Hazardous air pollutants such as NO2, VOCs and PM10 were measured Daegu, Korea in major micro-environments,where housewives spend the most of their time, and personal exposure times were estimated by using time activitypatterns and exposure scenarios. The major microenvironments of housewives were selected using the ‘Time-UseSurvey’ conducted by the National Statistical Office in Korea in 2009. A total of 4,514 (weekdays) and 3,063(weekends) housewives were recruited for the ‘Time-Use Survey.’ It seems that housewives are spending about80% of their time in the house, and about 5% of their time outdoors during weekdays and weekends. The indoor/outdoor ratio of the average concentration of NO2 was more than 1, which indicated that the source was indoors.Toluene was shown to have higher concentrations indoors than outdoors. Ethylbenzene and xylene displayedsimilar characteristics to toluene, and the concentration ratio for indoor/outdoor was shown to be 1.29 ± 0.76 and1.04 ± 0.45, respectively, higher concentrations indoors. Based on the results of the time activity patterns ofparticipants, 3 kinds of exposure scenarios were formulated. The spent time and air concentration in eachenvironment were assumed as normal and lognormal distribution, respectively. And then the Monte-Carlosimulation was conducted. According to the result of the simulation, the exposures to hazardous air pollutantsrevealed an increasing pattern as housewives visits other indoor environments such as supermarkets.

This study was performed to measure the concentration of odorous compounds and dilution ratio values at each part of the anaerobic digester process with composting facilities using swine manure and food waste. Complex odors, ammonia, volatile fatty acids and sulfur compounds were measured at each part of the process. Complex odors measured during swine manure storage, food waste storage and in the digested liquid tank, were 35,312 Odor Unit(OU), 39,086 OU and 17,733 OU, respectively. The odor contribution index was calculated by the concentration of odorous compounds during each process divided by the threshold limit. As a result, the major odorous compound that appeared during swine manure storage, food waste storage and in the digested liquid tank was hydrogen sulfide. On the other hand, the major odorous compound in the other processes was ammonia. The overall average concentrations of ammonia were highest in the digested liquid tank(337 ppm) and the separated liquid tank(131 ppm). Wastewater treatment process(10.9 ppm) and deodorization process(11.6 ppm) revealed the lowest concentration of ammonia. The overall average concentration of total volatile fatty acids(TVFAs) was 102.8 ppb during food waste storage and among the TVFAs, the main element was propionic acid(66.1 ppb). Sulfur compounds were only detected during swine manure storage, food waste storage and in the digested liquid tank. The dominant sulfur compound was hydrogen sulfide during swine manure storage(96.3 ppm) and methyl mercaptan during food waste storage(17.7 ppm) and dimethyl sulfide during food waste storage(34.5 ppm).

Asbestos was a general term applied to certain fibrous minerals long popular for their heat-resistance, tensile strength, acoustic insulation and inexpensive price. Despite its many uses, asbestos is a hazardous material. Inhalation of asbestos fibers can cause serious health problems, such as lung cancer, asbestosis and mesothelioma. According to the compliance regulations for asbestos-related materials in Korea, all kindergartens have to be inspected for asbestos materials before April 2014. The purpose of this study is to investigate the distribution of asbestos containing materials in kindergartens in Gwangju, Korea. We investigated 93 kindergartens between January and May in 2014. Asbestos types and contents were analysed using the polarized light microscopy (PLM). Kindergartens facilities that featured ACM(Asbestos Containing Material) included ceiling textiles that contained chrysolite/amosite in amounts between 2 and 5% and gaskets that contained chrysolite in amounts between 15 and 35%. Also, wall cement flat boards contained chrysolite in amounts between 10 and 15%. In this study, risk assessment of asbestos material showed that all kindergarten materials were classified as Low grade when assessed by the Korea Ministry of Employment and Labor guideline method.

Indoor pollutants seem to have a negative affect on people from vulnerable households who are considered to be weak by the department of environmental health, such as the elderly, infants, children, patients, and pregnant women. In this study, the concentrations of pollutants were measured, especially those pollutants that endanger vulnerable households such as PM10, HCHO, TVOCs, TBC and fungi. The measurements were taken from September to October of 2013 in the Chungnam area. The results were as follows: PM10 33.2 μg/m3, HCHO 20.35 μg/m3, VOCs 132.30 μg/m3, TBC 562.71 CFU/m3 and fungi 362.04 CFU/m3. In the case of TBC and fungi, there were excessive concentrations at 30.9% and 49.3% compared to the standards set by WHO. In the case of fungi, buildings built before the 1980s showed a concentration of 446.23 CFU/m3, those built in the 1980s and 1990s had a concentration of 320.21 CFU/m3 and those built in the 2000s had a concentration of 313.43 CFU/ m3 indicating that fungi concentration was higher when the building was older. The correlation analysis between indoor air pollutants and factors affecting indoor concentrations indicate that HCHO (r = 0.423), TVOCs (r = 0.329), and humidity (r = 0.359) showed a significant difference (p < 0.01). The current study focused on vulnerable households that were unable to protect themselves from indoor pollutants and where poor living circumstances prevailed such as households that do not receive much sunlight; thus, more attention and focus needs to be given to these particular households

