TL: OUR RADIANT PLANET (SUMMARY) SO: GRENPEACE INTERNATIONAL DT: 1996 THE DANGERS OF UV-B RADIATION FOR HUMAN HEALTH AND THE GLOBAL BIOSPHERE A summary of the major themes contained in a longer, more detailed Greenpeace report by the same title. 1. INTRODUCTION 1.1 Current State Of The Ozone Layer 2. KEEPING OUR HEADS IN THE SAND : A CASE OF MISPLACED PRIORITIES 3. LIVING WITH THE DANGERS OF UV-B RADIATION Sample Public Awareness Bulletin 4. FROGS DON'T WEAR SUN GLASSES 5. UV-B IMPACTS UPON HUMAN HEALTH 5.1 Our Endangered Eyes 5.2 Our Endangered Skin 5.3 Our Endangered Lives 6. UV-B IMPACTS ON HUMAN WELFARE 6.1 Threat To The Global Pantry 6.2 Cooking The Air We Breathe 6.3 UV-B Fueling The Greenhouse Effect 6.4 The Crumbling Material World 7. IMPACT OF UV-B ON PLANTS AND ANIMALS 8. CONCLUSION "There are two axioms in ecology. The first says that everything is interconnected. If you change one factor, all others are affected. The second says that organisms in the environment have evolved complex interactions over millennia. If you alter just one, the whole thing could collapse. - Dr. Alan Teramura, University of Hawaii (Manoa) 1. INTRODUCTION The Earth is bathed constantly in a spectrum of radiant energy from the sun, energy which is essential to support all life. A small proportion of this spectrum is composed of short- wavelength, high-energy radiation including ultraviolet light. Much of this is filtered out, through absorption in the atmosphere or reflection from clouds, and life on the planet had evolved to avoid or tolerate the small quantities which naturally reach the Earth's surface. The ozone layer, located in the stratosphere, is comprised of a blanket of ozone molecules. It is the primary protective shield that life on Earth has against the deadly ultraviolet rays of the sun. During the past sixty years the ozone layer has been severely damaged by millions of tonnes of ozone depleting substances (ODSs), most notably chlorofluorocarbons (CFCs), released to the atmosphere by humans. Other ODSs include hydrochlorofluorocarbons (HCFCs), methyl bromide (MeBr, halons and other industrial compounds which contain chlorine and bromine. This chemical warfare against the ozone layer continues to this day. ODSs are very stable and can survive in the atmosphere for many years or decades. They are carried up to the stratosphere by air currents where eventually they disintegrate under UV light. Their disintegration releases their chlorine or bromine molecules, which creates a chemical chain reaction leading to the large scale destruction of ozone molecules. It is estimated that one chlorine molecule can destroy up to 100,000 ozone molecules before it is neutralized. The ozone layer is a key element for a healthy, productive planet rather than a scorched, barren one. A decrease in the number of ozone molecules in the stratosphere reduces the atmosphere's ability to absorb UV-B radiation before it reaches the surface of the Earth. Changes of only a few percent in the thickness of the atmospheric ozone layer allow significant increases in the amount of UV-B radiation that filters through, and can have a profound impact upon all life. This added UV-B radiation impacts on the stability of the global ecosystem; on the genetic health of all life; on the quality of the air and nature of the weather and climate; and on human health and welfare. Depletion of ozone through man's activities has already raised the amount of UV-B reaching large areas of the Earth's surface to levels capable of widespread damage to life. There is now such a reservoir of ozone depleting chemicals in the atmosphere that, even if further emissions ceased today, current trends of ozone destruction are set to continue for several decades. Unless emissions are stopped immediately, ozone depletion and damage to the global biosphere could become very severe and even irreversible. We could already be on the edge of a spiral towards the breakdown of the biosphere as we know it. We live on a radiantly beautiful planet. It is our responsibility, for the sake of all future generations of life, to ensure that we don't leave behind us a radiantly scorched Earth that can no longer sustain life. 1.1 CURRENT STATE OF THE OZONE LAYER Each year the ozone layer is more damaged than in previous years, and the ozone crisis is rapidly escalating. In March 1995, for example, scientists reported an alarming thinning of the ozone layer over the Arctic, Siberia and Scandinavia. In some altitudes ozone levels were 50 per cent below those previously observed. On average, a 20-30 per cent reduction in Arctic ozone levels was reported. The British newspaper, The Guardian, headlined its front page story, "First Ozone Hole Found Over Arctic". Between November (1994) and February (1995) there was an average ozone loss of 10-12 per cent, over Europe, and 5-10 per cent in North America.  Du reached as high as 20 per cent over both continents. On September 12, 1995, the World Meteorological Organization reported that ozone depletions over the Antarctic was "so far the most rapid depletion on record" with severe ozone depletions covering "about 10 million square kilometers (about the size of Europe)". This was double the size of the Antarctic ozone hole during the same period in 1993 and 1994, which until 1995 had the "lowest ozone values ever observed by scientists". 