• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.175.1-175.1
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• 2016

In recent, tract infections such as atopic dermatitis, allergic rhinitis and a respiratory disease are increasing, giving rise to the atmospheric pollution, inflow of micro-size dust and side effect of humidifier disinfectant. In this context, the environment-friendly technology is required to eliminate airborne pathogens. We propose solution of the previous problems, making use of Radical Mist Generator (RMG). Existing technologies of air purification using a gas discharge produce harmful substances such as ozone, NOx, etc. However, the RMG uses a pure water as a plasma forming material. The RMG sprays the water mist, which contains reactive radicals to sterilize microorganisms. RMG is comprised of a power supply, plasma electrodes and a nozzle. In order to analyze the electrical characteristic and concentrations of reactive radicals, we employ an oscilloscope and a titration method. To test the sterilization effect of RMG, we used E.coli. We confirmed that E.coli was killed over 90%. Eventually, we expect that RMG can be promising tool for a purified system.

• Journal of Environmental Health Sciences
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• v.43 no.4
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• pp.247-256
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• 2017

Objectives: The deaths of Korean victims exposed to the disinfectant CMIT/MIT have remained unresolved. This is mainly due to a lack of concordance between the few available toxicity tests and the abundant epidemiological data, making it difficult to establish a cause-and-effect relationship. Therefore, this study was carried out to investigate any potential associations between CMIT/MIT exposure and death. Methods: Groups of experimental and control C57BL/6 mice were instilled (in the trachea) with chloromethylisothiazolinone/methylisothiazolinone (CMIT/MIT) using a visual instillobot. CMIT/MIT was instilled over a period of three days and eight weeks, respectively, to achieve acute and chronic exposures. A threshold dose-response model was applied for estimating the threshold level as one line of evidence for a causal association between CMIT/MIT and death. Results: An acute exposure of 1.2 mg ai/kg/day of CMIT/MIT was estimated to reflect the threshold for death. The dose-response curve with this threshold showed a very steep slope and a narrow range of CMIT/MIT exposures. The narrow range of CMIT/MIT exposures, in particular, indicated an evident boundary between survival and death, thus implicating a strong causal association. A similar threshold dose-response relationship observed following acute exposure was also seen following chronic exposure to CMIT/MIT. Airborne disinfectant exposure was visible as minimal or mild lung damage with no fibrosis, as shown by histopathological tests. However, many observations are considered to be functional respiratory tract or lung failure due to death, as observed in necropsies of the mice that died due to CMIT/MIT exposures. Conclusions: There are two strong lines of evidence for a causal association between death and CMIT/MIT exposure: 1) The threshold dose-response curve, with a very steep slope and a narrow range of CMIT/MIT exposures showing a visible boundary between survival and death; and 2) many cases of functional respiratory or lung failure.

• Journal of Digital Convergence
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• v.15 no.4
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• pp.181-190
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• 2017

Recently, safety accidents of daily necessities such as humidifier disinfectant, mobile phones, and infant diapers, have occurred frequently. To protect consumers from these accidents, product safety management is required, and a product risk assessment tool is needed to evaluate the degree of safety of the product. In this paper, we have constructed RAS, which is a system that can evaluate product risk based on injury information of product accident in Korea Consumer Agency. RAS consists of an injury information analysis system for analyzing accident-related information and a risk assessment system for assessing risk using information derived from the system. The Bayesian network - based probabilistic method is applied to reflect the causal relationships that affect product risk in the risk assessment process. We used RAS to evaluate 33 children's products and compared them with the results of EU RAPEX RAG. Subsequent tasks include reducing the subjectivity of the input of the accident impact scale, and linking the above two systems.

• Journal of Environmental Health Sciences
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• v.46 no.3
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• pp.285-296
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• 2020

Objective: The objective of this study was to describe the characteristics of exposure to humidifier disinfectants (HDs) and their association with the presence of a person who experienced the adverse health effects in general households in Korea. Methods: During the month of December 2016, a nationwide online survey was conducted on adults over 20 years of age who had experience of using HDs. It provided information on exposure characteristics and the experience of health effects. The final survey respondents consisted of 1,555 people who provided information on themselves and their household members during the use of HD. Exposure characteristics at the household level included average days of HD use per week, average hours of HD use per day, the duration within which one bottle of HD was emptied, average input frequency of HD, amount of HD (cc) per one time used, and active ingredients of HD products (PHMG, CMIT/MIT, PGH, or others). The risk of the presence of a person who experienced adverse health effects in the household was evaluated by estimating odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for monthly income and region using a multiple logistic regression model. Subgroup analyses were conducted for households with a child (≤7 years) and households with a newborn infant during HD use. Results: The level of exposure to HD tended to be higher for households with a child or newborn infant for several variables including average days of HD use per week (P<0.0001) and average hours of HD use per day (P<0.0001). The proportion of households in which there was at least one person who experienced adverse health effects such as rhinitis, asthma, pneumonia, atopy/skin disease, etc. was 20.6% for all households, 25.3% for households with children, and 29.9% for households with newborn infants. The presence of a person who experienced adverse health effects in the household was significantly associated with average hours of HD use per day (P_trend<0.001), duration within which one bottle of HD was emptied (P_trend<0.001), average input frequency of HD (P_trend<0.001), amount of HD per one use (P_trend=0.01), and use of HDs containing PHMG (OR=2.23, 95% CI=1.45-3.43). Similar results were observed in subgroup analyses. Conclusion: Our results suggest that level of exposure to HD tended to be higher for households with a child or newborn infant and that exposure to HD is significantly associated with the presence of a person who experienced adverse health effects in the household.