Recently, exposure to sunlight is increasing due to expanded life time, outdoor leisures, and reduced sun protective ozone layer. Sunlight can produce not only benefit but also various kinds of harmful effect, such as skin carcinogenesis, photoaging and immunologic alterations, These effects can be minimized by sunscreens. This article reviews the methods to measure a suncreens efficacy and factors influencing the measurement. I. Measurement of photoprctective efficacy 1)The sun protective factor(SPF): The SPF is defined as the ratio of the UVB doses required to produce minimal erythema dose(MED) with sunscreen applied to without it. However, the exact procedures are not estabiished and the value is varied by methods. 2)Photoprotective factor A(FFA): In spite of its clinical improtance, evaluation of UVA protection rernains a problem due to its physiologic features. The methods to measure UVA protection are by the use of erythemal, phototoxic and pigmentary rections. 3)Outdoor measurement: It is ideal to measure the photoprotectiveness outdoor but a wide variation in value results from radiance sources and environmental factors. II. Factors influencing the evaluation The radiance sources, individ zal sensitivity to sunlight, product components and various environmental factors can make differences. Conclusion As more sunlight, exposure, he irnportance of photoprotection is increasing. The exact methods to measure the protectiveness of UVA and UVB should be established, especially adjusted to Korean people
Carcinogenesis ; Erythema ; Leisure Activities ; Skin ; Solar System ; Stratospheric Ozone ; Sunlight ; Sunscreening Agents

BACKGROUND: Ultraviolet light induces sunburn, ageing of the skin, pigmentation and even promotes skin cancers. As there has been a recent decrease in the ozone layer surrounding the earth, increasing attention has been given to the effects of ultraviolet light on the skin. Through human epidermis, ultraviolet light is reflected, scattered, absorbed or transmitted. In caucacians, the rate of transmitted ultraviolet light A from the epidermis to the dermis is 50% and the rate of transmitted ultraviolet light B is below 10%. OBJECTIVE: The purpose of this study was to evaluate the transmittance of UVA and UVB on Korean normal epidermis. METHODS: Pure epidermis was obtained from normal human epidermis by suction of blisters in 12 patients with vitiligo. All specimens were irradiated respectively with UVA and UVB and the amount of transmitted energy was measured. RESULTS: 1. The transmittance of UVA energy density by normal epidermis was 47.7+11.2% of irradiated UVA energy. 2. The transmittance of UVB energy density by normal epidermis was 32.4+3.4% of irradiated UVB energy. CONCLUSION: UVA energy transmission through normal epidermis of Korean is less than those of Caucacians but UVB energy transmission through nor mal epidermis of Korean is more than those of Caucacians. It is suggested that this could be an important basic data to study for photoaging and photoprotection in Korean population.
Blister ; Dermis ; Epidermis* ; Humans* ; Pigmentation ; Skin ; Skin Neoplasms ; Stratospheric Ozone ; Suction ; Sunburn ; Ultraviolet Rays ; Vitiligo

No abstract available.
Inflammation* ; Nasal Mucosa* ; Ozone*

To present a critique of the disaster management, the pre-disaster, disaster and post-disaster events surrounding the Ozone Disco fire, the worst land fire disaster in the Philippine history, that occurred on March 19, 1996 were retrieved and summarized from available and verifiable records. The disaster events were analyzed based on the principles of disaster management, particularly in the medical care of the casualties and the operational structures existing in the region at that time. The existing disaster plan of the hospital involved was included in the analysis. Conclusions were set to refocus interest in the disaster and provide basis for planning in disaster preparedness.

Humans ; Ozone ; Rhinitis, Allergic ; Rhinitis, Allergic, Perennial

OBJECTIVES: To investigate the pulmonary function changes of ozone exposure in Corona and Slitter workers exposed to an ozone level ranging from 0.022~0.061 ppm. METHODS: Forty-two subjects were exposed for 8hrs to ozone every day. We perfomed pulmonary function testing immediately before and after work and self-administered, portable peak flow meter measurements were self-conducted by the workers over a 5-day (Monday to Friday) period. RESULTS: Ozone concentrations in the workplace ranging from 0.050~0.061 ppm at Corona and 0.022~0.023 ppm at Slitter in 2006. A small decrement in forced-vital capacity were observed among Corona workers from 93.9% to 91.3% (p=0.012) and also in employment duration below ten years. We found no significant differences in before and after FVC and FEV1 among Slitter workers. All daily (Monday to Friday) peak expiratory flow rates declined in magnitude after two days of ozone exposure, compared with first day exposure. CONCLUSION: We concluded that daily ozone exposure in the workplace slightly decreased pulmonary function and that PEFR variability is greatest on the 2nd day of ozone exposure.
Employment ; Ozone* ; Peak Expiratory Flow Rate ; Respiratory Function Tests