2. KEEPING OUR HEADS IN THE SAND : A CASE OF MISPLACED PRIORITIES The ozone layer's most vulnerable period is expected around 1998-2000 when the accumulated atmospheric chlorine/bromine levels from human made chemicals will be at their peak. At that time ozone depletions are expected to be the most severe and UV- B radiation at the highest. This expectation may or may not be realized, and largely depends on the adequacy of the controls on the production of ODSs under the terms of the Montreal Protocol and its amendments and whether or not all the countries adhere to the full regime of those controls. Furthermore, it depends on the accuracy of scientific projections, which until now have consistently underestimated expected levels of ozone depletion. There is certainly room for some more nasty surprises. The thinning of the ozone layer allows more ultraviolet-B radiation to reach the surface of the earth. Higher levels of UV-B radiation dramatically increase the risk of severe damage to human health (e.g. eye diseases, skin cancer, immune system suppression) and also endanger crops, forests, plants, marine life and wildlife. Although there are natural variations in UV-B levels reaching the earth, and there is some conflicting data regarding UV-B measurements, several studies suggest that the global increase in UV-B incidence may be quite severe. For example, a 35 per cent increase was recorded between 1977/78 and 1986 at a station in Maryland, USA, a 35 per cent increase in winter levels between 1989 and 1993 in Toronto and an estimated 30 per cent increase in Tokyo over the period from 1980 to 1991. Measurements in Antarctica in 1993, a year of particularly severe ozone depletion, were over 50 per cent higher than in 1991 and 1992. Though we are entering this most vulnerable period of heightened UV-B bombardment exploding upon the global ecosystem, scientific research into the impact of increased UV-B radiation upon the biosphere is tragically underfunded. It is almost as if we don't really want to know, or we don't really care about what the future may bring. The UNEP affiliated Scientific Committee On Problems of the Environment (SCOPE) forewords its 1993 report "Effects of Increased Ultraviolet Radiation on Global Ecosystems" with the following forthright admonition: "The fact that the number of experts on the effects of increased UV-B impacts on living systems due to ozone depletion continues to be rather small, illustrates that for the past 20 years, the governments of the world seemed not to take seriously this potential threat to the biosphere. Candidly stated, research funding for "effects" research has been paltry at best." If doctors told us that a loved one has a potentially fatal disease, we would most likely want to learn as much as there is to know about the disease and possible cures. Shouldn't we apply the same resolve to informing ourselves about the dangers we have brought upon Earth, so that we could do whatever is in our power to minimize the damage? Shouldn't learning about the future of life, under a regime of increased UV-B radiation, be of higher priority than, for example, the development of yet another intercontinental ballistic missile system, or a new generation of nuclear weapons? And yet the funds committed to UV-B research are minuscule in comparison to funds spent on weapons of mass destruction. IMPACTS OF ULTRAVIOLET-B RADIATION UPON THE BIOSPHERE, HUMANS AND HUMAN WELFARE The impacts of UV-B-induced damage spread across the Earth from the polar seas to the alpine meadows, from the smallest bacteria to the great whales, from the human food supply to the incidence of skin cancers and blindness. Measurements of the ozone layer have shown a continued thinning trend over the last decade. Evidence of biosphere damage continues to grow suggesting the problems are widening and deepening every day. * Impacts on life processes from mutations of genetic material in DNA to the productivity of plants; * Impacts on marine aquatic ecosystems from damage to phytoplankton at the bottom rung of the global food chain to the survival of the great whales; * impacts on freshwater aquatic ecosystems from the reduction of algae to the death of frog eggs and fish fry; * impacts on terrestrial ecosystems from the health of trees to the stability of the great forests; * impacts on human health from sunburn to skin cancer; from immune suppression to blindness; * impacts on human welfare from the fear of diseases to the stability of food supplies; from the costs of health care services to the health of indigenous peoples; * impacts on environmental chemistry from increases in photochemical smog to decreases in water quality; * impacts on materials from human-made plastics to natural woods and fibres; * impacts on biogeochemical cycles from the carbon cycle which affects the global climate to the sulphur and nitrogen cycles which sustain life; * impacts on weather and climate from local rains to global warming. 2. KEEPING OUR HEADS IN THE SAND : A CASE OF MISPLACED PRIORITIES The ozone layer's most vulnerable period is expected around 1998-2000 when the accumulated atmospheric chlorine/bromine levels from human made chemicals will be at their peak. At that time ozone depletions are expected to be the most severe and UV-B radiation at the highest. This expectation may or may not be realized, and largely depends on the adequacy of the controls on the production of ODSs under the terms of the Montreal Protocol and its amendments and whether or not all the countries adhere to the full regime of those controls. Furthermore, it depends on the accuracy of scientific projections, which until now have consistently underestimated expected levels of ozone depletion. There is certainly room for some more nasty surprises. The thinning of the ozone layer allows more ultraviolet-B radiation to reach the surface of the earth. Higher levels of UV-B radiation dramatically increase the risk of severe damage to human health (e.g. eye diseases, skin cancer, immune system suppression) and also endanger crops, forests, plants, marine life and wildlife. Although there are natural variations in UV-B levels reaching the earth, and there is some conflicting data regarding UV-B measurements, several studies suggest that