This study was to assess the lifetime cancer and non-cancer risk on exposure to volatile organic compounds (VOCs) and formaldehyde of worker and user at public facilities in Korea. We measured the concentrations of formaldehyde and VOCs in indoor air at 160 public buildings that 5 kinds of public facilities (30 hotel, 30 fitness center, 25 gosiwon, 30 reading-room and 45 video-room) all over the country. There were estimated the human exposure dose and risks with averages of the using-time and frequency for facility users and office workers, respectively. Carcinogens (benzene and formaldehyde) were estimated the lifetime excess cancer risks (ECRs). Non-carcinogens (toluene, ethylbenzene, xylene, and styrene) were estimated the hazard quotients (HQs). HQs of four non-carcinogens did not exceed 1.0 for all subjects in all facilities. Higher HQs of toluene were observed at the reading-room. The average ECRs of formaldehyde and benzene for facility worker and user were 1×10^-4~1×10^-6 level in all facilities. The estimated ECRs for reading-room were the highest and the fitness center and gosiwon were the next higher facilities. Because lifetime ECRs of carcinogens exceeded 1×10^-4 for facility worker in the most facilities, risk management of formaldehyde and benzene in the facilities was necessary. IAQ guidelines should be determined strictly to prevent occurrence of disease caused by poor IAQ beforehand.

This studies were measure the cortisol from salivary and serum of fire-fighters, who are relatively always exposed to highly dangerous and unsafe working conditions in which they should bring a fire under control or rescue people in danger situations et cetera, therefore both physically and mentally stressed-out, and comparatively analyzed the correlation between the two cortisol levels. The salivary and serum samples of 133 active fire fighters. These were collected at 8:30am, when leaving for work. The salivary cortisol analysis was carried out with enzyme immunoassay, and the serum cortisol analysis utilized chemiluminescence immunoassay. On the morning of testing, the salivary cortisol concentration was 1.92±0.73(0.51~5.85)㎍/㎗, while the cortisol concentration of serum was 14.93±4.23(4.45~25.85)㎍/㎗. Results were grouped according to ages, smoking, drinking habit, and duty type. Higher smoking and drinking produced a statistically significant increase in salivary and serum cortisol concentration. Cortisol concentrations according to type or duty followed by emergency rescue, fire suppression, rescue, miscellaneous. There is a statistically significant correlation between salivary and serum cortisol concentrations. The results show that a significant correlation between salivary and serum cortisol concentrations exists in fire fighters. It is judged that noninvasive methods salivary cortisol could be used in place of serum cortisol to measure cortisol levels when considering factors such as convenience of sample collection and cost.

This paper presented experimental results for circulation type UV-TiO₂ photocatalytic oxidation process. We have developed UV-TiO₂ photocatalytic oxidation process with activated carbon to control odor and VOCs in indoor and industrial applications. In this study, common indoor air pollutants, namely ammonia, formaldehyde, hydrogen disulfide, toluene were selected to investigate their efficiencies for UV-TiO₂ photocatalytic oxidation. In high concentration test, the decomposition efficiency was high in order as ammonia, toluene, formaldehyde, hydrogen disulfide. Three type of individual processes are tested for ability to increase decomposition efficiency. UV-TiO₂ photocatalytic oxidation combined process with activated carbon was excellent among the three type processes without reference to gas species. It was considered that this circulation type process will overcome short retention time for treatment for UV-TiO₂ photocatalytic oxidation. It will promise that this circulation type UV-TiO₂ photocatalytic oxidation combined process can apply indoor and industrial applications to remove odor and VOCs quickly.

The conversion of coal fly ash into zeolites contributes to the mitigation of environmental problems and turns this by-product into useful material. In this work, zeolitic sorbents for CO₂ adsorption were prepared by waste fly ash from Boryeong coal power plants through the alkali fusion method including hydrothermal treatment at various ratios of NaOH/FA and NaAlO₂/FA. In addition, in order to improve the adsorption capacity for CO₂ molecules a few metal cations were impregnated into the synthesized zeolitic sorbents through the ion exchange. The fusion step could decompose the fly ash to very small amorphous particulate zeolite forms. The fly ash was converted into Na-P1 type with 0.5 NaOH/FA and Na-A type from the ratio of 0.53, NaAlO₂/FA. Although the crystallinity of Na-A increased with increasing temperature, Na-A was transformed into sodalite at 140℃. Thus, the optimum reaction temperature was determined to be 100℃. Alkali metal and alkaline earth metal cations were impregnated into the synthesized zeolite Na-P1 and Na-A through ion exchanged method. The completed zeolitic sorbents were applied to adsorption the CO₂. As a result of the examination, Ca²⁺ was found to be the best for CO₂ adsorption owing to its electrostatic interactions and acid-base surface properties.

We measured indoor, outdoor, and personal exposure concentrations of ozone (O₃) at 54 households in Gwangyang from June to September, 2009. The results are as follows. The concentration of ozone in outdoor, 16.53±5.72 ppb, was observed two times higher than the concentration of ozone in indoor, 8.22 ± 4.60 ppb. The similar arithmetic average ozone were obtained in exposed and controlled areas, 15.16 ± 1.45 ppb and 15.25 ± 1.94 ppb, respectively. The ozone concentration of an individual smoker was 24.89 ± 7.11 ppb, which was higher than that of a non-smoker, 21.01 ± 11.79 ppb. The indoor occupant density elevated ozone concentrations. The relatively low concentration of ozone was observed in a house with air conditioner (8.59 ± 4.04 ppb) than a house without the unit(10.07 ± 6.43 ppb).

This study aims to provide preliminary review for standardization of methods for evaluating reduction performance of pollution-reducing building materials and to select commercially available pollution-reducing building materials for assessing their current status. The ISO 16000-23 and -24 standards were used as references for standardizing the test methods. The sub test categories—stability of the supply air concentration, type of the supply air, and supply air concentration—which were not included in the standards were selected and conducted for the purpose of this study. Five (5) wall materials and 2 ceiling materials were tested for formaldehyde reduction performance and 3 wall materials were tested for toluene reduction performance. The study included experimental review of the essential test criteria such as stability of the supply air, internal stability of the chamber, and recovery rate. The samples tested exhibited some reduction performance for formaldehyde but little reduction performance for toluene.

In order to meet the national standard and public needs for Seoul Metro subway, air purification has been taken into a consistent consideration with the addition of high quality control facilities. This work focuses on the review of the cost effectiveness to improve the air filtration of an MVAC (mechanical ventilation & air conditioning) in a field subway. The inflow PM₁₀ and PM_2.5 into the test MVAC chamber were 19.4 kg/yr and 8.9 kg/yr respectively. It corresponds to the environmental cost of 5,857,000 won for PM₁₀ and 6,608,000 won for PM_2.5 every year. While the current filtration system collects approximately 55% of the inlet PM₁₀ and 35% of PM_2.5, a new lay-out showed 80% for PM₁₀ and 55% for PM_2.5. The new design presented the environmental benefit for PM10 with 1,464,000 won, whilst the additional cost required 3,192,744 won. In the future, however, the increase of environmental benefits for the indoor dust over the atmospheric aerosols will more or less compensate the potential cost.