OBJECTIVETo evaluate the performance of vaporized hydrogen peroxide (VHP) for the bio-decontamination of the high efficiency particulate air (HEPA) filter unit.

METHODSSelf-made or commercially available bioindicators were placed at designated locations in the HEPA filter unit under VHP fumigation. The spores on coupons were then extracted by 0.5 h submergence in eluent followed by 200- time violent knocks.

RESULTSDue to the presence of HEPA filter in the box, spore recovery from coupons placed at the bottom of the filter downstream was significantly higher than that from coupons placed at the other locations. The gap of decontamination efficiency between the top and the bottom of the filter downstream became narrower with the exposure time extended. The decontamination efficiency of the bottom of the filter downstream only improved gently with the injection rate of H2O2 increased and the decontamination efficiency decreased instead when the injection rate exceeded 2.5 g/min. The commercially available bioindicators were competent to indicate the disinfection efficiency of VHP for the HEPA filter unit.

CONCLUSIONThis assay developed can detect all 16 β-lactams demanded by the European Union (EU). The whole procedure takes only 45 min and can detect 42 samples and the standards with duplicate analysis.

BACKGROUND: Nowadays, there are many methods to reduce microorganisms in the air, such as dehumidifier, air purifier or humidity and temperature controller. The Precise Climate Controller is an instrument for controlling humidity and temperature, a concept that is demonstrated. OBJECTIVE: To determine the efficacy of this device, in order to reduce the quantity of the fungi and bacteria in the closed system.
Air Conditioning ; Air Filters ; Aspergillus flavus ; Bacteria ; Climate ; Colony Count, Microbial ; Fungi ; Humidity

OBJECTIVE: To analyze the effect of domestic high-efficiency particulate air (HEPA) purifiers on the concentrations of indoor fine particulate matter (PM_2.5) and its elementary constituents in 20 residences in a district of Beijing during winter. METHODS: From November 2015 to January 2016, 20 residences in a district of Beijing were selected, where indoor and outdoor PM_2.5 data were collected simultaneously in three time periods according to the operating of air purifiers (Group 0 h: 24 hours before operating; Group 24 h: 24 hours after operating; Group 48 h: 24 to 48 hours after operating). The content of 21 elements in PM_2.5 samples were determined by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES). Indoor/outdoor particle concentration ratio (I/O ratios) and ΔI/O ratios were used to describe the pollution levels and the variation range of PM_2.5 and its 21 elementary constituents. One-way analysis of variance (ANOVA) for repeated measurement data was applied to compare the I/O ratios of PM_2.5 and its elementary constituents among the different groups, and Bonferroni method was used for comparison in pairs. Wilcoxon signed rank test for paired-samples was used to compare ΔI/O ratios of 21 elementary constituents with that of PM_2.5. RESULTS: The median I/O ratios of PM_2.5 in the three groups were 1.27 (P25-P75: 0.50-2.68), 0.45 (P25-P75: 0.27-1.03) and 0.36 (P25-P75: 0.28-2.48), respectively. Compared with Group 0 h, the I/O ratios of PM_2.5 in Group 24 h (P=0.042) and Group 48 h (P=0.006) decreased significantly. However, there was no significant difference between Group 24 h and Group 48 h. Significant differences were found comparing ΔI/O ratios of aluminium, ferrum and titanium to that of PM_2.5, in both Group 24 h and Group 48 h (P<0.05). No significant change was found in the I/O ratios of these three elements among the three groups before and after air purifier operating (P>0.05). Distances from residences to traffic arteries could affect I/O ratios of some elements from traffic-related source (P<0.05). CONCLUSION Domestic HEPA air purifiers could effectively reduce indoor PM_2.5 concentration, and the pollution level of PM_2.5 tend to be stable after the purifier operating for a time. The purifiers had different effects on different elements, among which most showed statistical significances.
Air Filters ; Air Pollutants ; Air Pollution, Indoor/analysis* ; Beijing ; Environmental Monitoring ; Housing ; Particle Size ; Particulate Matter ; Seasons