the global increase in UV-B incidence may be quite severe. For example, a 35 per cent increase was recorded between 1977/78 and 1986 at a station in Maryland, USA, a 35 per cent increase in winter levels between 1989 and 1993 in Toronto and an estimated 30 per cent increase in Tokyo over the period from 1980 to 1991. Measurements in Antarctica in 1993, a year of particularly severe ozone depletion, were over 50 per cent higher than in 1991 and 1992. Though we are entering this most vulnerable period of heightened UV-B bombardment exploding upon the global ecosystem, scientific research into the impact of increased UV-B radiation upon the biosphere is tragically underfunded. It is almost as if we don't really want to know, or we don't really care about what the future may bring. The UNEP affiliated Scientific Committee On Problems of the Environment (SCOPE) forewords its 1993 report "Effects of Increased Ultraviolet Radiation on Global Ecosystems" with the following forthright admonition: "The fact that the number of experts on the effects of increased UV-B impacts on living systems due to ozone depletion continues to be rather small, illustrates that for the past 20 years, the governments of the world seemed not to take seriously this potential threat to the biosphere. Candidly stated, research funding for "effects" research has been paltry at best." If doctors told us that a loved one has a potentially fatal disease, we would most likely want to learn as much as there is to know about the disease and possible cures. Shouldn't we apply the same resolve to informing ourselves about the dangers we have brought upon Earth, so that we could do whatever is in our power to minimize the damage? Shouldn't learning about the future of life, under a regime of increased UV-B radiation, be of higher priority than, for example, the development of yet another intercontinental ballistic missile system, or a new generation of nuclear weapons? And yet the funds committed to UV-B research are minuscule in comparison to funds spent on weapons of mass destruction. IMPACTS OF ULTRAVIOLET-B RADIATION UPON THE BIOSPHERE, HUMANS AND HUMAN WELFARE The impacts of UV-B-induced damage spread across the Earth from the polar seas to the alpine meadows, from the smallest bacteria to the great whales, from the human food supply to the incidence of skin cancers and blindness. Measurements of the ozone layer have shown a continued thinning trend over the last decade. Evidence of biosphere damage continues to grow suggesting the problems are widening and deepening every day. * Impacts on life processes from mutations of genetic material in DNA to the productivity of plants; * Impacts on marine aquatic ecosystems from damage to phytoplankton at the bottom rung of the global food chain to the survival of the great whales; * Impacts on freshwater aquatic ecosystems from the reduction of algae to the death of frog eggs and fish fry; * Impacts on terrestrial ecosystems from the health of trees to the stability of the great forests; * Impacts on human health from sunburn to skin cancer; from immune suppression to blindness; * Impacts on human welfare from the fear of diseases to the stability of food supplies; from the costs of health care services to the health of indigenous peoples; * Impacts on environmental chemistry from increases in photochemical smog to decreases in water quality; * Impacts on materials from human-made plastics to natural woods and fibres; * Impacts on biogeochemical cycles from the carbon cycle which affects the global climate to the sulphur and nitrogen cycles which sustain life; * Impacts on weather and climate from local rains to global warming. 3. LIVING WITH THE DANGERS OF UV-B RADIATION "What does it mean to redefine one's relationship to the sky? What will it do to our children's outlook on life if we have to teach them to be afraid to look up?" -US Vice -President Al Gore Concern over the impacts of increased ultraviolet radiation exposure on human health has caused governments around the world to established daily warning programs. For example, in Australia, Austria, Canada, Germany, Great Britain, New Zealand, Netherlands, and the United States, forecasts for the level of solar ultraviolet radiation and sunburn times are disseminated through newspaper, radio and television messages. The Dutch authorities conduct an annual skin cancer awareness campaign, including the provision of free sun-screen to people working outdoors. Canada's UV Index is a forecast of the time required for fair, unprotected skin to burn under the highest sun based on the thickness of the ozone layer above and the time of year. It is provided to the news media daily. In many newspapers, it is front page information. The commercial television weather service, The Weather Network, provides a feature on the Index and actual UV measurements twice hourly during most of the year. Messages such as Australia's "Slip, Slap, Slop" campaign urge citizens to slip on a shirt, slap on a hat and slop on sunscreen for protection. Public information campaigns by governments and public health organizations provide added information on the hazards of sun exposure. Alterations of school programs and other outdoor activities are aimed at reducing sun exposure for children. Teams of doctors specializing in skin cancers are roaming public beaches to educate sunbathers as to the dangers of excessive sun. General advice is for people to avoid exposure to direct sunlight between 11 AM and 4 PM. While programs to educate and alert the public are absolutely necessary, they are also at additional costs to public treasuries and in most countries draw upon already scarce resources. Some countries, especially developing nations, simply don't have the resources to protect the public through high profile public