• Asian Journal of Atmospheric Environment
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• v.5 no.4
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• pp.247-262
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• 2011

This study assessed the health risks of childhood exposure to PBDEs via different possible pathways in children's facilities and indoor playgrounds. When PBDE contamination was measured, it was determined through multiple routes, including inhalation of indoor dust, dermal contact with product surfaces and children's hands, and incidental dust ingestion. Samples were collected from various children's facilities (playrooms, daycare centers, kindergartens, and indoor playgrounds) during summer (Jul-Sep, 2007) and winter (Jan-Feb, 2008). The hazard index (HI) was estimated for non-carcinogens, and PBDEs, such as TeBDE, PeBDE, HxBDE, and DeBDE, were examined. The sensitivity to the compounds did not exceed 1.0 (HI) for any of the subjects in any facility. However, current data about toxicity does not reflect effects that were fully sensitive in children, so there is uncertainty in the dose-response data. The contribution rates of PBDEs were 71.4 to 96.1% and 3.7 to 28.2% for intake and inhalation exposure, respectively, indicating that intake of floor dust and inhalation are the primary routes.

• Journal of Radiation Protection and Research
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• v.27 no.2
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• pp.121-126
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• 2002

The work presents a realistic human exposure assessment of indoor radon released from groundwater in a house. At first, a two-compartment model is developed to describe the generation and transfer of radon in indoor air from groundwater. The model is used to estimate radon concentrations profile of indoor air in a house us]ng by showering, washing clothes, and flushing toilets. Then, the study performs an uncertainty analysis of model input parameters to quantify the uncertainty in radon concentration profile. In order to estimate a daily internal dose of a specific tissue group in an adult through the inhalation of such indoor radon, 3 PBPK(Physiologically-Based Pharmaco-Kinetic) model is developed. Combining indoor radon profile and PBPK model is used to a realistic human assessment for such exposure. The results obtained from this study would be used to the evaluation of human risk by inhalation associated with the indoor radon released from groundwater.

• Journal of Environmental Health Sciences
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• v.48 no.1
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• pp.44-51
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• 2022

Background: Air pollution is increasing together with industrialization and urbanization. In order to reduce air pollution, public transportation is recommended rather than private cars, and the number of passengers using public transportation is increasing accordingly. This study observes the concentration of indoor pollutants in city buses over time. Through this means, we intend to suggest a plan to manage the indoor air quality in city buses. Objectives: The concentration of indoor pollution in public transportation was investigated from April 2021 to January 2022. Based on this, we evaluated the exposure to indoor pollutants. Methods: Six city bus lines in an industrial city were selected for the research, and indoor pollution was measured through IoT (Internet of Things)-based sensor-type measuring devices. The concentration of pollutants was measured every minute, and statistical data were constructed based on the measurement results. Results: In all the city buses studied, the average concentration of pollutants were below the guidelines. However, some measurement results showed cases of exceeding the guidelines. As a result of the analysis by time zone, there were more cases in which pollutants exceeded the standard value during rush hour compared to at other times. A risk assessment for PM₁₀ was performed by evaluating the excess mortality risk from exposure and the risk from inhalation exposure. Conclusions: All measured indoor pollutants in the city buses did not exceed the guidelines. Also, the risk assessment results were found to be within the level of safety. However, if a city bus is used for a long time, there is a possibility that there may be an impact on the human body due to inhalation exposure, so additional management is required.

• Journal of Environmental Health Sciences
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• v.32 no.1 s.88
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• pp.19-26
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• 2006

This study was undertaken to determine the concentrations of 15 aldehydes in air samples collected from 21 households including 9 atopy patient's homes and to assess the extent of exposure and risk for an individual due to inhalation. Of all the aldehydes identified in both indoor and outdoor environment, formaldehyde and acetaldehyde were the most abundant aldehydes, which were occupied $60\%\;and\;17\%$ of total amount, respectively. The geometric mean concentration of formaldehyde and acetaldehyde in indoor air were $170.5\pm1.9\;{\mu}g/m^3\;and\;47.3\pm1.5\;{\mu}g/m^3$, respectively. There existed a strong correlation between formaldehyde, acetaldehyde and other aldehydes. And the ratio of indoor and outdoor concentrations (I/O) exceeded 1.0 for almost every measured aldehydes except m-tolualdehyde... No associations were found between the level of aldehydes and either housing characteristics or living habits in most of the samples with only a few exception. And the concentrations of all aldehydes indoor air between atopy patient's homes and control homes were not significant(p>0.05). Formaldehyde and acetaldehyde exposures and risks were estimated by using the inhalation unit risk, mean concentrations and the 95th percentiles, and which were $2.6\times10^{-3}\;and\;1.1\times10^{-4}$, respectively. The mean and the 95th percentile risk estimates were 25 times higher for formaldehyde than for acetaldehyde in homes.

