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Since most people spend more than about 90% of the day in indoor environments, indoor air quality is a major setting for assessing exposure to air pollutants. Factors affecting indoor air quality a... more...

Humans have a desire to inhale the fresh outdoor air even indoor air quality is satisfactory. When the window is opened to ventilate, air quality satisfaction maybe higher than closed even the not ... more...

Background/AimExposures among children are expected to be different from exposures among adults, because of physiological and behavioural differences. Children may be more exposed to some environme... more...

Most hospitals have air-conditioning facilities, but many people are moving, and there are many indoor air pollutants such as fine particle. In this study, air purifier is installed in hospital war... more...

Mold stain remover (MSR) is used to clean mold and mildew spots from surfaces and contains a variety of chemical substances. In this study, we estimated the inhalation and dermal exposures associated with the use of trigger spray MSRs, and performed screening-level risk assessments for the use of this type of product in Korea. Inhalation and dermal exposures were estimated using exposure algorithms based on exposure factors obtained from a nationwide survey of 10,000 participants and chemical analyses of the four most popular trigger spray MSRs. The hazard quotients (HQs) for noncancer risk and excess cancer risk (ECR) were calculated for each chemical. The mean inhalation exposure estimates for formaldehyde, benzene, chloroform, and carbon tetrachloride were 6.9 × 10−7, 1.7 × 10−7, 5.4 × 10−6, and 2.7 × 10−5 mg/kg/day, respectively. Dermal exposures of the chemicals were 5.7–6.5 times higher than inhalation exposures. The HQs for total exposure were all below 1, which indicated little noncancer risk from the use of MSRs. The safe ECR value of 1 × 10−6, was exceed in one subject for inhalation exposure of benzene and four subjects for dermal exposure of formaldehyde, while 19.8% for dermal exposure of benzene were above this value. Therefore, use of trigger spray MSRs in Korea should require more detailed exposure and risk assessment, especially for benzene. more...

Objectives: Exposure to volatile organic compounds such as trichloroethylene(TCE) and perchloroethylene(PCE), along with Agent Orange, that were issued around Camp Carroll US Army Base situated in Waegwan, Chilgok-gun, Gyeongsangbuk-do Province, Korea. The main objective of this study was to assess the exposure to TCE and PCE of residents of the area surrounding Camp Carroll. Methods: The TCE, PCE and trichloroethanol(TCEOH) concentrations in blood and trichlroroacetic acid(TCA) and TCEOH concentrations in urine were measured and analyzed in a total of 1,033 residents around Camp Carroll. TCA and TCEOH are metabolites of TCE and PCE, respectively. The information on demographic characteristics and exposure variables in relation to underground water were obtained through a questionnaire completed by the subjects. Results: TCE, PCE and TCEOH concentrations were not detected in blood. Detection rates of TCA and TECOH concentrations in urine were 98.5% and 36.6%, respectively. Creatinine-corrected average TCA and TCEOH concentrations were 12.23±23.81 μg/g and 0.66±4.31 μg/g, respectively. A significant difference was not shown between the drinking group and no drinking group for underground water, which was assumed as a potential route of exposure to TCE and PCE through the consumption of ground water. However, females drinking ground water showed a significantly higher mean level of TCA in urine than did males. There was no significant difference according to drinking ground water as a potential source of exposure to TCE and PCE in residents around Camp Carroll. Conclusions: Considering the statistical analysis of factors affecting exposure to TCE and PCE in ground water along with previous reports, TCA in urine as exposure to TCE and PCE might not be appropriate because it is found in chlorinated drinking water. Therefore, TCA concentration in urine may be the result of drinking of chlorinated water. more...

