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

Oxygen*

No abstract available.
Oxygen*

In order to estimate interfering effects of mercury and lead on biochemical oxygen demand (BOD), BOD in 18 effluent samples were measured under three different concentrations of mercury and lead. The results obtained were as follows: 1. Biochemical oxygen demand(BOD) was decreased under the presence of mercury and lead, with parallel correlation of mercury concentration. 2. High correlations were noted between original BOD concentration and decreasing amount of BOD when concentrations of mercury or lead were increased. 3. When the lead concentration was high, the close correlation was observed between total organic carbon(TOC) and decreasing amount of BOD. 4. There was a negative correlation between TOC/BOD ratio and decreasing amount of BOD when the mercury concentrations were high.
Oxygen*

No abstract available.
Oxygen

Synergetic effects for p-nitrophenol degradation were observed in the ozonation with ultrasonic enhancement. The enhancements of removal rate for p-nitrophenol and TOC were around 116% and 294% respectively in comparison with the individual ultrasound and ozonation systems. The synergetic phenomenon is attributed to two physicochemical mechanisms: (1) Ultrasound decomposes ozone causing augmentation of the activity of free radicals; (2) Ultrasonic wave increased the concentration of O(3) in solution because of ultrasonic dispersion.
Hydrogen Peroxide ; chemistry ; Nitrophenols ; chemistry ; Oxygen ; chemistry ; Ozone ; chemistry ; Solutions ; Sonication ; Waste Disposal, Fluid ; Water Pollution

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

BACKGROUND: It is well known that ultraviolet light(UVL) may cause skin cancer, decrease immune function and promote skin ageing. It is also known that an increase of chlorofluorocabons as air pollution, which csuses the depletion of ozone of the earth in ihe atmosphere, enables harmful ultraviolet-B(UVB) to reaeh the surface of the earth more easily: The purpose of this study is to determine the harmful effect of UVB on the skin by observing coicurrently the morphologieal snd biochemical changes in the UVB irradiated skin. OBJECTIVE: The animal used was the hairless mouse(Hr+/Kud) which are considered to be the most suitable for a UVB irradiation experiment. The Fluorescent sunlamp(Toshiba FL, 20SE, Toshiba electrie Co., Tokyo, Japan) was used as a source of UVB. METHOD: The skin of the back and ear was irradiated by an increasing doses of UVB. In morphological changes, the slteration in keratinocytes and Langerhans cells in cell number and morphology were observed. In biochemical changes, activities of tte superoxide dismutase and eatalsse, which scsvanges reactive oxygen species(O and H) producec in the skin by UVB irradistion were assayed. RESULT: Sunburn cells appeared st 60mJ/cm of UVB and increased in number in proportion to the UVB irradiation with dose dependent pattern. The Langerhans cell decreased in number in proportion to UVB irrsdiation in dose dependent manner(half maximum dose was 60mJ/cm), and was not found at 1J/cm. The morphological changes of the Langerhans cells, such as a loss of dendrites and granulation, were noticed at 60mJ/cm of UVB irradiation. The enzyme activity of catalase decreased in proportion to UVB irradiation. The enzyme activity of SOD was not changed by UVB irradiation, however, it significantly increased at 1000mJ/cm UVB irradiation. CONCLUSION: This study suggest that UVB irradiation to the skin causes a reduction in the immune funetion and alters the normal biochemical function of the skin.
Air Pollution ; Animals ; Atmosphere ; Catalase ; Cell Count ; Dendrites ; Ear ; Keratinocytes ; Langerhans Cells ; Mice ; Mice, Hairless* ; Oxygen ; Ozone ; Skin ; Skin Neoplasms ; Sunburn ; Superoxide Dismutase ; Ultraviolet Rays

BACKGROUND: Welders tend to be exposed to a variety of hazards including metal fumes, toxic gases, electricity, heat, noise, and radiation such as ultraviolet and infrared light. Noxious gases generated during welding include carbon monoxide, ozone, and nitrogen oxide. Although the effects of metal fumes have been well studied, few reports have investigated the influence of noxious gas exposure in welders. CASE REPORT: We encountered a patient who developed non-cardiogenic pulmonary edema within a day after fairing up a steel plate with an oxygen/LPG torch. The patient was a 43-year-old female who complained of dyspnea which became exacerbated the following morning. Her chest X-ray and chest CT scan showed an extensive ground glass opacity which was more prominent in the both upper lungs. Both her symptoms and chest X-ray findings improved. We attributed the patient's symptoms to non-cardiogenic pulmonary edema caused by nitrogen dioxide exposure, by reasoning that: 1) the patient's clinical course and radiologic findings suggested pulmonary edema 2) the event happened following fairing work with oxygen/LPG torch that usually induces a high concentration of nitrogen dioxide, and 3) the other possible causes of pulmonary edema could be excluded. CONCLUSION: Nitrogen dioxide-induced pulmonary edema should be considered in oxygen torch contrary to arc welding.
Adult ; Carbon Monoxide ; Dyspnea ; Electricity ; Female ; Gases ; Glass ; Hot Temperature ; Humans ; Lung ; Nitrogen Dioxide ; Nitrogen* ; Noise ; Oxygen* ; Ozone ; Pulmonary Edema* ; Steel ; Thorax ; Tomography, X-Ray Computed ; Welding