information campaigns. While everyone's life will, one way or another, be negatively affected by the impacts of increased UV-B radiation, poorer countries will suffer to an even greater extent. A SAMPLE OF A PUBLIC AWARENESS BULLETIN POSTED AT A COMMUNITY CENTRE IN VANCOUVER, BRITISH COLUMBIA, CANADA, UNDER THE HEADING SUN SAFETY. DID YOU KNOW ? * The sun's rays can cause sunburn, wrinkles and skin cancer * 1 bad sunburn during childhood can double a child's risk of developing skin cancer in later life * the depletion of the ozone layer above Canada in the last ten years has resulted in an increase in skin cancers by 13 per cent; this increase will continue throughout the 1990's * 50,000 Canadians will get skin cancer this year, 500 will die from it. * most skin cancers can be cured if treated at an early stage * almost all skin cancers are curable - SUN SENSITIVITY TEST - Your risk of skin cancer is related to your skin type and the amount of time you spend in the sun. How vulnerable are you ? Answer Yes or No to the following statements: * I have red or blond hair. * I have light-colored eyes, blue green or gray. * I always burn before I tan. * I freckle easily. * I have many moles. * I had two or more blistering sunburns before I turned 18. * I lived or had long vacations in a tropical climate as a child. * There is a family history of skin cancer. * I work outdoors. * I spend a lot of time in outdoor activities. * I am an indoor worker but like to get out in the sun as much as possible when I am able. * SCORE YOURSELF 10 points for each "yes". * ADD an additional 10 points if you use tanning devices, tanning booths or sun lamps. (80-100) You are in the high risk zone. Read on to find out how you can protect your skin from the sun. Examine your lifestyle to see what changes you can make. (40-70) You are at increased risk. Pick up the following tips on sun protection and take all precautions possible. (10-30) You're still at risk. Carry on being careful. - SUN SAFETY HINTS - 1.Limit your time in the sun. Try to stay out of the sun between 11 AM and 4 PM. FOR CHILDREN: Play inside, go to the library, visit with friends inside, do arts and crafts in the kitchen, sleep. 2.Protect yourself. Wear a hat, clothes, sunscreen with and SPF of at least 15. 3.Check your skin every month. SPOT CHECK your skin from your head to between your toes once a month. The following ABCD's may be signs of malignant melanoma. A. Asymmetry - one half unlike the other half B. Border irregularity - scalloped or poorly circumscribed border C. Color varied from one area to another; shades of tan and brown; black; sometimes white, red or blue. D. Diameter larger than 6 mm (diameter of a pencil eraser). 4.Beware of tanning beds and pills. Many are untested and unsafe. 5.Wear sunglasses. Make sure they properly block UV radiation. Sunglasses that only partially block UV may actually hurt your eyes more than not wearing sunglasses at all. 4. FROGS DON'T WEAR SUN GLASSES Warnings and education campaigns for sun avoidance are okay for humans, but what about the frogs laying their eggs in high mountain ponds and streams as they have for millennia, or the phytoplankton in the seas seeking the sun to run their photosynthetic production, or the trees rooted in the earth and stretching their leaves or needles skyward to the sun? They cannot avoid the noonday sun, or slip on a shirt or hat, or use sunscreen, or be brought indoors. They must be protected from further exposure to UV-B radiation. This can only be accomplished through a concerted human effort to eliminate the release of those chemicals which destroy the ozone layer. UV-B IMPACTS ON HUMAN HEALTH AND WELFARE Increases in UV-B Radiation: * Initiate and promote malignant and non-malignant skin cancers; * Suppress the immune system to various bacteria and viruses; * Cause eye damage including cataracts; * Enhance severity of sunburn and skin aging; * Increase the risk of allergic and toxic dermatitis; * Activate certain disease bacteria and viruses; * Increase cost of health care; * Impact prominently on indigenous populations; * Reduce yield in many significant food crops; * Reduce fisheries yield. * Destroy outdoor equipment and materials 5. UV-B IMPACTS UPON HUMAN HEALTH 5.1 OUR ENDANGERED EYES Blindness from cataracts is the major preventable cause of blindness in the world today. Chronic UV-B exposure has been shown to be a factor in this eye disease. Latest findings indicate that each 1 per cent decrease in ozone levels results in 0.6 per cent to 0.8 per cent increase in eye cataracts, or annually approximately 100,000 to 150,000 additional cases of cataract-induced blindness worldwide. In tropical areas where UV-B radiation is highest, cataracts are striking at a younger age than ever before. Young children are particularly sensitive because of the less-developed pigmentation of the eye. UV-B causes other eye injuries including photokeratitis also known as 'sun blindness' or 'snow blindness', damage to the retina, and intraocular melanoma tumors. Predictions suggest a substantial future increase in eye cancer rate in lower latitudes. Exposure of the lens and retina to UV-radiation may be enhanced by wearing sunglasses which absorb UV poorly; as the iris opens wider to compensate for reduced visible light, so the penetration of UV also increases. 