Purpose In some countries with high smoking prevalence, smoke-free legislation has only been implemented in specific public places, as opposed to a comprehensive ban on smoking in all public places. The purpose of this study was to provide valid data on second-hand smoke (SHS) exposure that reflect the consequences of incomplete smoke-free legislation, and provide a rationale for expanding this legislation. Materials and methods Indoor and outdoor environmental exposure (fine particulate matter [PM2.5], air nicotine, and dust 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone [NNK]) was monitored in 35 public places where smoking is prohibited by law in Goyang, Republic of Korea. Biomarkers of SHS exposure (urinary cotinine, hair nicotine, and urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol) were measured in 37 non-smoking employees. Geometric means and standard deviations were used in comparison of each measure. Results Considerable exposure of SHS was detected at all indoor monitoring sites (PM2.5, 95.5 μg/m(3) in private educational institutions; air nicotine, 0.77 μg/m(3) in large buildings; and dust NNK, 160.3 pg/mg in large buildings); environmental measures were higher in private or closed locations, such as restrooms. Outdoor measures of SHS exposure were lowest in nurseries and highest in government buildings. Biochemical measures revealed a pattern of SHS exposure by monitoring site, and were highest in private educational institutions. Conclusion The evidence of SHS exposure in legislative smoke-free places in Korea suggests that incomplete smoke free legislation and lack of enforcement of it might not protect people from exposure to smoke. Therefore, active steps should be taken toward a comprehensive ban on smoking in all public places and its enforcement. more...

[Purpose] The purpose of the present study was to determine whether there was a correlation between basic physical fitness and pulmonary function in Korean school students, to present an alternative method for improving their pulmonary function. [Subjects and Methods] Two hundred forty healthy students aged 6–17 years performed physical fitness tests of hand-grip strength, sit and reach, Sargent jump, single leg stance, and pulmonary function tests of forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) using a Quark PFT. [Results] Muscle strength and power of boys improved in the late period of elementary school and middle school. Muscle strength of girls improved in the late period of elementary school. Analysis of factors affecting pulmonary function revealed that height, weight, BMI, and body fat significantly correlated with spirometric parameters. Right hand-grip strength, left hand-grip strength, and Sargent jump also significantly correlated with FVC and FEV1. [Conclusion] In order to improve the pulmonary function of children and adolescents, aerobic exercise and an exercise program to increase muscle strength and power is needed, and it should start in the late period of elementary school when muscle strength and power are rapidly increasing. more...

Objective: In May 2011, an interview with three United States Forces Korea veterans revealed that chemicals believed to be 'Agent Orange' were buried at Camp Carroll (situated in Waegwan, Chilgok-gun, Gyeongsangbuk-do, Korea) in 1978. Many hazardous chemicals, such as perchloroethylene (PCE), trichloroethylene (TCE), and organochlorines were subsequently found in a joint US-ROK environmental investigation, although dioxins or burial evidence related to 'Agent Orange' have been not uncovered. This study was carried out to investigate the relevance of hazardous chemical exposure and health effects of the residents around Camp Carroll. Methods: The authors conducted a health questionnaire survey among residents around Camp Carroll regarding Waegwan groundwater ingestion, length of residence in Waegwan, and physician-diagnosed disease history (such as cancer, hypertension, diabetes and etc.). Logistic regression was performed to identify the associations between hazardous chemical exposure and physician-diagnosed diseases. Results: Among the 5,320 residents, excluding those living outside the Waegwan area, 3,430 subjects age 30 and over were analyzed. Among females, upon correction of age, smoking history and Camp Carroll working history, a higher distribution in the Waegwan groundwater ingestion group was demonstrated for patients with physician-diagnosed cancer and hypertension. The odds ratios have a tendency to increase with increased length of Waegwan groundwater ingestion. Conclusions: This study may be limited by not adopting a cohort study for the evaluation of factors that may confound environmental exposure. Yet it is meaningful that the correlation between Waegwan groundwater ingestion and chronic diseases were found through regression analysis in female; and further, this outcome may be used as a sampling basis for a secondary epidemiologic study. more...

