Yoon-Shin Kim

Indoor air quality in homes, offices and restaurants in Korean urban areas—indoor/outdoor relationships

Air quality monitoring was carried out to collect data on the levels of various indoor and ambient air constituents in two cities in Korea (Seoul and Taegu). Sampling was conducted simultaneously indoors and outdoors at six residences, six offices and six restaurants in each city during summer 1994 and winter 1994–1995. Measured pollutants were respirable suspended particulate matter (RSP), carbon monoxide (CO), carbon dioxide (CO2), nitrogen dioxide (NO2), and a range of volatile organic compounds (VOCs). In addition, in order to evaluate the effect of smoking on indoor air quality, analyses of parameters associated with environmental tobacco smoke (ETS) were undertaken, which are nicotine, ultraviolet (UVPM), fluorescence (FPM) and solanesol particulate matter (SolPM). The results of this study have confirmed the importance of ambient air in determining the quality of air indoors in two major Korean cities. The majority of VOCs measured in both indoor and outdoor environments were derived from outdoor sources, probably motor vehicles. Benzene and other VOC concentrations were much higher during the winter months than the summer months and were not significantly greater in the smoking sites examined. Heating and cooking practices, coupled with generally inadequate ventilation, also were shown to influence indoor air quality. In smoking sites, ETS appears to be a minor contributor to VOC levels as no statistically significant relationships were identified with ETS components and VOCs, whereas very strong correlations were found between indoor and outdoor levels of vehicle-related pollutants. The average contribution of ETS to total RSP concentrations was estimated to range from 10 to 20%.

Odor reduction rate in the confinement pig building by spraying various additives.

The objective of this on-site experiment was to evaluate and compare the effectiveness of currently utilized various additives, i.e. tap water, salt water, digested manure, microbial additive, soybean oil, artificial spice and essential oil, to reduce odor emissions from the confinement pig building. Odor reduction rates were evaluated with respect to sensual odor (odor concentration index, odor intensity and odor offensiveness) and odorous compounds (ammonia and sulfuric odorous compounds). Of the additives investigated in this study, salt water, artificial spice and essential oil had a positive effect on reducing odor generation. The effectiveness of salt water was only observed on ammonia, showing the reduction rates as a function of time (t=immediately, 1h, 3h, 5h, and 24h after spraying) were 0.1%, 20%, 36%, 11% and 0.2% as compared to initial level before spraying. The odor intensity and offensiveness were lessened by spraying artificial spice and essential oil of which maximum reduction rates ranged from 60% to 80%. Additionally, the essential oil had a significant effect on reducing sulfuric odorous compounds for 24h after spraying, which implicates that it functioned as not only a masking agent but also as an antimicrobial agent.

Factors influencing indoor air quality in Hong Kong: Measurements in offices and shops

Abstract Comparisons of levels of respirable suspended particulates, carbon monoxide, carbon dioxide, nitrogen dioxide, volatile organic compounds and nicotine have been made between indoor and outdoor air in 35 street‐level shops and 35 offices in Hong Kong. Additionally, counts of bacteria and fungi were made indoors. In shops, the study showed that the air quality was principally determined by outdoor air, with highly significant correlations between indoor and outdoor levels of RSP, CO and NO2. The levels of these substances were significantly lower in offices. Measurement of analytes related to tobacco smoking showed extremely low levels of environmental tobacco smoke in both shops and offices, but the overall numbers of smokers in such establishments was small. For offices, occupier complaints regarding drowsiness, headache and symptoms of eye, nose and respiratory tract irritation were positively associated with CO2 levels. NO2, CO, toluene and benzene levels did not show any relationship to occupi...

The Relationship between Rehabilitation and Changes in Depression in Stroke Patients.

[Purpose] This study investigated the primary factors behind changes in depressive symptoms among stroke patients after 8 weeks of rehabilitation (physical, occupational, and cognitive therapy). [Methods] This study was conducted using a literature review, and electronic medical records from January, 2008 to December, 2009. Data were collected for 120 subjects with chronic stroke. [Results] Cardiac disorder, left-brain lesion, early-stage depression, activities of daily living, and cognitive function were significant predictors of the changes in depression in chronic stroke patients. [Conclusion] Post-stroke depression can be controlled by rehabilitation. Also, clinicians should comprehend and share the psychological and physical affliction, develop back-up programs, and make them comprehensively available to support the psychological and physical health of subjects with chronic stroke.