5.2 OUR ENDANGERED SKIN We continue to live under the misguided belief that a tanned body is a healthy body. As a result, incidents of malignant and non-malignant skin cancers are growing world-wide at epidemic proportions. The rate is expected to increase dramatically in the future as ozone depletion permits more UV-B rays to reach the ground. There is compelling evidence that solar ultraviolet radiation is a complete carcinogen, acting on all major stages of cancer: its initiation, its promotion and its progression. Children are particularly at risk. A severe sun burn in childhood dramatically increases an individual's chances of developing some form of skin cancer later in life. Even at current UV-B exposures, certain forms of skin cancer affect 1 in 5 people in the United States and as many as 2 in 3 people in Australia. Such cancers are becoming increasingly common in younger people. Between 1979 and 1993, the incidence of non-melanoma, the most common form of skin cancer, is estimated to have risen an average of 10 per cent in the Northern Hemisphere, between the latitudes 55 degrees N and 35 degrees N. Even bigger increases are believed to have occurred in the Southern Hemisphere. UNEP forecasts that a sustained 1 per cent decrease in stratospheric ozone will result in a 2 per cent increase of this type of skin cancer. On the basis of an estimated 10 per cent reduction in ozone, a 25 per cent increase in non-melanoma skin cancer rates has been predicted for temperate latitudes by 2050. Less common, but much more dangerous, are malignant melanomas which effect the pigment cells in the skin and which can spread rapidly to the blood and lymphatic system. These have become increasingly frequent throughout the world over the last 40 years and, although detection and recovery rates have improved, they already represent the most common cause of cancer-related deaths in Australian adults under 45 years of age. Between the periods 1978-82 and 1983-87, for example, melanoma incidence increased in most European and Scandinavian countries, with increases from around 9 per cent in the Netherlands too as much as 56 per cent in Scotland. Mortality rates have also increased rapidly, by up to 4 times in both Canada and in the Netherlands between 1950 and 1990. In 1991 the US Environmental Protection Agency projected that over the next fifty years 12 million Americans will contract skin cancer and 200,000 will die from malignant melanoma. In 1994, UNEP once again confirmed that increases in UV-B radiation are likely to increase "the incidence and morbidity from skin cancer" and that "epidemiological data indicate that the risk of melanoma increases with sunlight exposure, especially during childhood." 5.3 OUR ENDANGERED LIVES The burning goes deeper, however than sunburn, skin cancers and cataracts. UV-B radiation also has the ability to suppress the human immune system leaving the body vulnerable to many diseases caused by bacteria and viruses entering through or affecting the skin. UV-B may even play a role in the course of non-skin cancers through its suppression of the immune system which weakens the body's defense against the early stages of tumor formation. While darker skinned individuals are less likely to contract a skin cancer from sun exposure, dark skin is not a protection against immune suppression by UV-B. Dark skin requires a greater dosage of UV-B than white skin to initiate immune suppression. However, the required dosage for suppression in darker skins is easily obtained by occupational and recreational exposure to the sun. Viruses responsible for diseases such as herpes, chicken pox, the human immunodeficiency virus HIV- 1 and a variety of papilloma viruses are directly activated or reactivated by exposure to UV-B radiation. Increased exposure to UV-B radiation in animals and humans has been linked to elevated risk from the following diseases: those caused by the herpes viruses, leishmaniasis, malaria, forms of tuberculosis and leprosy, lupus erthematodes, contact dermatitis and toxic photo dermatitis, and a number of bacterial and fungal infections including E. coli and Staphylococcus aureus. Exposure may also affect vaccinations against diseases. Impairment of the immune system by UV-B may prevent the desired response to the vaccine. UV-B readily damages DNA. Thus, it is not unrealistic to hypothesize that UV-B radiation will play an additional role in the mutation of existing disease bacteria and viruses and may produce totally new strains of pathogens. Humanity is just waking up to the fact that in coming years we shall be facing an onslaught of new and resurgent diseases, such as malaria, cholera and dengue fever as a result of global warming and climate change. UV-B induced immunosuppression will make humans that much more vulnerable under very precarious circumstances. It is not possible to estimate in monetary terms how much UV-B induced health problems are already costing society. Nevertheless, based on realistic scenarios regarding the present and future impacts of increased UV-B upon human health, it is safe to predict that those costs will continue to grow at a phenomenal rate. "[In] areas of the world where infectious diseases already pose a significant challenge to human health and in persons with impaired immune function, the added impact of UV-B induced immune suppression could be significant." - United Nations Environmental Programme "Infection and disease is a greater global challenge than cancer, as people of all skin pigmentation are at equal risk from the effects of immunosuppression. Geographic areas of poor public health are at even greater risk." - Dr. Margaret Kripke, University of Texas 6. UV B IMPACTS ON HUMAN WELFARE Increased levels of UV-B can have wide-ranging impacts on other aspects of human welfare such as disruptions to our food supply; further deterioration of the quality of the air, water and soils upon which we are dependent; further contribution to the greenhouse effect, and resultant climate change; and deterioration of plastics and other materials widely used by society. 