• Journal of Environmental Science International
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• v.13 no.7
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• pp.627-635
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• 2004

Evaluated were household THMs exposure associated with the use of municipal tap water treated with chlorine and with ozone-chlorine. The current study measured the THMs concentrations in the tap water and indoor and outdoor air in the two types of household, along with an estimation of THMs exposure from water ingestion, showering, and the inhalation of indoor air. Chloroform was the most abundant THMs in all three media, yet no bromoform was detected in any sample. Contrary to previous findings, the fall water THMs concentrations exhibited no significant difference between the chlorine and ozone-chlorine treated water. However, the spring median chloroform concentration in the tap water treated with chlorine (17.6 ppb) was 1.3 times higher than that in the tap water treated with ozone-chlorine (13.4 ppb). It is suggested that the effects of the water parameters should be considered when evaluating the advantage of ozone-chlorine disinfection for THMs formation over chlorine disinfection. The indoor air THMs concentration trend was also consistent with the water concentration trend, yet the outdoor air THMs concentrations did not differ significantly between the two types of household. The indoor to outdoor air concentration ratios were comparable with previous studies. The THMs exposure estimates from water ingestion, showering, and the inhalation of indoor air suggested that, for the residents living in the surveyed households, their exposure to THMs in the home was mostly associated with their household water use, rather than the indoor air. The THMs exposure estimates from tap water ingestion were similar to those from showering.

• Journal of environmental and Sanitary engineering
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• v.21 no.1 s.59
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• pp.58-65
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• 2006

This study is measured in at ozone concentrated places in school and outside of school where places that use copy machine and the others do not use one. Library copy room, Search room, Y-Copy, J-copy, R-shop are the places using copy machines and Search room, K-apt, J-billiard hall are the opposite. The measurement was held three times a day-the morning, the afternoon and the evening-once for each at indoor and outdoor. 8 places were lower than domestic ozone concentration standard(0.06ppm). The indoor ozone concentration average was the highest in Search room of school and was the lowest in Library restroom. The outdoor ozone concentration average was the highest in J-billiard hall.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.2
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• pp.188-197
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• 2016

Objectives: The purpose of this study was to evaluate the ozone exposure levels and the variations in ozone concentration in a semiconductor fabrication facility and office in relation to the ozone concentration in the outdoor air. Methods: This study was performed in an office, semiconductor fabrication facility(such as etching, diffusion, diffusion plenum), and outdoors from June to August, 2015. Measurements were taken six times at the same places using an active sampler(pumped) and real-time equipment. Ozone monitoring by the active sampler method and analysis were carried out by OSHA Method ID-214. Real-time measurement was carried out by ozone measuring equipment using a non-dispersive ultraviolet absorption method. Results: Ozone concentrations in the semiconductor fabrication facility and office were 0.7~7.1 ppb in area samples and 0.72~4.07 ppb in real-time measurement, which were 0.88~8.88% of the occupational exposure limit. The concentration of ozone generated by a laser printer in the office was less than 2 ppb. There was not a significant difference between ozone concentrations before and after using the laser printer. The indoor/outdoor concentration ratio(I/O ratio) in the semiconductor fabrication facility and office was 0.05 and 0.06, respectively. Conclusions: All the samples contained ozone levels lower than the occupational exposure limit and it was confirmed that the concentration of outdoor ozone had no significant effect on indoor ozone concentration.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.5
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• pp.87-92
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• 2000