Continuous Observation of Atmospheric 222Rn Concentrations for Analytic Basis of Atmospheric Transport in East Asia

The observation network of atmospheric radon-222 (222Rn) concentration established in East Asia region is introduced, and the characteristics of the observations at two continental sites Beijing and Seoul and three remote sites Cape Ochiishi, Hachijo Is. and Hateruma Is. are discussed in this paper. Higher levels of 222Rn concentrations with typical diurnal variation with early morning maxima were observed on the continent, and lower levels with no diurnal variation at remote islands. Seasonal variations with summer minima and winter maxima were commonly obtained at all five observatories, and they suggested contribution of 222Rn originated from the continent to atmospheric 222Rn over the remote islands isolated in the ocean. A backward trajectory analysis showed clear relationship between variation in wind field and in 222Rn concentration at Hachijo Is., and proved availability of the observation for analysis of atmospheric transport in East Asia.

Monte Carlo simulations on performance of double-scattering Compton camera

A double-scattering Compton camera that can effectively obtain three-dimensional emission images in high-energy gamma-ray applications such as nuclear decommissioning and particle therapy monitoring has been developed. The double-scattering Compton camera utilizes two position-sensitive detectors as scatter detectors to determine the trajectory of a scattered gamma-ray, and a scintillation detector as absorber detector to measure the remaining energy of the double-scattered gamma-ray. The benefit of using two scatter detectors is the accurate determination of the gamma-ray trajectory after the scattering at the first scatter detector, which makes possible higher imaging resolution. In the present study, Geant4 Monte Carlo simulations were conducted to compare the performance of the double-scattering Compton camera with that of a similarly dimensioned single-scattering Compton camera for different source energies. Further, the optimal geometry of the multiple-detector-type double-scattering Compton camera was investigated for the purposes of increasing its imaging sensitivity. The results showed that the double-scattering Compton camera offers superior angular resolution over the entire energy range considered in the present study, whereas the single-scattering Compton camera provides greater sensitivity. The results also showed that, in general, the placement of additional detectors in the axial direction (i.e., stacking) is more effective for sensitivity improvement than doing so in the planar direction. This axial placement, however, lowers the imaging resolution. The double-scattering Compton camera exhibited the highest sensitivity when the additional scatter detectors were added to the first scatter detector in the axial direction, and exhibited the highest imaging resolution when the additional detectors were added to first scatter detector in the planar direction. Therefore, the results generally indicated that the first scatter detector is more important than the second not only for improving the sensitivity but also for maintaining a high imaging resolution. We believe that the present studys findings will provide valuable guidelines to researchers looking for the best Compton camera designs for certain objectives.

Cultural heritage: a potential pollution source in museum

IntroductionThe purposes of this study, as part of research projects for establishing the preservation environment of domestic cultural properties, are to identify the hazardous environmental factors which have a possibility to cause damages on long-term preservation of cultural heritage within the museum exhibition halls and the storages area, and to provide the basic data for the future establishment of preservation environment.Materials and methodsThe temperature (23.5 and 20.6°C,) relative humidity (52.1% and 55.4%), PM10 (31.5 and 18.9 μg/m3), CO2 (472.7 and 526.8 ppm), HCHO (20.8 and 34.0 μg/m3), CO (0.3 and 0.3 ppm), NO2 (0.012 and 0.004 ppm), TVOCs (493.6 and 788.9 μg/m3), O3 (0.003 and 0.002 ppm), Rn (0.7 and 1.5 pCi/L), and SO2 (0.003 and 0.002 ppm) as chemical factors, and airborne bacteria and fungi as biological factors, were selected for this research subjects of hazardous environmental factors, which were the subjects of the study conducted by the National Research Institute of Cultural Heritage from 2006 to 2008, and the subjects of related domestic researches performed in fragments.Results and discussionThe concentration distributions of selected hazardous environmental factors in a museum environment were calculated by using the inverse variance weighted average in meta-analysis, and the concentration distributions possibly emerging in a museum exhibition halls and storages were computed through Monte Carlo simulation in order to minimize the uncertainty that can be caused from meagerness of related domestic researches.