6.1 THREAT TO THE GLOBAL PANTRY In addition to the direct effects of UV-B radiation on human health, increases in UV-B radiation will have important indirect impacts on human health through alterations of the food supply. Many agricultural crops including varieties of important food staples such as rice have been shown to be adversely affected by increases in UV-B radiation. Such impacts may be manifest as losses in yield, higher susceptibility to damage from temperature, drought and disease, changes in reproductive cycles, and alterations of nutritional composition. With the human food supply already strained due to demands of an ever increasing population, changes in weather and climate and loss of soil fertility, even small reductions resulting from UV- B damage to the food supply may be disastrous to many people, especially the poor and indigenous people. Reduction in crop yield or livestock viability could present severe problems for food supply, particularly in areas relying on subsistence agriculture or in economies in which food supply is already under strain. Indigenous populations are especially at risk from increases in UV-B radiation since they generally rely on local plants and animals as their food source. Once local food supplies are compromised, they don't have the commercial infrastructures in place to supplement their diet with imported food. Furthermore, lack of nearby medical care and facilities may magnify the direct health effects of increases in UV-B radiation. Fisheries are also in peril from increases in UV-B radiation through disruption of the aquatic food chain or the direct killing of eggs and larvae of commercially valuable species. It is estimated that 16 per cent ozone depletion could result in 5 per cent loss in phytoplankton (the basis of all food in the seas), which would lead to a loss of about 7 million tons of fish per year - about 7 per cent of fishery yield. Under the Antarctic ozone hole productivity from phytoplankton was down by 6-12 per cent. UV-B radiation also damages the developmental stages of fish, most notably anchovy, where near 100 per cent mortality could occur with 16 per cent ozone depletion. UV-B IMPACTS ON AQUATIC ECOSYSTEMS Increases in UV-B Radiation: * Reduce the production of phytoplankton, the base of the aquatic food chain; * Impair the ability of plankton to respond to solar radiation; * Disrupt the food chain through reductions in predator and prey populations; * Alter species distributions within freshwater and marine communities; * Damage eggs and kills larvae of species which use shallow water in their early life cycle; * Affect water quality through photochemical reactions. 6.2 COOKING THE AIR WE BREATHE With depletion of the ozone layer, solar UV-B radiation passes deeper into the atmosphere, closer to earth. Here it encounters a variety of chemicals emitted by human activities into a chemical mixture that is thickest around the major cities of the world. In the lower atmosphere, UV-B is a catalyst in the production of some very reactive chemicals (such as hydroxyl, hydrogen peroxide and ozone). These compounds help the solar UV radiation to cook the mixture of chemical ingredients into a photochemical soup hazardous to human health, plants and materials. Included in this soup are a variety of acidic compounds formed from human emissions of sulphur and nitrogen oxides which eventually fall to earth as acid deposition or acid precipitation and alter soil, freshwater and plant life. This soup, known as photochemical smog, has reached unhealthy proportions in cities around the world: Los Angeles, Denver, Chicago, New York, Mexico City, Manila, Vancouver, Toronto, Berlin, Taipei and Tokyo. Drifting ozone smog also endangers areas outside of large population centres, where due to the absence of other neutralizing pollutants in the air, ozone levels tend to be higher and last longer than over cities. Photochemical contains chemical compounds hazardous to human health, causing and enhancing respiratory diseases and increasing the risk of respiratory or heart failure. Its constituents are hazardous to plant life including agricultural varieties. Acidic components such as sulphuric acid and strong oxidizers such as ozone reduce the useful lifetime of materials including plastics, metals, and limestone. 6.3 UV-B FUELING THE GREENHOUSE EFFECT Air pollutants produced by UV-B radiation, acting in concert with the direct effects of UV-B on life, alter the flow of elements through the atmosphere, the hydrosphere, the lithosphere and the biosphere. Most important of these are the flows of carbon, sulphur and nitrogen. Changes in these affect global and local biogeochemical cycles and atmospheric processes such as rainfall and cloud formation. For example, changes in the flow of sulphur and nitrogen may reduce the availability of nutrients important to plants. Without these nutrients, plants' ability to produce biomass which stores carbon is reduced. This carbon comes from carbon dioxide in the atmosphere. A 10 per cent decrease in phytoplankton productivity, for example, will prevent 5 gigatonnes of carbon dioxide from being absorbed from the atmosphere ; this will increase the greenhouse effect further. Decreasing the amount of carbon removed from the atmosphere and stored in the biosphere will further increase the carbon dioxide levels in the atmosphere already rising rapidly due to the burning of fossil fuels. This will cause a rise in atmospheric temperature, the so-called "greenhouse effect." UV-B IMPACTS ON AIR, WATER AND SOIL QUALITY Increases in UV-B radiation: * Produce or alter toxic air and water pollutants; * Increase photochemical smog in rural and urban regions; * Alter atmospheric chemistry resulting in a buildup of air pollutants; * Increase the transformation of acid compounds which cause acidification of soils and waters; * Modify chemical compounds involved in important biogeochemical cycles; * Influence climate and weather. * Have a positive feedback influence on global