2 The „bad“ ozone on the ground is very different from the „good“ ozone up high in the Stratosphere !!!!!!!!!Too much ozone in the Troposphere (on the gournd) has a very different effect and can cause severe ailments:Respiratory diseases (e.g. asthma); especially endangered are children, the elderly and people under severe physical strainInflammationNauseaChanges in blood countEffects on the nervous system (exhaustion, decline in performance).Damage to forestsCorrosion of metallic itemsDeterioration of buildings (monuments)
3 Contents UV - Radiation Skin Cancer Skin Structure The Ozone Layer CFC and Alternatives
4 What is UV-Radiation? Visible light ranges between 390nm - 770nm. UV – light is located below 390nm.UV-B and UV-C are more harmful; they do not penetrate the skin very deeply, but rather react in the Epidermis and Dermis.
5 The Spectrum of Sunrays 52% visible light 44% invisible Infrared radiation 4% UV - radiation (These are the most dangerous to skin!)
6 Consequences of Increased UV-Radiation Skin cancerExamples of other illnessesEffects on nature
7 Damage caused by radiation Damage caused by radiationThe major dangers are inflammatory reactions (sunburn) and damages to the DNA of the skin cells, which can lead to skin cancer.Benign melanomataand malignant melanomataare the two possible types of skin cancer that can develop. The malignant melanomata are also called black skin cancer.
9 The malignant melanoma - black skin cancer - Very harmful tumourPlace of development: It develops in the cells that give the skin its color (melanocytes)Development: On normal skin or allready existing cellular nevus (mole, birthmark)Starting point: Basal cells;At first it usually grows in a horizontal direction being rather superficial but depending on the type of melanoma it may start growing rapidly in a vertical direction at an early stage.
10 Ca. 20% of all melanomata belong to the so called nodular melanoma (NM). The NM varies in colour from blue to dark brown. Melanoma is so dangerous, because once it grows to a certain thickness, it metastasizes or spreads throughout the body. After melanoma has spread to the internal organs there is little that can be done and death follows shortly after.
11 The superficial spreading melanoma (SSM) accounts for about 60% of all melanomata and is the most common type. SSM undergoes two growth phases. During the "radial" phase, the lesion expands through the epidermis (upper skin layer). In the early radial phase, which may last months or years, the lesion is thin. After the radial phase, a "vertical" growth phase begins. It may contain areas of tan, brown/black, red, dark blue/purple, or white coloration. This melanoma often appears as a flat „spot“ with regular borders.
14 Do we all react alike?Because of the advancing loss of Ozone within the stratosphere, the intensity of the UV-radiation increased noticeably. The sensitivity towards UV-A-radiation depends on the skin type.We all react alike towards UV-B and UV-C, because those rays were not planned to reach the earth at all.
15 The 4 different skin types Skin: Strikingly fair, paleHair: Fair blonde to reddishEyes: Green, blueReaction to sun: Always, severe, painfulTan: No tanSunburn after: 10 min.Skin type 2Skin: FairHair: Blond to brownEyes: Grey, blue, greenReaction to sun: Mostly, severeTan : Moderate tanSunburn after: 15 min.
16 The 4 different skin types Skin: Light tan, olive Hair: Deep blonde, brown Eyes: Grey, brown Reaction to sun: Rarely, moderatelyTan: Good tan Sunburn after: min.Skin type 4Skin: Brown Hair: Deep brown, blackEyes: BrownReaction to sun: Hardly anyTan : Fast and deep; very good tanSunburn after: min.
17 Examples for other illnesses Damage to the eyesGeneral weakening of the immune system
18 Effects on natureA permanent damage to the environment leaves broad features on plants:Retrenchment of the photosynthesisShorter sproutsDecrease of the average leaf surfaceAlterations within the plant communitiesThese alterations could lead to extensive crop loss and to changes within the food chain or could contribute to forest dieback.
19 Effects on nature The nutrient-rich phytoplankton (e.g. Algaes) decline in the seas. As the process develops the followingtendencies become apparent:Lack of food for fish and changes in thecomposition of speciesLoss of the greatest producer of oxygen, as well as lessconversion of CO2Increase of the greenhouse effect
20 Situation and structure The Ozone LayerSituation and structure
21 General information about the Ozone layer The Ozone layer is located in the stratosphere.The highest concentration of Ozone exists at a height from 20 to 25km and serves as a shield against UV-B and UV-C radiation.This is the only way life on earth, as we know it today, is possible.
22 Structure of the Atmosphere Our habitat is situated in the Troposphere
24 Why above the Antarctic? The graph to the right shows the measured total ozone above the Halley Bay station in Antarctica.
25 Why above the Antarctic? Owing to temperatures of - 80° C water vapour condensates in the stratosphere. PSCs form and are made of ice, nitric acid and sulphuric acids.(PSC = Polar Stratospheric Clouds).The HCl and ClONO2 molecules are able to react with the ice crystals of the PSCs.HCl is tied to the surface of the ice crystals and reacts with the ClONO2 molecule. Thereupon, molecular Chlorine (Cl2) is released.
26 Why above the Antarctic? The descent of the cooling airmasses causes a cyclical, circumpolar votex. It encloses the cool air above the poles and prevents the warmer, more ozoniferous airmasses from reaching the lower latitudes.
27 The Future of the Ozonehole Due to the long lifespan of CFC it will take approximately 50 years before the already released CFCs in the stratosphere are removed.Furthermore, the use of CFC did not completely stop in spite of agreements such as the Montreal Protocol and succeeding protocols.
28 CFC CFC – Where are they found? Climate friendly alternatives and their disadvantages
29 CFC is an abbreviation for Chlorofluorocarbons. What are CFC‘s?CFC is an abbreviation for Chlorofluorocarbons.They were used in fire extinguishers, aerosol sprays and refrigerators.They can exist in the environment for years, as they are generally non-reactive.
30 Why does CFC destroy the ozone? UV-radiation breaks off the chlorine atom of the CFC.The chlorine atoms and Ozone react. Ozone is destroyedAt the same time Chloroxide develops and reacts with the Ozone.Ozone is destroyed, and the chlorine atoms are released again.This continuous chain reaction destroys the Ozone.
31 Climate friendly alternatives Refrigerants (since the 30s) have been replaced by the following:Since January 1st, CFC is no longer used in car air conditioners and refrigerators.Instead of CFC, Isobutane is used in today‘s refrigerators.Ammonia and Propane are used in commercial new construction.Also used, is H-FC, which is harmless to the Ozone.
32 Prohibited in foam plastics, pentane or cabondioxide are used instead. Prohibited in insulation since 1994 , glas-/ rock wool, animal or herbal fibres are used instead.Prohibited since 1992 in detergents and solvents, water-based detergents are increasingly used.Prohibitied in fire extinguishers since 1994 , carbon dioxide , water, foam and powder are used instead.Prohibited early in aerosol sprays, they are still used in special applications (antiasthmatic sprays).
33 Further climate friendly alternatives and their disadvantages Hydrocarbons (propane, isobutane, pentane) flammableCarbon dioxide harmful to the environment and climate: greenhouse effect.Water some substances lose their attributes by reacting with water.Ammonia could transform into ammonium compound, that could lead to an eutrophication of bodies of water and vegetation. Additionally, ammonia is very toxic.