PURPOSE: Inhalational therapy is now one of the major method in managing asthma. Nebulizer is widely used at home nowadays, but there has been no survey on the usage of home nebulizer in Korea yet. This study was performed using questionnaires to evaluate that how the asthmatic patients use the personal nebulizer properly as an treatment tool for asthma. METHODS: Forty-six asthmatic children living in Chunlabukdo area in Korea who use the personoa nebulizer at home from October 1999 to March 2000 were enrolled. Personal history, purpose of personal nebulizer, understanding of the instruction to use were analyzed using questionnaires. RESULTS: 1) The sex ratio was not statistically significant (M : F ratio was 1.3 : 1) and the mean age was 3.7 years. 2) Thirty-seven cases (80.4%) purchased nebulizer by doctor's recommendation. 6 cases (13.1%) by personal need without doctor's recommendation and 3 cases (6.5%) by acquaintances' recommendation. 47.8% of patients purchased through small-scale suppliers. 32.6% purchased through hospital, and 19.6% through large nebulizer manufacturers. 3) Sixty-three percents of patients had an explanations about the basic instructions to use the nebulizer. Explanations on maintenance were given only in 19.6% of total and was mostly given through large nebulizer manufacturers. 4) Proper washing with sterilization took place in 54.3%, replacement of kits and air filters were done in only 15.2% of the total, but nobody was recommended annual check up. 5) There was no difference in the techniques of using nebulizers by the parents' level of knowledge about asthma. CONCLUSION: Many problems on the usage of personal home nebulizer in asthmatic children were revealed by this study. Education of patients on how to use and manage nebulizers is necessary when prescribe or sell the nebulizers.
Air Filters ; Asthma ; Child* ; Humans ; Korea ; Nebulizers and Vaporizers* ; Patient Education as Topic ; Surveys and Questionnaires ; Sex Ratio ; Sterilization

Fungi are the known sources of irritation associated with atopic diseases (e.g., asthma, allergic rhinoconjunctivitis, and atopic eczema). To quantitatively estimate their presence in the indoor environment of atopic dermatitis-inflicted child patient's houses (ADCPHs), the high-efficiency particulate air (HEPA) filters installed inside the air cleaners of three different ADCPHs were investigated for the presence of mold. The air cleaner HEPA filters obtained from the three different ADCPHs were coded as HEPA-A, -B, and -C, respectively, and tested for the presence of mold. The colony forming units (CFUs) corresponding to the HEPA-A, -B, and -C filters were estimated to be 6.51 x 10(2) +/- 1.50 x 10(2) CFU/cm2, 8.72 x 10(2) +/- 1.69 x 10(2) CFU/cm2, and 9.71 x 10(2) +/- 1.35 x 10(2) CFU/cm2, respectively. Aspergillus, Penicillium, Alternaria, Cladosporium, Trichoderma, and other fungal groups were detected in the 2,494 isolates. The distribution of these fungal groups differed among the three filters. Cladosporium was the major fungal group in filters HEPA-A and -C, whereas Penicillium was the major fungal group in the filter HEPA-B. Nine fungal species, including some of the known allergenic species, were identified in these isolates. Cladosporium cladosporioides was the most common mold among all the three filters. This is the first report on the presence of fungi in the air cleaner HEPA filters from ADCPHs in Korea.
Air Filters* ; Alternaria ; Aspergillus ; Asthma ; Child* ; Cladosporium ; Dermatitis, Atopic* ; Fungi* ; Humans ; Korea ; Penicillium ; Stem Cells ; Trichoderma