The purpose of this study is to investigate Ozone which we have to contact in our daily lives. Recently Ozone becomes a serious pollutant in the inside and outside. To select th indicator plants or the purifier plants for air pollution caused by ozone, this stud has been conducted with interior landscape plant of 10 species. The results are as follows; 1) The visible demage by Ozone was firstly observed on Viburnum awabuki among 10 species, and it occurred after the lapse of 10, 8 and 4 hours on 0.5, 1.0 and 2.0 ppm ozone treatment, respectively. The first symptom of visible demage appeared on chlorosis or blotting of leaves, then progressed on necrosis of leaves. 2) On the other hand, Litsea japonica and Ardisia japonica were so resistant against Ozone fumigation that they were not demage independently of Ozone concentration till the lapse of 60 hours. 3) Chlorophyll contents were decreased by the increased Ozone concentration. At this time, grana destruction was observed. The most sensitive plant to ozone was Viburnum awabuki, and we suggest that Viburnum awabuki would be possible one to use for the indicator plant. The most resistance plant to Ozone was Litsea japonic and Ardisia japonica, we suggest that Litsea japonica and Ardisia japonica would be possible to use for the purifier plant for Ozone pollution.

• Journal of the Korean Society of Radiology
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• v.10 no.3
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• pp.171-180
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• 2016

This study was to evaluate the change in characteristics of concentration of ozone after exposure to high energy radiation in linac room. Background ozone concentration of linac room was measured and compared to ozone concentration around linac room. Background ozone concentration of linac room was mean $17.4{\pm}7.9ppb$. It was 50% of the ozone concentration($36.8{\pm}22.3ppb$) around linac room(p<0.05). The concentration of ozone after exposure to high energy radiation in linac room was elevated to double of background ozone level, intensity after exposure. with exposure time concentration of ozone increased proportionally. It showed maximum level at 130~180seconds and slowed a tendency to saturate. It required more than 10 minutes for ozone concentration in linac room to drop to ozone concentration around linac room. The concentration of ozone after exposure to high energy radiation is high enough to cause specific physical symptoms, such as acute dyspnea or chest pain due to dry cough. Exposure to high concentration of ozone in sealed linac room can aggravate pulmonary disease, so special attention is needed.

• Particle and aerosol research
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• v.7 no.1
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• pp.1-8
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• 2011

In this study, the formation of nanoparticles by a reaction of ozone with the volatile organic compounds(VOCs) emitted from a commercial home cleaner liquid was investigated using a $1-m^3$ reaction chamber($1{\times}1{\times}1m$). The home cleaner liquid was found to contain many VOCs, particularly terpenes. Some of these VOCs are known to readily react with ozone, forming indoor secondary pollutants. The correlation of particle concentration and reacted ozone concentration was examined with injections of three different ozone concentrations; 50, 100 and 200 ppb. The secondary nanoparticles were formed faster, with their numbers and mass concentrations becoming higher on increasing the concentration of ozone injected.

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.601-607
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• 2013

The purpose of this study was to identify the effects of ozone pollution on the one woody species and two indoor plants in controlled environment. Pinus densiflora, Spathiphyllum patinii and Epipremnum aureum seedlings were exposed in both control and ozone chambers to investigate photosynthetic rate, water use efficiency, antioxidative enzyme activities such as GR(Glutathione reductase) and APX(Ascorbate peroxidase) activity and leaf anatomical response. Ozone was fumigated 8 hours for a day with 30 ppb concentration for 50 days. Pinus densiflora seedlings showed no significant difference on photosynthetic rate, water use efficiency, antioxidant enzyme activity during ozone exposure. Ozone concentration (30 ppb in this study) is not high enough to generate ozone damage on Pinus densiflora species. In contrast, ozone generally altered photosynthetic rate, antioxidant enzyme (especially GR) activity and leaf anatomy in two indoor species (Spathiphyllum patinii and Epipremnum aureum) exposed in ozone chamber were significantly differ from those of control in every measurement. These data suggest that two indoor species(Spathiphyllum patinii and Epipremnum aureum) are more sensitive to ozone than Pinus densiflora.