Objectives: As the suspicion was raised that ‘Agent Orange’ was reclaimed 30 years ago at Camp Carol, located in Waegwan, Gyeongsangbuk-do, the government conducted an investigation of the influence of environmental and health effects around Camp Carol through a public-private joint investigation team. As part of the investigation of population health effects, this study was carried out in order to observe changes and regional differences in diseases, particularly cancer, by year. Methods: We authors conducted an analysis of secondary health data, such as cancer registration data, mortality data, and health insurance data. We drew an age standardized incidence ratio (SIR), death rate (SDR), mortality ratio (SMR), and health care utilization rate using these data. Results: For gastric cancer in women, and other cancers in men, a significant increase in incidence was observed compared to the control area. For biliary tract cancer, gallbladder cancer, and thyroid cancer in women, and prostate cancer in men, a significant decrease in incidence was observed compared to the control area. In the national statistical analysis of data, such as health insurance data and mortality data, we did not observe a significant increase at the Waegwan region compared to other regions. Conclusions: We must consider the limitations of this study. Because thirty years have passed from the time of the estimated landfill of ‘Agent Orange’, recent national statistical data may not reflect the past real situation. Therefore, the monitoring of secondary data for health effects at the municipal level should be carried out continuously. more...

Objectives: This study describes the results of a mass screening and secondary questionnaire conducted among sampled residents around Camp Carroll. Methods: The subjects were sampled based on Waegwan groundwater ingestion history via a primary health questionnaire survey. However, the study population included voluntary participants and there were no grounds for disqualification. Among the 1,033 residents, excluding people living outside Waegwan, 844 subjects age 30 and over were analyzed. History of physician-diagnosed disease (including detailed history of cancer), eating habits, drinking and smoking histories were queried through questionnaires. Health screening consisted of a blood pressure check and blood test (complete blood cell, liver enzyme, lipid, blood sugar test, etc.). Results: The proportion of abnormal gamma-glutamyltransferase levels was higher in the groundwater ingesting female group than the non-ingesting female group. The odds ratios of the ingested '1 to 9 years' and '10 years and over' groups were 3.09 and 0.87, respectively. Proportions of hypertension in males, abnormal serum triglyceride levels in all and in females, and abnormal serum high density lipoprotein cholesterol levels in males were higher in the '10 to 29-year' resident group than in the '1 to 9 year' group. However, there were no significant trends according to length of residence. Conclusions: Physician-diagnosed prevalence and laboratory test results are not different by histories of Waegwan groundwater ingestion and by length of residence. Even if there are partially significant differences, they do not tend to follow increases of exposure amount and trends. more...

Metal contamination from mining activity is of great concern because of potential health risks to the local inhabitants. In the present study, we investigated the levels of Cd, Cu, As, Pb, and Zn in environmental samples and foodstuffs grown in the vicinity of the mines in Goseong, Korea, and evaluated potential health risks among local residents. Soils near the mines exceeded the soil quality standard values of Cu, As, and Zn contamination. The concentrations of Cd, Cu, Pb, and Zn in crop samples collected from the study area were significantly higher than those of the reference area. Some rice samples collected from the study area exceeded the maximum permissible level of 0.2 mg Cd/kg. The intake of rice was identified as a major contributor (≥75%) to the estimated daily intake among the residents. The average estimated daily intakes of metals were, however, below the provisional tolerable daily intake. more...

Objectives : This research examined the Patient Hygiene Performance(PHP) index according to smoking and tooth brushing behavior, in order to analyze how they influence the oral hygiene. Methods : This research used PHP index and the structured questionnaire. The subjects were 203 men in their 20`s who visited K university`s dental hygiene department for oral prophylaxis from March to July of 2012. For data analysis SPSS WIN 12.0 was used. Results : 1. The average PHP index of all experimented subjects was 2.66, a very poor level. The PHP index according to general characteristics, smoking, drinking, and exercise showed statistical significance(p more...

Objective: Building materials can generate radon in indoor environments. This study aims to assess the radon concentrations of studio apartments around a university. Methods: 25 studio apartments around a University in Gyoungsan, Korea were measured for concentrations of radon. We evaluated the radon concentrations by using short-term continuous radon monitors at the studio apartments around the university, and analyzed the correlation between indoor radon concentration and factors affecting it, such as year of construction. Results: The average concentration of radon was 2.03 pCi/L(75.11 ) in the studio apartments. This radon level was lower than the radon standard for public use facilities in Korea and US EPA`s standard of 4 pCi/L. However the measured radon levels were much higher than those previously reported in conventional dwellings. There was a statistically correlation between year of construction and radon concentrations in studio apartment buildings. Conclusion: It is suggested that recently built studio apartments might be constructed with phosphogypsum board that features higher radon emissions, and occupants are highly exposed to radon. more...