• Journal of Environmental Science International
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• v.1 no.1
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• pp.47-51
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• 1992

Volatile organic rompounds(VOCs) present in the VOCs-contaminated water are released to air while showering and their air concentrations depend on the shower parameters, resulting in the variation of the VOCs breath concentration. The present study evaluated the key shower parameters(water temperature and inhalation duration) that affect the inhalation exposure to air chloroform while showering, by determining chloroform breath concentration. The chloroform breath concentrations increased with water temperature and inhalation duration increase. The two inhalation exposure conditions which resulted in the greatest chloroform breath contentration difference were a 5 min-inhalation exposure with warm water and a 15 min-inhalation exposure with hot water. The chloroform breath concentration was almost three times higher after later exposure. The mathematical model analyzing the relationship between two key shower parameters and breath concentration normalized to water concentration fits quite Ivell with the experimental data at a probability of p : 0.0001.

• Journal of Soil and Groundwater Environment
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• v.16 no.2
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• pp.12-29
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• 2011

Risk-based screening levels (RBSLs) of some pollutants for residential adults were derived with risk assessment tools developed by United States Environmental Protection Agency (USEPA), American Society for Testing and Materials (ASTM), and Korea Ministry of Environment (KMOE) and compared each other. To make the comparison simple, ingestion of soil, dermal contact with soil, outdoor inhalation of vapors, indoor inhalation of vapors, and inhalation of soil particulates were chosen as exposure pathways. The results showed that the derived RBSLs varied for every exposure pathway. For direct exposure pathways (i.e., ingestion of soil and dermal contact with soil), the derived RBSLs varied mainly due to the different default values for exposure factors and toxicity data. When identical default values for the parameters were used, the same RBSLs could be derived regardless of the assessment tools used. For inhalation of vapors and inhalation of soil particulates, however, different analysis methods for cross-media transfer rates were used and different assumptions were established for each tool, identical RBSLs could not be obtained even if the same default values for exposure factors were used. Especially for inhalation of soil particulates pathway, screening level derived using KMOE approach (most conservative) was approximately 5000~10000 times lower than the screening level derived using ASTM approach (least conservative). Our results suggest that, when deriving RBSL using a specific tool, it is a prerequisite to technically review the analysis methods for cross-media transfer rates as well as to understand how the assessment tool derives the default values for exposure factors.

• Journal of Radiation Protection and Research
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• v.16 no.1
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• pp.1-13
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• 1991

Effective dose equivalents resulting from inhalation of indoor radon-222 daughters at 12 residential areas in Korea were assessed by a simple mathematical lung dosimetry model based on the measurements of long-term averaged radon concentrations at 340 dwellings. The long-term averaged indoor radon-222 concentrations and corresponding eqilibrium equivalent radon $concentration(EEC_{Rn})$ measured by passive time-integrating CR-39 radon cups are in the range of $33.82{\sim}61.42Bq/m^3(median\;:\;48.90Bq/m^3)$ and of $13.53{\sim}24.57Bq/m^3(median\;:\;19.55Bq/m^3)$, respectively. The effective dose equvalent conversion factor for the exposure to unit $EEC_{Rn}$ derived in this study was estimated $1.07{\times}10^{-5}mSv/Bq\;h\;m^{-3}$ for a reference adult and agreed well with those recommended by the ICRP and UNSCEAR. The annual average dose equivalent to the lung $(H_{LUNG})$ from inhalation exposure to measured $EEC_{Rn}$ was estimated to be 20.90 mSv and resulting effective dose $equivalent(H_E)$ was to be 1.25 mSv, which is about 50% of the natural radiation exposure of 2.40 mSv/y to the public reported by the UNSCEAR.

