding tissue after the graft of the acellular dermal matrix ($AlloDerm^{(R)}$) and the autogenous dermis, and to report the clinical result of the use of $AlloDerm^{(R)}$ in order to restore the soft tissue defects. Methods: Twenty mature rabbits, weighing about 3 ㎏, were used for the experimental study. The $10\times10$ mm-size autogenous dermis and the $AlloDerm^{(R)}$ were grafted to the space between the external abdominal oblique muscle and the fascia of the rabbits. And the $AlloDerm^{(R)}$ was grafted to the pocket between the skin and the underlying perichondrium of rabbit ear. The resorption rate of the grafted sites was calculated, and the tissue specimens were histologically examined at 1, 2, 4, and 8 weeks after the graft. The five patients with the cleft-lip nasal deformity and the one patient with the saddle nose deformity, who received the $AlloDerm^{(R)}$ graft to restore the facial soft tissue defects, were reviewed for the clinical study. Results: The resorption rate at 8 weeks after the graft was 21.5% for the autogenous dermis, and 16.0% $AlloDerm^{(R)}$. In microscopic examinations, the infiltration of the inflammatory cells and the epidermal inclusion cyst were observed in the autogenous dermis graft. However, the neovascularization and the progressive growth of the new fibroblasts were shown in the $AlloDerm^{(R)}$ graft. And the six patients, who received the $AlloDerm^{(R)}$ graft, demonstrated the good stability of the grafts and improved appearance. There were no remarkable complications such as inflammation, rejection, dislocation, and severe absorption in the clinical cases. Conclusion: These results suggest that $AlloDerm^{(R)}$ can be an useful graft material for restoration of soft tissue defects because of the good stability and the tissue response without the remarkable clinical complications.

• Analytical Science and Technology
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• v.25 no.6
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• pp.416-420
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• 2012

The increasing use of recycling products results in the need for assessing the risk to human health. In this study heavy metals's contents of playground flooring were compared with rubber powder which is row material. And it is reviewed characteristics of heavy metals's exposure from absorption of skin, checking amount of dermal uptake for each heavy metal. Despite its high content, Zn had a very low migration rate with 0.1 $mg/cm^2$. This indicates that Zn is not easily released by surface contact. However, the contents of Fe and Al in flooring were 12 times higher than that of Zn and Fe, and Al showed migration rate 5 times higher than that of Zn. This implies that Fe and Al were derived from pigment in flooring. The measurement of dermal exposure to heavy metals at 6 playgrounds found higher level of exposure in Ba than in other heavy metals. It is assumed that despite high content of Zn, Ba had a higher exposure rate because five times as much Ba as Zn was darmal absorptionactor ($AF_{darmal}$).

• Journal of Soil and Groundwater Environment
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• v.12 no.1
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• pp.64-72
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• 2007

Humans are exposed by a range of pollutants in soil via exposure routes such as ingestion, inhalation, and dermal contact. Risk assessment is a process of evaluating the adverse health effects of chemicals as a result of exposure to stressors, and it is a very useful tool to establish the cleanup goals in contaminated lands. In the exposure assessment that is one of main process in risk assessment, exposure factor plays a significant role to quantify the intake of soil pollutants. However there is a very limited study about the exposure factor applicable to Korea. In this study, we compared the exposure factors applied by the developed countries including the United States and representative European countries, and suggested the exposure factor that might be suitable in our situation. The exposure factors considered in this study include average lifetime, body weight, (exposed) skin surface area, life time, skin absorption, soil-skin adherence factor, and soil ingestion rate. This information is needed to quantitatively estimate the intake of soil pollutants in contaminated lands.

• Environmental Analysis Health and Toxicology
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• v.11 no.1_2
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• pp.19-29
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• 1996

Human exposure to volatile compounds in tap water can occur from inhalation and dermal absorption as well as direct ingestion. The relative contribution to total human exposure from these pathways has been considered to be important especially for VOC's (volatile organic compounds). In an attempt to reduce the uncertainty of the risk assessment, it has been suggested that the exposure assessment process could be significantly improved by adopting Monte-Carlo simulation. However, there is no actual data in Korea for each exposure parameter to determine the level of exposure, and the distributional pattern. Therefore, we surveyed water use patterns and behavior related to multi-route exposure to VOC's in household tap water in Korea, and compared these values to the those in western countries. In the first survey, we calculated daily water intake using data from a sample of 1322 persons of several cities in Korea. In the second survey, we obtained questionnaire data on exposure time for showering, bathing and household activities, and tap water intake from 851households in Korea. In the last survey, we measured the exposure parameters (exposure time, water use rate etc.) related to showers, baths, toilets, dish washing, washing and cooking, and tap water intake was surveyed. Also, the subjects were measured their body weight, height and tidal volume, etc. A diary, a flow meter and a measuring cup were used to measure these values as precisely as possible. Average daily water intake was ranged 0.79-1.71 L/day for adults in three surveys. Tap water intake measured by log-sheet during one week in third survey was 1.26 (average), 1.98 L/day (90 percentlie), respectively. These results were comparable with results from EPA (1.4, 2L/day). The average amount of water used by housewives in the third survey was 515.0 $\pm$ 564.6L/day. In usual activity, the amount of water used in the bathroom, the laundry and the kitchen was 140.0 $\pm$ 538.9, 148.0 $\pm$ 174.5, 229.3 $\pm$ 205.4 L/day, respectively. Exposure parameters such as water intake rate, exposure duration, body weight, inhalation rates in surveyed data of Korean people differed from those published from western countries. This could be attributed to variations in lifestyle, dietary habits and physiological characteristics.

• Journal of Environmental Health Sciences
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• v.49 no.6
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• pp.324-333
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• 2023

Background: Human exposure to phthalates in indoor environments occurs via dermal absorption, oral ingestion of indoor dust, and inhalation of indoor air. However, systematic studies to investigate the exposure rate to phthalates among the three exposure routes in indoor environments are currently limited. Objectives: A theoretical exposure ratio between inhalation and oral exposure was calculated based on the total amount of di(2-ethyl-hexyl) phthalate (DEHP) emitted into indoor air and deposited into floor dust in a test house. Methods: Flooring and wallpaper containing DEHP were installed in a test house and the concentration of DEHP in both indoor air and floor dust were monitored for five months. Based on the measured DEHP concentrations, the theoretical total amount ratio of DEHP that could be exposed through inhalation and oral ingestion was calculated. Results: Considering the period of operation in the test house, the theoretical total amount of DEHP through inhalation and oral ingestion exposures in the entire test house space was calculated to be 0.014 mg and 5.5 mg, respectively. The exposure ratio of the two routes between inhalation and oral exposure corresponding to the total DEHP amount in flooring and wallpaper was 6.0×10^-7% and 2.3×10^-4%, indicating that theoretical oral exposure to DEHP is approximately 380 times higher than inhalation. Conclusions: Monitoring results from a test house has shown that oral exposure is the main exposure route for DEHP in indoor environments. The experimental design employed in this study and theoretical exposure ratio obtained can be applied to investigate actual exposure to DEHP and to determine the exposure characteristics of various types of semi-volatile organic compounds.