The purposes of this study were to investigate the impact of microenvironment concentrations on personal exposure by season and city, and to develop statistical models to predict personal exposure to nitrogen dioxide (NO2). Personal exposures, residential indoor, residential outdoor and workplace indoor levels of NO2 were measured in four cities in Korea (Seoul, Daegu, Asan and Suncheon) using a passive sampler for five weekdays. The measurements were conducted in summer and winter during 2008–2009. Average personal NO2 exposures were 20.5 ppb in summer and 18.6 ppb in winter. The average personal exposures of NO2 and residential indoor levels were the highest in Seoul and the lowest in Suncheon both summer and winter. Personal exposure was significantly different by season. Personal exposure was significantly correlated with residential indoor concentration in all cities. The personal exposure estimated by residential indoor, workplace indoor and outdoor levels explained 38% and 41% of the measured personal exposure variance in summer and winter, respectively. The low correlation may be due to the longer time spent in other microenvironments in the Korean population. Personal exposure was significantly correlated with working day and city. Correlation between the estimated personal exposure and measured personal exposure was significantly associated with the season and city. The model can provide reasonable estimation of population exposure with appropriate microenvironmental concentrations and time activity data. However, season- and city-specific models should be considered. more...

The assessment of personal exposure is a critical component in population-based epidemiologic studies of air pollution. This study was conducted to apply and compare the four exposure estimation methods of individual-level to air pollution concentration in a cohort including 2,283 subjects in Gwangyang, Korea. Individual-level exposure of air pollution were estimated using multiple approaches, including average across all monitors, nearest monitor, and spatial interpolation by inverse distance weighting and kriging. The mean concentrations of PM 10 , NO 2 , SO 2 , CO, O 3 by four exposure estimation methods were slightly different but not significantly different from each other. Cross-validation showed that kriging was more accurate than other exposure estimation methods because kriging has probably predicted individual exposure levels equivalent to residential locations after estimating the parameters of a model according to the spatial surface of air pollution concentration. These data support that spatial interpolation methods may provide better estimates than selecting the value from the nearest monitor and averaging across values from all monitors by reflecting spatial attributes of air pollution on personal level.Key words: Air pollution, Cross-validation, Estimation method, Interpolation method more...

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. more...

Accurately measuring the usage patterns of consumer products (CPs) is important to conduct realistic exposure assessments. We determined the exposure factors for 18 consumer products: household bleach, mold stain remover, all-purpose cleaner, washing machine cleaner, air conditioner cleaner, glass cleaner, drain cleaner, adhesive remover, liquid snow chain, tire shine spray, wheel cleaner, rain repellent, car wax spray, leather polish, furniture polish, anti-fog product, fabric waterproofing spray, and rust inhibitor. Field survey staff visited homes and collected product use information via face-to-face interviews. In total, 10,000 participants (5010 men and 4990 women) aged 15 years and older completed the questionnaire. Household bleach had the highest use rate of 47.4% and use rates for the other products ranged from 0.8 to 21.7%. The use rates of many CPs differed by age group and gender. Many household cleaning products were used regularly, but some products, such as air conditioner cleaner and liquid snow chain, were used in specific seasons or for specific purposes; therefore, they were used less frequently compared to cleaning products. These exposure factor data will be useful as input data for exposure and risk assessments and setting safety guidelines. more...