This study tried to survey air quality inside and outside the schools where are located in about 5km of industrial complex targeting aldehyde, PM10, PM2.5. Also, the aim was also to examine both a change in indoor air after 3 years and within 3 years of addition and improvement, and a change according to season. It collected specimens at totally 20 places. Aldehyde was analyzed through HPLC. PM10 and PM2.5 were measured by using Met One 831. Formaldehyde and Acetaldehyde were detected with 42.1 μg/m3 and 5.7 μg/m3 at the school where is located inside 5km of the industrial complex, and were detected with 55.0 μg/m3 and 6.8 μg/m3 at the school where is located outside 5 km. This could be confirmed to have been detected more highly in the indoor air than the outdoor air regardless of the distance from the industrial complex. Most substances were indicated to be higher by about 150% in the indoor air within 3 years than the indoor air following 3 years of addition and improvement. However, PM10 and PM2.5 were measured with 32.6 μg/m3 and 14.9 μg/m3 after 3 years and were gauged with 22.4 μg/m3 and 14.2 μg/m3 within 3 years. Seeing a seasonal change, Formaldehyde and Propionaldehyde were detected with 5.5 μg/m3 and 1.0 μg/m3 in spring, 7.7 μg/m3 and 1.6 μg/m3 in summer, and 8.3 μg/m3 and 1.9 μg/m3 in autumn. This could be confirmed the tendency of growing according to season.

The object of this study is to investigate the relationship between the air dilution sensory test and the threshold odor number (TON) method for evaluating the odor of domestic wastewater, plating plant wastewater, food plant wastewater and lake water. The dilution factor of raw wastewater evaluated by the air dilution sensory test was in the order of food plant > plating plant > domestic > lake, and that evaluated by the threshold odor number method was in the order of food plant > domestic > plating plant > lake. The same results were obtained when the raw wastewater and lake water were diluted 2 and 5 times with pure water. The relative geometric standard deviation determined from the threshold values of each panel on the air dilution sensory test was much larger than that calculated from results derived from the threshold odor number method. The relative geometric standard deviation obtained from samples with a low dilution factor was greater. There was a very good linear correlation (correlation coefficient = 0.968~1.000) between the air dilution sensory test and the threshold odor number method. But, the reduction in odor intensity (the slopes of regression curves) by dilution was dependent on the types of the odor-emission sources.

In this study, the growth kinetics of sulfur oxidizing bacteria, Acidithiobacillus thiooxidans, and the effect of dissolved oxygen were determined in low pH conditions for the effective removal of high concentrations of hydrogen sulfide. A dual growth kinetic was applied to identify the microbial growth rate at different hydrogen sulfide and oxygen concentrations in the liquid. A modified Monod-Gompertz equation was deemed most appropriate to examine the growth kinetic parameters of A. thiooxidans. The half saturation constants of hydrogen sulfide and oxygen for the modified Monod-Gompertz equation were found to be 0.9 and 1.1 mg/L, respectively. In addition, a bioreactor model, where the Monod-Gompertz equation was modified, was applied to simulate dissolved oxygen concentrations required for the removal of hydrogen sulfide. As a result, the dissolved oxygen concentrations were 0.5, 1.0, 1.5, and 3.3 mg/L, which were necessary to remove hydrogen sulfide to less than 10 ppm at the influent concentrations of 100, 500, 1000 and 3000 ppm, respectively. The required minimum dissolved oxygen concentrations under various conditions including reactor volume, gas retention time, and microbial concentrations can be determined using the numerical model developed in this study.

In this study, this researcher measured the indoor concentration of radon in elementary schools located in Chungcheongnamdo, and conducted a questionnaire survey from June 2008 to June 2011. Indoor radon densities of elementary schools by season were 86.4 Bq/m3 in winter, 71.2 Bq/m3 in fall, 61.1 Bq/m3 in spring, and 40.5 Bq/ m3 in summer in order. Among flooring materials by construction material, the radon level of concrete was 57.8 Bq/ m3, and cement was 71.5 Bq/m3. For exterior wall materials, it was established that the density of cement, concrete, wood, and soil was 102.9 Bq/m3, 64.4 Bq/m3, 51.0 Bq/m3, and 48.7 Bq/m3, respectively. In addition, for radon densities according to distances between a detector and floors, 150 cm and under was recorded at 99.3 Bq/m3, 151 to 200 cm was recorded at 62.6 Bq/m3, and 201 cm and more was recorded at 59.2 Bq/m3 sequentially. From the results of analyzing correlations between radon concentrations and factors affecting the indoor radon concentrations in elementary schools, it was discovered that the nearer the distances to floors were and the older the construction was(r = 0.300), the higher were indoor radon concentrations. With regard to factors influencing the indoor radon concentrations in elementary schools, derived from multiple regression analysis, it was revealed that distances from floors has the greatest influence(β = 0.354, p < 0.05). And it was determined that the construction year was also a factor contributing to indoor radon levels. This had an explanation power of 27.9%.

This study was carried out to estimate odors emitted from toilets in Mugunghwa trains. Two parameters, odor intensity and odor concentration, were used for odor estimation. A direct olfactory method to observe odor intensity for 67 toilets and an air dilution olfactory method to estimate odor concentration for 6 samples were performed. Results showed that odor concentrations in toilets in trains ranged from 6 OU/m3 to 30 OU/m3, and odor intensity in 67 toilets varied from 0 degree to 3.3 degree. The results suggest that odors emitted from existing toilets should be controlled because the odor intensity in 16 toilets reached a level that resulted in complaints about the odor.