warming. As US Vice President Al Gore explains the relationship between ozone depletion, increased UV-B radiation and global warming in his book, Earth In Balance: "...the two best-known crises, global warming and stratospheric ozone depletion, reinforce each other in a complex positive feedback loop. Global warming increases the amount of water vapor throughout the atmosphere and traps infrared heat in the lower part of the sky which would otherwise radiate back out to space, passing through the atmosphere. As a result, the stratosphere actually cools as the lower atmosphere warms. A cooler stratosphere with more water vapor means more ice crystals in the ozone layer, especially in the polar regions, where chlorofluorocarbons (CFCs) mingle with the ozone in the presence of the ice, thus depleting the ozone at a faster rate. The thinner the ozone layer, the more the ultraviolet radiation strikes the surface of the earth and all organisms living there. The ultraviolet radiation strikes vegetation that normally absorbs vast quantities of CO2 through photosynthesis and seems to seriously disrupt its ability to do so. As the vegetation absorbs less CO2, more of it accumulates in the atmosphere, causing still more global warming - and still more stratospheric cooling. The cycle is reinforced and magnified. It feeds upon itself." Thus, elevated UV-B radiation will have indirect influences on the weather. If these impacts continue over the long term, change in global and local climate will occur. Increasing global or regional temperatures will further impact the biosphere which further alters the carbon cycle. And so the cycle continues. 6.4 THE CRUMBLING MATERIAL WORLD Enhanced UV-B also has the potential to impact on other aspects of modern human life. Exposure to UV-radiation is the primary cause of degradation of non-metallic material outdoors; rubbers (natural and synthetic) and plastics are particularly vulnerable. Effects include discoloration, cracking and overall weakening of material. Increases in incident UV- B will, therefore, have consequences for the building industry, the transport manufacturing and maintenance industries and a wide range of other materials sectors. The unaccounted global damage from UV-B acting upon materials may well be in the hundreds of millions of dollars on a yearly basis. 7. IMPACT OF UV-B ON PLANTS AND ANIMALS UV-radiation has long been known to be damaging to life; indeed this quality is being employed increasingly for the disinfection of water and for the mutation of microorganisms for laboratory experiments . UV-B affects plants and animals by modifying both their biological and chemical environment. Damage may occur in a number of ways, including the direct destruction of the genetic material DNA, deactivation of enzymes, disruption of membranes and other cell structures and the generation of highly reactive chemical agents known as "free radicals". Although biological repair mechanisms exist, mutations may remain as errors in the repair processes. In addition, the repair mechanisms themselves may be deactivated by high UV doses. The interaction of all these processes can lead to a variety of adverse effects on plants and animals. Many effects are sub-lethal, may interact with other factors and may, therefore, be very difficult to attribute to UV-enhancement specifically. Effects on plants in the sea, in freshwater and on land are of fundamental importance because of their position at the base of all other food chains. By nature, plants have evolved to maximize the surface area they expose to sunlight, but consequently their exposure to damaging UV-radiation is also increased. Elevated UV exposure can cause temporary or irreversible damage to photosynthetic apparatus (including the bleaching of the pigments which trap the sun's energy), to processes of cell division and growth regulation, and to the composition and replication of genetic material. Consequences include a reduction in growth yield, changes in levels and effects of plant hormones and alteration of periods of dormancy, flowering, etc. UV-B IMPACTS ON TERRESTRIAL ECOSYSTEMS Increases in UV-B radiation: * Alter soil quality and the soil ecosystem; * Decompose soil litter; * Influence plant growth; * Influence plant life cycles including timing of flowering, leaf-drop, dormancy and death; * Alter biogeochemical cycling of carbon, nitrogen, etc.; * Affect susceptibility of plants to disease, drought, temperature and pollution; * Modify the distribution of species within an ecosystem; * Disrupt the terrestrial food chain; * Alter inter-species competition for food, light and space; * Damage eggs and larvae of terrestrial fauna. Reductions in photosynthetic rate and capacity have been described for a number of tree species; experiments have shown that as little as 16 per cent decrease in current ozone levels could result in a 40 per cent reduction in productivity in the Loblolly pine. Similar effects are reported for jackpine, spruce, sycamore, birch and ash, although effects are normally more severe in conifers than in deciduous species. The potential for worldwide woodland and forest damage is clear. Plants from alpine and high latitude environments, and those most exposed in other regions, are among the most UV-resistant species. Nevertheless, recent evidence suggests that even these species suffer reduced productivity under the already significantly enhanced levels of UV-B. In addition, adverse physiological and developmental effects may well be brought about by UV- B indirectly through alterations to the production and concentrations of plant hormones and other growth regulators. It is thought that, in many cases, UV-B simply acts as an additional stress to plants already challenged by, for example, drought, soil contamination or disease. Under such