Spatial interpolation is employed to improve exposure estimates and to assess adverse health effects associated with environmental risk factors. Since various studies have reported that high ozone (O3) concentrations can give rise to adverse effects on respiratory symptoms and lung function, we investigated the association between O3 levels and lung function using a variety of spatial interpolation techniques and evaluated how different methods for estimating exposure may influence health results for a cohort from an industrial complex (Gwangyang Bay) in South Korea in 2009. To estimate daily concentrations of O3 in each subject, four different methods were used, which include simple averaging, nearest neighbor, inverse distance weighting, and kriging. Also, to compare the association between O3 levels and lung function by age-groups, we explored ozone’s impacts on three age-related groups: children (9–14 years), adults (15–64 years), and the elderly (≥65 years). The overall change of effect size on lung function in each age group tended to show similar patterns for lag and methods for estimating exposure. A significant negative association was only observed between O3 levels and FVC and FEV1 for most of the lag and methods in children. The largest effect of O3 levels was found at the average for the lung function test day and last 2 days (0–2 days). In conclusions, the spatial interpolation methods may benefit in providing individual-level exposure with appropriate temporal resolution from ambient monitors. However, time-activity patterns of residents, monitoring site locations, methodological choices, and other factors should be considered to minimize exposure misclassification. more...

Objectives: Controversy regarding the relationship between exposure to Agent Orange and disease has progressed for more than four decades, both at home and abroad. Recently, the allegation by US veteran Steve House of the burial of Agent Orange at the US Army base Camp Carroll located in Waegwan-eup, Korea, has emerged. We reviewed published articles and reports related to Agent Orange. Methods: Articles and reports were collected online using the keywords ‘agent orange’ and ‘health’ and then reviewed. Results: A number of epidemiologic studies have reported disease outcomes due to exposure to Agent Orange, while others were unable to establish a link to the injuries of veterans of the Vietnam War. This can be explained by the fact that accurate exposure assessment should be carried out since exposure misclassification in epidemiologic studies can affect estimates of risk. In the case of the burial of Agent Orange at Camp Carroll, an exposure pathway could be through underground water supplies, which differs from the cases of Vietnam and Seveso in Italy. Conclusion: There still remains a dispute among academics regarding the relationship between exposure to Agent Orange and disease, although Agent Orange is a highly toxic chemical. This dispute indicates that accurate exposure pathway and exposure assessment is needed. more...

Personal exposure to particulate matter of aerodynamic diameters less than 2.5 μm (PM2.5) can be affected by various factors. The purpose of this study was to determine the impact of activity pattern and the contribution of each microenvironment to personal PM2.5 exposure. Technicians carried a nephelometer for PM2.5 while engaging in scripted time location activities. The scripted activities of 10 different population groups were based on time activity patterns of the Seoul population in Korea. A total of 58 daily PM2.5 personal exposures were available for analysis. The average PM2.5 personal exposure was 19.8 ± 15.3 μg m−3. The average personal exposure of each population group ranged from 9.8 to 43.1 μg m−3. High peak and average concentrations were observed in restaurants and bars; such high concentrations were due to secondhand smoke and cooking with charcoal on tables. The residential indoor level of the nine microenvironments was the largest contributor to personal exposure. The contributions from residential indoor, non-residential indoor, transportation, and outdoor levels were 36.2%, 53.4%, 6.7%, and 3.7%, respectively. The contributions of microenvironments varied among population groups; these variations suggest that the impact of activity pattern on personal exposure is significant. more...

This research had been conducted from May to October 2007, studying 110 residents of G, Y, H industrial area in Jun-nam province. It is designed to understand the difference in levels of indoor, outdoor and personal exposure to VOCs(benzene, toluene, Ethylbenzene) and a health risk assessment was conducted to see if there was any fatal cause from carcinogenic or non - carcinogenic elements from a case group and a control group in all areas as well as each different area. In the case of benzene in the air, the geometric levels for the case group are indoor, outdoor and personal exposure; a higher than for the control group. As a results of the Monte - Carlo study about benzene, it shows that the case group’scarcinogenicity is higher than that of the control group and it also shows that, on the CTE, RME condition and Monte - Carlo analysis, all subjects are seen to exceed the carcinogenicity tolerance 10 -6 of US EPA. In the case of toluene, ethylbenzene on the CTE, RME condition and Monte - Carlo analysis, these do not exceed the non - carcinogenic standard of 1, but toluene in RME condition for both groups’ personal exposure and the indoor and personal exposure of ethylbenzene in Monte - Carlo show that these seem to exceed the standard. more...