• Journal of Environmental Health Sciences
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• v.44 no.4
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• pp.397-407
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• 2018

Objectives: The purpose of this study is to investigate human health risk assessment of indoor air pollutants at small-sized public-use facilities (e.g., daycare centers, hospital and elderly care facilities) that the susceptible population is mainly used. Methods: To assess indoor air quality (IAQ), the concentrations of indoor air contaminants such as HCHO, benzene, toluene, ethylbenzene, xylene, styrene, PM-10, CO, $NO_2$ and $O_3$ in air samples were measured according to the Indoor Air Quality Standard Method. By conducting the questionnaire survey, the major factors influencing IAQ were identified. Human health risk assessment was carried out in the consideration of type of use (user and worker) at 75 daycare centers, 34 hospitals and 40 elderly care facilities. Results: As a result of measurement of indoor air contaminants, the average concentration of HCHO and TVOCs in hospitals was higher than daycare centers and elderly care facilities, about 8.8 and 23.5% of hospitals were exceeded by IAQ standard. In human health risk assessment, for the user of daycare centers and elderly care facilities, the mean carcinogenic risk of HCHO inhalation was higher than acceptable value. Except for HCHO, other values were determined under acceptable risk. Similarly, for the worker of hospitals, the mean carcinogenic risk of HCHO inhalation was higher than acceptable value and other values were evaluated under acceptable risk. In contrast, the risk levels of other contaminants measured in elderly care facilities were acceptable. In the determination of factors influencing IAQ, the construction year, building type, ventilation time, and the use of air cleaner were identified. Conclusions: This study provides the information for establishing the plans of public health management of IAQ at small-sized public-use facilities that have not yet been placed under the regulation. The findings suggest the consideration of human health risk assessment results for the IAQ standards.

• Journal of Environmental Health Sciences
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• v.46 no.2
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• pp.150-158
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• 2020

Objective: This study is designed to measure the concentration of DBPs (disinfection by-products) in pool water and in air and to estimate the carcinogenic potential through the evaluation of inhalation exposure. Methods: The subjects were six indoor swimming pools with many users in Gwangju. Samples of pool water and indoor air were taken every one month from August 2018 to August 2019 and analyzed for eight swimming pool standards. Three-liter air samples were collected and the VOCs were analyzed using GC/MS directly connected to thermal desorption. Results: pH was 6.8-7.5 and the concentration of free residual chlorine in pool water was 0.40-0.96 ?/ℓ. Physicochemical test items such as KMnO₄ consumption and heavy metal items such as Aluminum met existing pool hygiene standards. No VOC materials were detected except for the DBPs. The concentration of THMs in the pool water was 11.05-41.77 ㎍/L and the THMs mainly consist of Chloroform (63-97%) and BDCM (3-31%). The concentration of indoor air THMs is 13.24-32.48 ㎍/㎥ and consists of Chloroform. The results of carcinogenic assessment of chloroform in the indoor swimming pool via inhalation exposure were 2.0 to 6.4 times higher than the 'acceptable risk level' suggested by the US EPA. Conclusions: The concentration of THMs in the pool water is 11.05-41.77 ㎍/L, most of which is chloroform. In addition, the concentration of indoor air THMs is 13.24-32.48 ㎍/㎥. The result of carcinogenic assessment of chloroform was 2.0 to 6.4 times higher than the 'acceptable risk level' suggested by the US EPA.

• Journal of Radiation Protection and Research
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• v.20 no.1
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• pp.16-24
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• 1995

Assesment of dose equivalent given by inhaled $^{222}Rn$ and its progeny has been carried out based on the concentrations of $^{222}Rn$ and its daughters in indoor air, and equilibrium factor between them measured by charcoal canister method and alpha spectrometry. Assuming the occupancy factor to be 0.8, and breathing rate to be $0.75m^3\;h^{-1}$ for public and $1.2m^3\;h^{-1}$ for occupational exposure, respectively, the regional lung dose 대valent and the resulting annual effective dose equivalent due to the inhalation of $^{222}Rn$ and its daughters in indoor air were evaluated by use of three different lung models, namely, Jacobi-Eisfeld, James-Birchall and ICRP model.