The topic of indoor air quality has attracted great interest since urban dwellers spend over 90% of their time indoors, such as public facilities, public transport and homes. In this study, the changes and current status of indoor air quality management and improvement policies for public facilities in Korea were discussed. Furthermore, we investigated the concentration and contamination status of indoor air pollutants based on the indoor air quality guidance and inspection report from 2007-2017 published by the Ministry of Environment, Korea. As a result, we found that while the PM10 concentration in public facilities decreased consistently, there was no clear change in the CO2 concentration. The HCHO concentrations were high in museums, art galleries, and postpartum centers, etc. The child care centers showed a high concentration of TCB. In conclusion, we suggested that it is necessary to focus on target substances according to the type of facility to manage indoor air quality efficiently. Intensive management and monitoring are particularly needed in child care centers to improve the indoor air quality.

The purpose of this study was to evaluate indoor air pollutants of children’s facilities in libraries. The indoor pollutants, which were managed under the “Indoor Air Quality Control Standards” and “Environmental Safety Standards for Children’s Activity Zones,” were measured within five months. The new environmental pollutants such as phthalates and pesticides were also measured. The pollutant-measuring device was installed in children’s spaces in libraries and children’s libraries of the metropols. The result of investigating indoor pollutants showed that the concentration of fungus and floating bacteria had low distributions due to the use of air purifiers in all libraries. The concentration of HCHO and TVOCs was also measured lower than the environmental standards in well-ventilated libraries. On the other hand, phthalates and pesticides were detected in all libraries. In the case of heavy metals, they were mainly found in the finishing materials of the library walls and floors. As a result, indoor pollutants are managed under court receivership. On the other hand, phthalates and pesticides, which are not regulated by environmental standards should be managed because they were detected in all libraries.

The number of complaints of odor in urban area has been increased due to mixed industrial areas of odor-related factories and municipal waste treatment odor-producing facilities located in adjacent residential regions. In this study, the characteristics of odor were reviewed according to two types of complaint from regions in Incheon area. In this study, the characteristics of odor were reviewed in two patterns of odor complaints in Incheon area such as the complaints are maintained high continuously and are increased in recent period. International city with largescale residential areas with the environmental facilities and redevelopment of residential regions with the adjacent industrial complexes and other odor emission sources were analyzed. Based on these characteristics, the odor management measures of major odor generating sources in order to improve urban environment were discussed with reducing odor complaints effectively.

The urban expressway is widely used to avoid traffic jams in highly-populated urban areas. However, vehicle exhaust can be easily transported to the neighboring area including residential buildings. In this study, we investigated the transport and penetration of vehicle exhaust into the nearby high-story residential building. Black carbon (BC) and lung deposited surface area (LDSA) concentrations were monitored every 1 min using an aethalometer (AE51, Magee) and a nanoparticle aerosol monitor (AeroTrak 9000, TSI), respectively. For comparison, the measurement was carried out in both the living room and balcony of the apartment from January 18 to January 25, 2016. The CO2 concentration indicated the presence of residents in the living room and transport of vehicle exhaust from the roadway in the balcony. Its diurnal variation showed a significant difference between weekdays and the weekend, implying the different time activity of residents and traffic volume. BC and LDSA concentrations were 1.4±1.5 μg/m3 and 53.9±45.0 μm2/cm3 indoors, and 1.9±1.0 μg/m3, 76.2±34.5 μm2/cm3 outdoors, respectively. The indoor to outdoor concentration ratios range from 0.6 to 0.8, indicating the significant influence of outdoor vehicle exhaust. The highest concentrations of BC and LDSA were observed in the morning rush hours, except for those indoors during the weekend. In particular, the outdoor effect is significant during the morning rush hours. Indoor air quality management is urgently needed for residents living near the urban expressway.

Several analytical measurement techniques have been developed over the years for ammonia (NH3). However, the field monitoring of NH3 still remains a significant challenge owing to the wide range of possible environmental conditions and NH3 concentration. In this regard, it is imperative to ensure the quality control of techniques to measure the NH3 emission levels reliably. A present study was conducted to compare the five analytical methods for the measurement of atmospheric NH3 via validation tests under laboratory and field conditions. The analytical instruments applied in the present study were based on wet chemistry, gas detection tube, electrochemical sensor, photoacoustic spectroscopy, and cavity ring-down spectroscopy. The reproducibility and linearity of all the analyzed methods were observed to be high with the relative standard deviation and coefficient of determination (R2) being 10% and > 0.9, respectively. In the case of wet chemistry and high NH3 concentration, the measured NH3 results were found to be close to the actual standard gas levels. Response times of electrochemical sensor showed faster from the instruments utilized more than one year and the high NH3 concentrations. In the field tests, NH3 concentration showed higher in the manure storage tank compared with the pig-pen. In both cases, the NH3 concentration levels measured by gas detection tube were found to be quite different from that of wet chemistry. It was proposed that such differences in NH3 concentration could arise due to the inherent instrumental characteristics and the variations in air velocity during sampling/measurement. The periodic instrumental maintenance, verification, replicate analyses, and suitable consideration of environmental factors should be considered for a more reliable measurement of NH3 concentration under real field conditions.