• Journal of Environmental Science International
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• v.16 no.8
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• pp.1001-1009
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• 2007

Passive sampler is a simple and cost-effective measuring equipment for ambient and indoor air pollution. We studied the performance of a short term (1 hour mean concentration) ozone passive sampler which was coated with a colorant (indigo carmine) to a filter substrate. Acetone and sulfamic acid added ozone passive sampler was investigated to measure short term mean ozone concentration. Ozone response and interference of criteria air pollutant($SO_2,\;NO_2$, CO) on a short term ozone passive sampler was tested through experimental chamber. The results show sulfamic acid added passive ozone sampler have good response in ozone exposure. Interference of $NO_2$ gas is larger than other two criteria gases.

• Journal of Environmental Health Sciences
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• v.32 no.2 s.89
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• pp.171-178
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• 2006

The objectives of this study were to investigate the formation of trihalomethanes(THMs) and to compare the concentration level of THMs of swimming pools water by different disinfection methods such as chlorine, ozone-chlorine, and salt brine electrolysis generator (SBEG). The concentration of chloroform was the highest in the chlorine system, and the SBEG was the highest in the production of bromodichloromethane (BDCM), dibromochloromethane (DBCM) and bromoform. The average concentration of total trihalomethanes (TTHMs) in three disinfection systems were $64.5{\pm}27.4mg/l(SBEG),\;43.8{\pm}22.3mg/l(chlorine)$, and $30.6{\pm}16.1mg/l(ozone-chlorine)$, respectively. In chlorine and ozone-chlorine disinfection system, chloroform concentration was highest, followed by BDCN, then DBCM. In the SBEG, TTHMs was composed of 42% of chloroform, 28.9% of bromoform, 15.1% of BDCM and 14% of DBCM, respectively. The strongest correlation was obtained in the levels of chloroform and TTHMs in chlorine, and ozone-chlorine disinfection systems from both indoor and outdoor swimming pools ($r=0.989{\sim}0.999$, p<0.01). In the SBEG, the levels of BDCM and TTHMs showed a good correlation (r=0.913, p<0.01). In chlorine and ozone-chlorine disinfection systems at indoor swimming pools, pH, TOC and $KMnO_4$ consumption showed strong correlation with chloroform and TTHMs concentrations (p<0.01). In the SBEG, pH and TOC were also strongly correlated with chloroform (p<0.01). pH and TTHMs were correlated as well (p<0.05).

• Journal of Environmental Health Sciences
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• v.23 no.2
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• pp.57-63
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• 1997

This study was carried out to find the adverse health effects of ozone by papers, the potential indoor sources of ozone by papers, and then the removal mechanism of ozone by experiments. The exposure of individuals to excessive levels of ozone both in the industrial and ambient environment is a continuing public health concern. Ozone indoors may play a role in generating secondary pollutants that may have adverse health effects. The removal efficiency of ozone was studied by (1) the effect of concentration on breakthrough time, (2) the effect of flow rate on breakthrough time, (3) the effect of adsorbent's weight on breakthrough time, (4) the effect of temperature on breakthrough time, (5) the application of Langmuir's isotherm equation in using activated carbon. The followings are the conclusions that were derived from this study. 1. In the effect of concentration on breakthrough time, the adsorption capacity of activated carbon was inversely proportional to ozone concentratuion (0.1, 0.2, 0.3 ppm). 2. In the effect of flow rate on breakthrough time, the service life of activated carbon was inversely proportional to flow rate (2, 8, 14l/min). 3. The difference in removal efficiency of ozone between weights(100 mg and 150 mg) was seen. And when weight of activated carbon was 100 mg and 150 mg, pressure loss was 4-5mmHg and 6-7mmHg, respectively. It is required to study relations among flow rate and adsorbent's weight and ventilation quantity, too. 4. Generally, Langmuir's equation, one of the oldest and most used frequently isotherm equation, applies to chemisorption. In case of ozone, when the weight of activated carbon was 70 mg and temperature 40, slope(1/a) was $6.25\times 10^{-1}$ and intercept(1/ab) was $1.9\times 10^{-4}$ (average r=0.94).