A Survey for Some Asbestos Containing Products in Korea

This study was performed to investigate the current status, in Korea, of the production of asbestos containing products (ACPs) such as asbestos cement products, asbestos friction materials, asbestos joint sheets, asbestos textile products, and other asbestos-containing products from May 2 to July 30, 2007. The information on ACPs was obtained through written questionnaires from 16 of the 27 companies that produce ACPs in Korea. The production amounts of asbestos containing gaskets were 70 tons in 2004, 90 tons in 2005, and 55 tons in 2006 in 4 companies and that of asbestos friction materials were 435.5 tons in 2004, 540.4 tons in 2005, and 454.3s ton in 2006 in 10 companies. The type and number of ACPs were:- 19 asbestos cement products, produced by 2 companies; 47 asbestos friction materials produced by 18 companies; 12 asbestos joint sheets productes by 4 companies; 18 asbestos textile products from 3 companies, and 6 other asbestos products from 5 companies. The database of ACPs was constructed to include the products name, identification number, name of company, production year, composition, asbestos content (%), usage, specification, and a picture. The database will be used to efficiently identify ACPs and to avoid asbestos exposure in workers and the general population.

A Proposal of Hazard/Risk Assessment Criteria and an Asbestos Management Method for Asbestos-containing Building Materials

Objectives: The AHERA method by the US EPA, ASTM E2356-04, and HSG264 by the UK HSE, all of which are hazard/risk assessment methods for asbestos-containing building materials, were reviewed and compared based on 231 homogeneous areas. In addition, the current Act on Asbestos Safety Management (enforcement: April 29, 2012) was reviewed and analyzed. This trial provided fundamental data for improving the current asbestos hazard/risk assessment method. Methods: For the hazard/risk assessment of 77 asbestos-containing public buildings including schools, 231 homogeneous areas were selected, each of which was assessed using AHERA, ASTM E2356-04, and HSG264. Results: The matching rate of the hazard/risk assessment stood at 20.4 percent between AHERA and ASTM, at 71.4 percent between AHERA and HSG264 and at 17.8 percent between ASTM and HSG264. The AHERA method includes a seven-category rating scale. There were three categories, two of which have three subcategories. ASTM provides two decision-making charts consisting of ten rating scales for current condition estimation and for potential for disturbance estimation. In addition, the HSG264 method has a total of 20 scores with four items, and then provides four grades. This HSG264 method cannot clearly separate current condition and potential for disturbance. Conclusions: In the Korean Act on Asbestos Safety Management, the hazard/risk assessment method for asbestos-containing building materials should consider balance between current condition estimation and the potential for disturbance estimation.

Field Study on the Impact of Indoor Air Quality on Broiler Production

The presented research investigated the impact of indoor air quality on the production of broilers. Three broiler houses of different air quality environments with different controlled ventilation rates and uses of super plasma ionizing (SPI) air purifiers were investigated. The broilers were fed with antibiotic or non-antibiotic feeds to determine if the air quality control could be sufficient to keep broilers healthy without using antibiotics. The weight gain, mortality rate and serum cholesterol level of broilers were monitored as the benefit indicators of air quality and antibiotics. The results showed a higher weight gain of the broilers in the broiler house with a higher ventilation rate. SPI air purifier could benefit the weight gains of the broilers, but was not always significant. The uses of higher ventilation rate, SPI air purifier and antibiotics could reduce the mortality rate of broilers. The impact of air quality on reducing the serum cholesterol level of broilers was not found in this research. The inference of this research was that ventilation could be an effective way to increase the broiler productivity, while an optimum setting of ventilation rate is essential to ensure the broilers and keepers are safe from any harmful effects. In the case that the ambient environment had been severely polluted, air purifiers would be indispensable to complement ventilation to reduce certain target pollutants.