The cooking-generated particles are major indoor sources of air pollution. Recently, the performance of the range hood is focused on particle removal performance. Range hood with an auxiliary air supply system can improve the fine and ultrafine particles removal efficiency by making a supply air during cooking activities. The particles were measured in the experimental building by varying ventilation types. Only operating range hood during the cooking activities was not enough to reduce the cooking-generated particles. Despite operating range hood systems, fine and ultrafine particle concentrations were maintained when cooking was finished. The range hood with a make-up air supply system can reduce the indoor particle concentration below background conditions when those systems were operated after cooking. In this study, the assessment of cooking-generated particle removal efficiency of the range hood with an auxiliary air supply system was conducted. The removal efficiency of ultrafine particles showed trends similar to the removal efficiency of fine particles.

This study was conducted to analyze the characteristics of odorous components that have been generated from the downtown sewer system based on twenty-three survey items for complex odor and designated offensive odor. As a result of the research, the contribution rates for the causative materials of the odor indicated 73.5% of hydrogen sulfide, 26.0% of methyl mercaptan, 0.4% of dimethyl sulfide, and 0.1% of dimethyl disulfide. The occurrence for the odorous materials according to sampling site revealed data of which contribution rates showed 56.9% of hydrogen sulfide and 36.8% of methyl mercaptan from the combined sewer system in the business district; whereas the combined sewer system in the residential area showed 16.4% of dimethyl sulfide and 4.3% of dimethyl disulfide. The seasonal occurrence rate of the odor materials was observed higher in summer and lower in winter And, the combined sewer system in the business district recorded the highest concentration of 4.61 ppm of hydrogen sulfide among the sampling site. An hourly occurrence rate for the odor materials consistently showed the greatest increase between 11:00 and 14:00 at each location and showed a decreasing tendency afterward.

The use of printing inks containing organic solvents by the master, offset and screen printing process implies the release of volatile organic compounds (VOCs) to the work environment. In this study, the volatile content of inks was evaluated by using a thermogravimetric analyzer (TGA), in which the solvent is evaporated. And, to identify the the characterization of VOCs emissions from printing inks, air samples were collected in a thermal extractor (TE) and analyzed by thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS). Weight loss curves suggest that there are two main stages, such as dry fastening and chemical curing. As the result, the first stage of mass loss (below 100oC) was due to VOC evaporation. At this stage, master and offset inks are slightly stable thermally up to 100oC, but screen inks weight loss increases distinctly beyond 25oC. The volatile content is higher in screen inks than in the master and offset inks. The results of the mass-specific TVOC emission rate of the master, offset, and screen inks were 6.3 μg/(g·h), 8.4 μg/(g·h), and 212.2 μg/(g·h), respectively. Then the TVOC emission rate of the screen inks was 25~33 times higher than that of the master and offset inks. The main species were 1-Ethyl-2-pyrrolidinone, 1,2,4-Trimethylbenzene, 1,2,3-Trimethylbenzene, 1,2,4,5-Tetramethylbenzene, 1-Methoxy-2- propanol, Decane, Undecane, and Nonane.

The concentrations of odor and volatile organic compound (VOC)-inducing substances were measured using selected ion flow tube mass spectrometers (SIFT-MS). SIFT-MS can continuously measure the concentration of odor-causing substances and VOCs in real time without pre-treatment steps. Measurements were conducted during the day and at night at 10 spots in the chemical block of the Sihwa industrial complex. Similar measurement results were observed in the daytime and nighttime for materials except methyl ethyl ketone with high concentrations. A high concentration of hydrogen sulfide was also measured at night. It is expected that an amount of emissions of VOCs and odor-causing substances under the absence of inspection can be traced if measured at other industrial complexes in vulnerable times.

In this study, we evaluated the filtering effect of the fine dust mask. Our objective research has secured credibility in the private sector. The performance of domestic fine dust masks is evaluated by three dust collection efficiencies, inspiratory resistance, and leakage rate according to KF grade in the health mask standard guidelines issued by the Ministry of Food and Drug Safety. Based on this, eight types of fine dust masks were evaluated for dust collection efficiency and face intake resistance. All masks showed good performance as the collection efficiency was 90%. The higher the KF grade, the higher the collection efficiency, but the inspiratory resistance had no correlation with the grade. According to the manufacturer's operation method, masks below the standard value may be distributed. Masks that are currently on the market have shown results that can be trusted. However, we hope that the system will be improved to validate whether the masks that meet the threshold are still being distributed.