Bisphenol A (BPA) and triclosan are synthetic phenolic compounds to which the general public can be extensively exposed via consumer products and environmental contamination. In this study, we assessed exposure to BPA and triclosan in the Korean adult population aged 18–69 based on the Korean National Human Biomonitoring Survey conducted in 2009. Relying on data from 1870 representative Koreans, we found that the geometric mean urinary concentrations of BPA and triclosan were 1.90 ng/ml [95% confidence interval ( CI ): 1.81–1.99] and 1.68 ng/ml (95% CI : 1.48–1.90), respectively. The creatinine-adjusted geometric means of BPA and triclosan were 1.79 μg/g creatinine (95% CI : 1.70–1.90) and 1.58 μg/g creatinine (95% CI : 1.39–1.81), respectively. About 99.8% of the Korean adult population had urinary concentrations of BPA and about 92.6% of the Korean adult population had urinary concentrations of triclosan above the level of 0.05 ng/ml (limit of detection, LOD). Urinary BPA concentrations were higher in residents of rural areas, whereas urinary triclosan concentrations were significantly associated with cigarette smoking. These findings suggested that most Koreans had detectable levels of BPA and triclosan in their urine and that the body burden of BPA and triclosan varied according to demographic and geographic factors. more...

This study analyzed the concentration of the heavy metals(Cd, Hg, iAs) of urine(n=576) from May, 2007 to Oct 2007. The subject was residents in G, Y, H industrial area, Jeollanam-do, in which exposure due to the adjacency of the industrial complex. As to the heavy metal concentration in the urine of the residents in the whole exposed region and the comparing region, the content of cadmium, mercury, and inorganic arsenic in the exposed region group were 1.23, 1.85, and 8.80µg/g_ct respectively, and those of the comparing region group were 1.87, 2.00, and 8.93 µg/g_ct respectively, which indicates that the concentration of the comparing group was higher than that of the exposed group. The heavy metal concentration for each age group increased in proportion to age except those under 10 for some substances(p more...

【Perceived air quality (PAQ) is defined as evaluation of indoor air satisfaction and comfortable sensory by occupants. However, there are differences between criteria of indoor pollutants and lowest sensory thresholds. In this study, we compared indoor PAQ by questionnaire with measured benzene, toluene and nitrogen dioxide ( $NO_2$ ) concentrations in home indoors. The $NO_2$ concentration was the highest in Seoul, while benzene and toluene were the highest in Asan. Average PAQ score in winter was higher than that in summer. Significant correlations between PAQs of home indoor air pollution and measured pollutant concentrations were not shown and correlation coefficients (r) ranged between -0.453】 more...

Information on time spent in microenvironments has a critical role for personal exposure to environmental pollutants. Unlike several large-scale studies in Western countries, no comprehensive research on time-activity patterns for exposure assessment has been conducted in Korea. We investigated determinants of residential indoor and transportation times of individuals over 10-years old in the Korean population. The population-based study collected time-activity patterns of 31,634 Koreans for two consecutive days. The residential indoor and transportation times were collected for a weekday and a weekend day. The impact of sociodemographic factors on time-activity was assessed using multiple linear regression models. The residential indoor times were 14.23 h for the weekday and 16.13 h for the weekend and shorter than those in Western countries. The transportation times were 1.75 h for the weekday and 1.68 h for the weekend day. The most significant factors in residential indoor time were employment status, age, monthly income, and gender for the weekday and employment status and gender for the weekend day. The factors in transportation were gender, employment status, and monthly income for the weekday and gender, employment status, age, and marriage status for the weekend day. Determinants of the time-activity pattern need to be taken into account in exposure assessment, epidemiological analyses, and exposure simulations, as well as in the development of preventive strategies. As Korean population activity patterns are substantially different from those in Western countries such as USA, Germany, and UK, this information could be critical for exposure assessment in Korea and other Asian countries.Journal of Exposure Science and Environmental Epidemiology advance online publication, 28 April 2010; doi:10.1038/jes.2010.23. Language: en more...