BACKGROUND: Ozone is one of the most ubiquitous oxidant in urban air and may exacerbate respiratory diseases such as asthma. OBJECTIVE: We examined whether ozone can influence airway hyperresponsiveness induced by influenza virus-infection. SUBJECT AND METHOD: Rats were exposed to ozone, acutely to 1.0ppm and 0.25ppm for 23.5hrs. At 2hrs post cessation of ozone exposure, animals were infected with rat-adapted influenza virus intra-nasally. On day 3 post-virus inoculation, pulmonary mechanics were measured during an intravenous challenge with acetylcholine < (ACh), 100-140mg/ml in saline>. Cumulative doseresponse functions were obtained by doubling the rate of the intravenous infusion every 2min. RESULTS: ACh increased airway resistance in a dose-dependent manner. Neither of the concentrations of ozone altered the airway responses to ACh. Animals infected with virus developed hyperresponsiveness to ACh as was expected. Pre-exposure to 1.0ppm ozone for 23.5hrs aug- mented the virus-induced airway hyperresponsiveness, while 0.25ppm did not. CONCLUSION: Acute exposure to ozone can synergistically act on virus-induced airway hyperreactivity.
Acetylcholine ; Airway Resistance ; Animals ; Asthma ; Influenza, Human* ; Infusions, Intravenous ; Mechanics ; Orthomyxoviridae ; Ozone* ; Rats*

PURPOSE: The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. MATERIALS AND METHODS: One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). While control groups were immersed in distilled water for 10 min (control1) and 7 days (control7), test groups were subjected to PAA (16 g/L) or ozone rich water (4 mg/L) for 1 cycle (10 min for PAA and 60 min for ozone) per day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey's HSD test. RESULTS: Adhesive strength of Mollosil decreased significantly by application of ozone disinfection. PAA disinfection had no negative effect on the TBS values of Mollosil and Molloplast B to acrylic resin. Single application of ozone disinfection did not have any negative effect on TBS values of Molloplast B, but prolonged exposure to ozone decreased its adhesive strength. CONCLUSION: The adhesion of resilient liners to acrylic was not adversely affected by PAA disinfection. Immersion in ozonated water significantly decreased TBS of Mollosil. Prolonged exposure to ozone negatively affects adhesion of Molloplast B to denture base materials.
Acrylic Resins ; Adhesives ; Denture Bases ; Disinfection* ; Immersion ; Ozone* ; Peracetic Acid ; Water

BACKGROUND: Ozone (03) induces airway inflammation and hyperresponsiveness which are characteristic features of asthma. There have been few studies observing O3-induced increase in responsiveness of rat airway muscle. Objectives: The aims of this study were to develop an O3-induced nonallergic asthma model using rat tracheal smooth muscle (TSM) and to evaluate the role of airway epithelium on the modulation of muscle responsiveness. METHOD: Five groups of 20 male Sprague-Dawley(SD) rats were exposed to filtered air including 0.12, 0.5, 1.0, or 2.0 ppm 03 for 1 hour. Thirty minutes after the exposure, bronchoalveolar lavage (BAL) and isometric contractile responses of the isolated tracheal ring segments to KCI, acetylcholine (ACh), and electrical field stimulation (EFS) were measured. RESULTS: The percent age of neutrophils was significantly higher and that of alveolar macro-phages in BAL fluid was significantly lower in 2.0 ppm O3-exposed rats than in the control. There were no significant differences in the maximal contractile responses of TSM to KC1, ACh, EFS and in the sensitivity to ACh (ACh-EC50) and EFS (EFS-EC50) between the control group and the ozone exposed group. ACh-EC50 and EFS-EC50 were correlated positively with the percent age of neutrophils and inversely with that of macrophages. Removal of epithelium significantly increased the sensitivity to ACh in O3-exposed group, but not in the control group. CONCLUSION: These findings indicate that O3 induces neutrophilic airway inflammation, but not an increased sensitivity of TSM to ACh or EFS in SD rats. However, O3-induced epithelial damage may be associated with increased muscle response.
Acetylcholine ; Animals ; Asthma ; Bronchoalveolar Lavage ; Epithelium ; Humans ; Inflammation ; Macrophages ; Male ; Muscle, Smooth* ; Neutrophils ; Ozone ; Rats* ; Trachea

In this study, the effect of surface modification of polymethylmethacry-late[PMMA]by grafting of poly[ethylene glycol][PEG]on cell adhesion was investigated. PMMA surface was treated with ozone and then PEG-acry-late[PEGA]was graft-polymerized. Ozone treatment of the surface was car-ried out at room temperature by applying constant flow of oxygen[4.5liter/min]and 1 bar pressure. After ozone treatment, PMMA was immersed immediately in 20 wt%aq. PEG-acrylate solutions in glass ampoules. After degassing, the ampoule was sealed and kept at 60 degrees C for 24 hours to complete the graft polymerization. PMMA surface grafted with PEG revealed the enhanced oxygen content at ESCA analysis and the decreased dynamic receding contact angles. The adhesion of keratocytes onto modified PMMA was investigated. Keratocytes[4 x105cells/milliliter ]were layered on each PMMA discs which were glued to the bottom of 24-well culture plates, and cultured in a CO2 incubator for 24 hours. The adherent cells onto the surfaces were harvested by trypsinization and counted. The mean numbers of keratocytes on untreated PMMA, PEG-grafted PMMA with 1hour ozone treatment and PEG-grafted PMMA with 2 hour were 72.5 x104 and 6.5 x104 and 7.6 x104cells respectively, and there was a significant statistical difference [p=0.002], irrespective of ozone treatment period. This result suggests that surface modification of PMMA using PEG grafting may reduce etroprosthetic membrane formation of artificial cornea.
Cell Adhesion ; Cornea ; Glass ; Incubators ; Membranes ; Oxygen ; Ozone ; Polymerization* ; Polymers* ; Polymethyl Methacrylate ; Transplants ; Trypsin