This study was conducted to separate microorganisms with excellent odor component decomposition ability from nature. Microorganisms growing sulfur and ammonia compounds as substrates were isolated and identified in the tidal flat of Suncheon Bay. The strain YUN4 cultured on ammonia and sulfur compound substrates was found to have 100% genetic homology to Streptomyces fulvissimus. The optimum growth temperature of YUN4 was 20oC to 40oC, and the optimum pH was investigated in the range of pH 5 to pH 9. In addition, in order to evaluate the ability to reduce odor, after mixing the culture strain with each concentration of 1%, 5%, and 10% in the malodor generating sample, the efficiency of malodor reduction was evaluated after 30 minutes. As a result, the ammonia decomposition efficiency was 82.4%~93.9%, and hydrogen sulfide was 88.7%~94.9%.

Statistical analysis for the 703 air purifiers certified by Korea Air Cleaning Association from 2003 to 2019 was performed. Sixty-one percent of the products had an area coverage of 15 m2~30 m2 and the median value of the total products was 37.6 m2. The number of certified products by the top five manufacturers was 325, which corresponds to 46.2% of the total products. The median value of the clean air delivery rate (CADR) of the 703 products was 4.8 m3/min but the number of air purifiers over the value increased to 62.5%~66.3% since 2018. The odor removal ratio showed a median of 86.0% which was higher than the certification criteria but had large differences in efficacy in the five test compounds. Removal efficiencies of each compound in terms of the median and ratio to the average value showed acetate > formaldehyde > toluene > ammonia > acetaldehyde in descending order with large variances. The median noise level average value from five positions of air purifiers was 47.7 dB(A). However the medians of the top position and the front, where purified air was vented out, were relatively higher in 49.8 dB(A) and 48.2 dB(A), respectively. Noise level ratio to noise criteria had a median value of 96.4%, which showed that most of the noise levels were distributed near the criteria limit. The probability of the noise level at 100% of the criteria was calculated ton 0.232, which indicated excess noise levels.

Odor emitted from the degradation process of food waste is a common cause of public complaints, and appropriate odor treatment methods need to be implemented. In this study, a hybrid plasma catalyst system was applied to treat individual odorous compounds including acetaldehyde and hydrogen sulfide, which are known to be major odor compounds produced from food waste. MnOx catalysts were prepared by varying Mn/support loading ratios, and surface analyses showed that the Mn_5% catalyst achieved the highest performance because dominant manganese oxide species on the surface of the catalyst was found to be Mn2O3, Using the catalyst, the removal rate of hydrogen sulfide steadily increased as the space velocity in the MnOx catalyst reactor decreased. Meanwhile, the removal rate of acetaldehyde did not increase significantly when decreasing the space velocity more than 24,000 hr-1. Following the catalyst experiments using the individual odorous compounds, the hybrid system was applied for testing odor treatment of actual food waste. The actual food waste study showed that both hydrogen sulfide and acetaldehyde were steadily removed; hydrogen sulfide was removed almost completely during the initial 30-minute period, while the acetaldehyde removal was started after the decrease of hydrogen sulfide. In addition, it was confirmed that the dilution-to-threshold for odor reduced from 2,080 D/T to 300 D/T during the initial period. In conclusion, the plasma and Mn2O3 catalyst system can be applied in food waste collection containers to effectively control odor problems.

This study was conducted to evaluate the applicability of a carrier media with natural minerals as packing material in a biofilter to remove odor-causing compounds. The carriers were prepared by mixing powdered zeolite, barley stone, and clay. They have a pellet type with a length of 5m m to 10 mm, 3.2 m2/g of a specific surface area, and 0.04 cm3/g of a pore volume. The adsorption capacity and the biodegradation by biomass formation on the media were experimented with toluene and ammonia as the test compounds. The carrier possessed the ability to adsorb toluene and ammonia. The adsorption capacity of toluene and ammonia at the inlet concentration of 100 ppmv was 58 g/g and 96 g/g, respectively. In the biofilter using the carrier as the packing material, the biofilter performances were different depending on the supply of moisture and liquid-nutrient. The critical loading was found to be 33.13 g/m3/hr for toluene removal and 6.5g /m3/hr for ammonia removal even when no nutrients were supplied. The proposed material has been confirmed to be capable of adsorbing inorganic and organic compounds, and can be effectively applied as packing materials for the biofiltration.