The aim of this study was to evaluate the indoor/outdoor levels of volatile organic carbons (VOCs) using prediction for 26 apartment houses that are less than 4 years old (ALT4) and/or more than 4 years old (AMT4) in three different cities. The mass balance equation and linear regression analysis were employed to estimate source strength factor and decay constant simultaneously to identify characteristics of indoor air quality of VOCs. We failed to build prediction models for benzene and/orm-xylene compounds because benzene andm-xylene were below the detection limits in the indoor air. The estimation by linear regression for toluene showed a more appropriate fit (R2=0.707) with the Asan data than other two fits for Seoul and Daegu. more...

Indoor air quality at classrooms is of special concern since students are susceptible and indoor air problems can be so subtle that it does not always produce easily recognizable health effects. The main objectives of the study were to investigate the time-activity pattern of school students, to determine the sources of poor indoor air quality in schools, and to demonstrate how indoor air quality in schools causes adverse health effects such as headache, upper airway irritation, fatigue, and lethargy. Recent articles ranging from 1987-2009 related to school indoor air quality were systematically reviewed. Building-associated health effects can increase student absences from school and degrade the performance of children while in school. The reduced ventilation rate was associated with a decreased ability to concentrate along with increased adverse health symptoms. There was an association between residential proximity to busy roads and a variety of adverse respiratory health outcomes in children. Consequently, the current findings suggest the need for control strategy for school indoor air pollutants with multidisciplinary approach methods because Korea has no other natural resources except manpower especially. more...

Because of the building is made airtight, Indoor Air Quality(IAQ) is go from bad to worse. There are many source of indoor pollution in any home. These include irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. Such immediate effects are usually short-term and treatable. In this study was measured and analyzed VOCs exposure levels and characteristic of Indoor air pollutant from new apartments in Korea. VOCs were measured indoor pre-residential and residential in new apartment and analyzed GC/MS. The concentration levels of indoor respirable TVOC were found to be higher than those of outdoor TVOC for new apartments. Before occupation, the average indoor and outdoor concentrations were 1498.61 ug/m3 and 468.38 ug/m3, respectively. After being occupied, the average indoor and outdoor concentration were 847.04 ug/m3 and 102.84, respectively. The concentrations of TVOC in new apartments before occupation were shown in the order of Toluene(328.12 ug/m3) > m,p-Xylene(163.67 ug/m3) > Ethylbenzene(80.70 ug/m3)>o-XYlene (67.04ug/m3). In addition, the TVOCs concentrations after occupation were also found in the order of Toluene (272.28 ug/m3) > m.p-Xylene(121.79 ug/m3) > Ethylbenzene(53.92 ug/m3)>O-Xylene(24.94 ug/m3). As a result, the concentrations of VOCs in new apartment houses were shown to be affected by indoor environment according activity patterns. So new apartments need to be controled in indoor air quality so that the residents can have more comfortable and healthier living environment. more...

This study was conducted in industrial area. The level of nitrogen dioxide was measured indoor, outdoor, work and personal in an study area within 5 km from source of pollution and control area 15 km farther from August, 2006 to September. The followings are the summary of this research. The concentration of the indoor and the outdoor levels in the industrial area are 18.416.35 ppb, 18.513.26 ppb each, and the indoor/outdoor concentration rate is 0.99. The concentration of in the workplace is 18.5910.16 ppb, and the individual exposure rate is 18.805.71 ppb. The concentration of the indoor and the outdoor levels control area are 12.573.82 ppb, 9.682.16 ppb each, and the indoor/outdoor concentration rate is 1.33. The personal exposure rate is 14.4910.06 ppb. The residents of the each area and those of the comparative area spend 80.9% and 76.9% each their time in the indoor. It shows they spend most of their time in indoor. The predictions of the individual exposure rates in the industrial area and the comparative area are 15.106.14 ppb and 10.523.82 ppb each, The concentration levels measured by passive sampler are 18.805.71 ppb and 14.4910.34 ppb each. The result of the research is the analysis of the personal exposure rate in indoor, outdoor and workplace of industrial area. This research may bo used as a basic data to manage and to establish the plan for gas of the industrial area. more...