PURPOSE: High level of indoor air pollutant may cause aggravation of atopic diseases long with various allergic respiratory diseases especially in people who spend mostly of their lives indoors. The aim of this study was to evaluate the effect of air purifier on the reduction of relevant hazards in indoors and the improvement of atopic dermatitis (AD). METHODS: A total of 24 families, consisted of 18 AD families and 6 normal control families, were enrolled in this study. We examined air quality and AD severity before the installation of air purifiers and after twenty-four weeeks. The assessment of air quality included fine particles (particulate matter, PM2.5 and PM10), gaseous contaminants (CO, CO2, volatile organic compounds [VOCs], formaldehyde, NO2) and density of offloating microorganisms. Severity of AD was assessed by SCORing atopic dermatitis (SCORAD) index and transepidermal water loss (TEWL). RESULTS: At the end of study, particular air pollutants and VOCs of gaseous air pollutants decreased in both groups (P<0.01). In AD group, SCORAD index decreased from 23.45+/-4.34 to 15.42+/-6.53 (-18.5%) and TEWL decreased from 33.78+/-5.16 to 26.89+/-5.66 (-18.7%) (P<0.01 and P<0.01, respectively). However, the value of total immunoglobulin E and eosinophil did not show significant changes in both groups compared with baseline. CONCLUSION: These results suggested that air purifier may improve severity of AD by reducing air pollutants like fine particles and VOCs. Our preliminary study could provide a basis for using air purifier to prevent aggravation of AD.
Air Filters ; Air Pollutants ; Air Pollution, Indoor ; Dermatitis, Atopic ; Eosinophils ; Formaldehyde ; Humans ; Immunoglobulin E ; Immunoglobulins ; Volatile Organic Compounds ; Water Loss, Insensible

BACKGROUND: During general anesthesia, a heated breathing circuit (HBC) is used to replace the heat and moisture exchange function of the upper airway. One HBC uses an air dryer filter that employs silica gel (SG) as a desiccant. SG is capable of adsorbing many organic compounds. Therefore, we undertook an in vitro study of the adsorption of desflurane by SG filters. METHODS: An HBC was connected to an anesthesia machine, and a test lung was connected to the circuit. The test lung was mechanically ventilated with 2 or 4 L/min of fresh gas flow, with and without the air dryer filter. Desflurane was administered at a 6 vol% on the vaporizer dial setting. The experiment was repeated 15 times in each group. The end-tidal concentrations were measured during the experiments. The air dryer filter weights were measured before and after the experiments, and the times required to achieve the specific end-tidal desflurane concentrations were determined. RESULTS: Significant differences in the end-tidal concentrations of desflurane were observed between the control and filter groups (P < 0.001). The filter weights increased significantly after the experiments (P < 0.001). The times required to achieve the same end-tidal desflurane concentrations were different with the application of the air dryer filter (P < 0.001). CONCLUSIONS: The adsorption of desflurane with the use of an air dryer filter was verified in this in vitro study. Careful attention is needed when using air dryer gel filters during general anesthesia.
Adsorption* ; Air Filters ; Anesthesia ; Anesthesia, General ; Desiccation ; Hot Temperature ; Lung ; Nebulizers and Vaporizers ; Respiration* ; Silica Gel* ; Weights and Measures

Particulate matter is an air pollutant emitted from both natural and anthropogenic sources, and its adverse health effects have been well documented in time-series analyses and cohort studies. The effect size of particulate matter exposure—a roughly 0.5% increase in mortality for each 10 µg/m³ increment of short-term exposure to particulate matter with aerodynamic diameter ≤10 µm and approximately a 10% increase for each 10 µg/m³ increment of long-term exposure to particulate matter with aerodynamic diameter ≤2.5 µm—is small compared to other risk factors, but the exposure is involuntary and affects the entire population, which makes particulate matter pollution an important public health issue. The World Health Organization and Korean government have both established guidelines for particulate matter concentrations, but the Korean guideline is less stringent than that of the World Health Organization. The annual mean concentration of particulate matter in Korea is decreasing, but the trend seems to be slowing. In addition to policy efforts to reduce particulate matter emission, personal approaches such as the use of face masks and air purifiers have been recommended. Personal approaches may not solve the fundamental problem, but can provide temporary mitigation until efforts to reduce emission make progress.
Air Filters ; Cohort Studies ; Environmental Medicine ; Epidemiology ; Humans ; Korea ; Masks ; Mortality ; Particulate Matter ; Public Health ; Risk Factors ; World Health Organization

PURPOSE: Childhood asthma has a considerable social impact and economic burden, especially in severe asthma. This study aimed to identify the proportion of childhood asthma severity and to evaluate associated factors for greater asthma severity. METHODS: This study was performed on 667 children aged 5–15 years with asthma from the nationwide 19 hospitals in the Korean childhood Asthma Study (KAS). Asthma was classified as mild intermittent, mild persistent, and moderate/severe persistent groups according to the National Asthma Education and Prevention Program recommendations. Multinomial logistic regression models were used to identify the associated factors for greater asthma severity. RESULTS: Mild persistent asthma was most prevalent (39.0%), followed by mild intermittent (37.6%), moderate persistent (22.8%), and severe persistent asthma (0.6%). Onset later than 6 years of age (adjusted odds ratio [aOR], 1.69 for mild persistent asthma; aOR, 1.92 for moderate/severe persistent asthma) tended to increase asthma severity. Exposure to environmental tobacco smoke (aOR, 1.53 for mild persistent asthma; aOR, 1.85 for moderate/severe persistent asthma), and current dog ownership with sensitization to dog dander (aOR, 5.86 for mild persistent asthma; aOR, 6.90 for moderate/severe persistent asthma) showed increasing trends with greater asthma severity. Lower maternal education levels (aOR, 2.32) and no usage of an air purifier in exposure to high levels of outdoor air pollution (aOR, 1.76) were associated with moderate/severe persistent asthma. CONCLUSIONS: Modification of identified environmental factors associated with greater asthma severity might help better control childhood asthma, thereby reducing the disease burden due to childhood asthma.
Air Filters ; Air Pollution ; Animals ; Asthma ; Child ; Dander ; Dogs ; Education ; Environmental Exposure ; Humans ; Logistic Models ; Odds Ratio ; Ownership ; Risk Factors ; Smoke ; Social Change ; Tobacco

BACKGROUND: Although multiple chemical sensitivity (MCS) is a well-known disorder caused by environmental exposures, MCS caused by occupational exposure has been reported in Korea. Therefore, we report a MCS case caused by environmental exposure to ignition coal after a differential diagnosis to exclude other diseases. CASE REPORT: Since 2011, a 55-year-old woman had experienced edema, myalgia, and other symptoms when she smelled ignition coal near her workplace. She had been diagnosed with fibromyalgia syndrome(FMS) and was treated, with no improvement of symptoms. Since then, she showed the same symptoms after exposure to city gas, the smell of burning, and exhaust gas. To avoid triggering substances, she moved to a new house and used an air purifier. She quit her job in November 2012. After visiting our hospital, she underwent a differential diagnosis for FMS, chronic fatigue syndrome, and somatization disorder. She was diagnosed with MCS by the Korean version of the Quick Environment Exposure Sensitivity Inventory (QEESI). She was educated about the disease and to avoid triggering substances. She received ongoing treatment for her symptoms. CONCLUSION: This case showed that symptoms began after smelling ignition coal. After that, her triggers was increased such as the smell of city gas, burning, and exhaust gas. This case is the first reported in Korea of MCS due to environmental exposure after ruling out other diseases.
Air Filters ; Burns ; Coal* ; Diagnosis, Differential ; Edema ; Environmental Exposure ; Fatigue Syndrome, Chronic ; Female ; Fibromyalgia ; Humans ; Korea ; Middle Aged ; Multiple Chemical Sensitivity* ; Myalgia ; Occupational Exposure ; Smell ; Somatoform Disorders