The objective of this study is to investigate the relationship between five air pollutants (PM(10), SO(2), NO(2), O(3), CO) measured on the daily basis, and adverse health symptoms using epidemiological surveillance data. The generalized estimated equation (GEE) model, a logistic regression analysis model, was used to estimate the effects of air pollution on children's daily health symptoms, focusing on the morbidity including both respiratory and allergic symptoms in four different cities. Analysis of the effects of each pollutant on children's respiratory and allergic symptoms demonstrated that CO affected all symptoms in all the study areas. When the concentration of SO(2) and NO(2) was elevated, upper respiratory symptoms increased significantly. In contrast, when the concentration of O(3) rose, the symptoms decreased significantly. The relationship between measured concentrations and health symptoms was site-dependent for each pollutant. more...

Indoor air quality can be affected by indoor sources, ventilation, decay and outdoor levels. Although technologies exist to measure these factors, direct measurements are often difficult. The purpose of this study was to develop an alternative method to characterize indoor environmental factors by multiple indoor and outdoor measurements. Using a mass balance model and regression analysis, penetration factor (ventilation rate divided by the sum of ventilation rate and deposition constant) and source strength factor (source strength divided by the sum of ventilation rate and deposition constant) were calculated using multiple indoor and outdoor measurements. Subsequently, the ventilation rate and generation rate were estimated. Mean of ventilation rate was 1.41 ACH in houses, assuming a residential N02 deposition constant of 0.94 . Mean generation rate of was 16.5 ppbv/hr. According to house characterization, inside smoking and family number were higher generation rates, and apartment was higher than single-family house. In conclusion, indoor environmental factors were effectively characterized by this method using multiple indoor and outdoor measurements. more...

In this study, in order to analyze the air quality of the indoor environments of schools, we measured the indoor, outdoor and personal exposure concentration level of for 40 classrooms(20 old, 20 new) in chungnam area from June 22 to July 19 and from November 21 to December 30, 2003. 1. Old classrooms contained more dust than new classrooms; the average of respirable dust is for new classrooms while for old one. The exposure concentration level of respirable dust in new classrooms were in summer higher outdoors than indoors. The values were indoors , outdoors , and personal . Meanwhile in winter indoors had a higher concentration level than outdoors, the values being indoors , outdoors , and personal . 2. Cr concentration level within dust was slightly higher in summer indoors () and outdoors () than winter indoors () and outdoors (), but in personal concentration level, winter was higher. The results of this research show insufficient understanding of health risks from indoor air pollution, and shows possible health problems to students from school indoor air pollution. As such, a logical and systematic education program for students about the importance of indoor air quality should be carried out. Also the results of concentration level measurements emphasize the need for regular measurements of indoor / outdoor and personal concentration level. New classrooms in particular needs to be used after measuring pollutants and safety, and requires installation of a ventilation device in all classrooms to improve air quality. more...

The 5% CoOx/TiO2 catalyst, well-characterized earlier, consisting of complete CoTiOx overlayers on Co3O4 nano-particles (“Type A”) after calcination at 843 K but of clean Co3O4 particles (“Type B”) after a continuous wet oxidation of trichloroethylene (TCE) at 310 K forca. 6 h, has been used to investigate the influence of operating variables on the activity and the stability of the Type B Co3O4 particles during wet catalysis. At 310 K, the catalyst exhibited a 48% steady-state conversion with a transient behavior in activity up toca. 1 h on stream. As the reaction temperature increased, higher performances were achieved and the transient period disappeared, which might be due to easier decapsulation of the Type A Co3O4 particles at higher temperatures to form the Type B Co3O4 particles very active for this wet oxidation reaction. All wet activities were equal to those based on the concentration of Cl− ions produced, implying the complete oxidation of TCE to HCl and CO2, and significant decrease in pH occurred because of the HCl formation. The supported CoOx was very stable for the wet oxidation at 310 K, even forca. 36 h, and XPS measurements of samples of the catalyst following the wet oxidation for desired hours were in good agreement with our earlier proposed model for CoOx species. more...