circumstances enhanced UV-exposure could tip the balance against survival. Even less is known about the impacts of UV-B radiation on land animals than is known for plants. Impacts are likely both through direct exposure of sensitive areas of the body and indirectly through effects on food species further down the food chain. Again, as for aquatic organisms, juveniles will be among the most sensitive and least protected individuals. In mature animals, the principle target of UV-damage is uncovered skin. Exposure to excessive UV-B can lead to skin burning, changes in pigmentation and in vitamin D- synthesis, with increased risks of skin cancers, eye conditions and suppression of the immune system over the longer-term. Juveniles are especially vulnerable. Damage to juveniles before their protective barriers (body hair, shells, skin pigmentation) are fully developed will likely kill the individual before it reaches maturity. Few wild animals, especially those which are prey, are able to overcome a childhood weakness. WHEN A TREE BURNS IN THE FOREST, WHO WILL SEE IT? If a tree falls in the forest, will anyone hear it? If a tree burns under the searing rays of UV-B radiation, will anyone see it? And will anyone notice the slow alteration of terrestrial ecosystems before it is too late to stop the burning from going deeper? The global depletion of the ozone layer is increasing the rain of UV-B radiation on forests from the equator to the subpolar regions. This radiation has many impacts, some of them subtle and indirect, on all forest ecosystems. Even small increases in the amount of UV-B, especially in the shorter wavelengths, will reduce the growth of many plants, change plant internal chemistry, influence plant and animal life cycles, affect the decomposition of ground litter, and even alter the air flowing through the forest. Such impacts will change the distribution of species within a particular ecosystem, and these changes will cascade to other levels of the food chain. This burning will not leave a charred stump as do the forest fires quickly raging through many of the forests today. Instead the burning will be slow, internal damage visible to the casual observer only as curled needles or subtle changes in leaf colour. The burning rays of UV-B radiation will first affect those trees most directly exposed to it: the crowns of the tallest trees, trees growing at the edges of clearings and rivers and seedlings in clear-cut zones. But they will also penetrate deeper as time goes on to the lower layers of the forest canopy until ultimately reaching the soil. There, UV-B will influence the production of the soil itself through alterations in soil chemistry and impacts on the lives of the soil biota, microbes, fungi, plants and invertebrates which transform forest litter to a nutrient-rich humus capable of sustaining many forms of life. THE LONELY DEATH OF PENGUIN CHICKS - SCIENCE FICTION OR SCIENTIFICALLY PLAUSIBLE SCENARIO? In January 1995, the mass starvation of penguin chicks in three widely separate regions of Antarctica was reported by Australian scientists. Some penguin parents were observed as far as 200 km offshore desperately searching for food for their young. The young birds fed krill, a small shrimp-like crustacean which has mysteriously disappeared in recent years in many Antarctic waters. Scientists do not believe that harvesting of the krill could account for the decline, but they are mystified as to the cause of disappearance. Should they be? Krill feed on the normally abundant crop of phytoplankton which bloom in Antarctic waters every spring. These blooms occur under the ever-growing Antarctic Ozone Hole which permits high levels of deadly UV-B rays to penetrate into the ocean water. Scientists from around the world have spent many recent years under the Antarctic Ozone Hole observing the UV-B damage to the spring phytoplankton bloom. Studies suggest that UV-B radiation kills only certain species of phytoplankton and causes others to clump together for protection. The surviving phytoplankton may thus be too large to be eaten by krill and so the krill die. The death of large quantities of krill leads to pressures on the remaining krill from predatory fish, seals, whales and birds. This could lead to a collapse of the krill communities near the penguin rookeries forcing parent birds to search far out to sea for food for themselves and their young. 8. CONCLUSION Despite the every increasing list of negative effects of UV-B radiation, we continue to release ozone-depleting chemicals into the atmosphere. Despite the availability of safer alternatives, we continue to promote technologies which are only slightly safer than the ones they replace. Despite the agreements under the Montreal Protocol, the manufacture and release of ozone- depleting substances continues. Despite the wisdom of the global scientific community showing us the need for quick action, we drag our feet. Scientific research has only begun to scratch the surface on the impacts of UV-B radiation, but what is known is cause for concern. We cannot afford to sit and wait for the damage to reach a scale that forces us to act; by then it will be too late. We must wholeheartedly embrace the Precautionary Principle which states that we must not wait for scientific certainty before acting when there is evidence of environmental damage. The time to act is now. We can no longer afford to wait for further confirmation that the signs we have already seen are definitely causing the death of ecosystems and communities. The damage is out there and growing every day. We must take heed to the impacts of ozone depletion and UV-B radiation on health, food supply, air quality and weather and climate and push for more rapid action on the elimination of ozone- depleting substances. We must put an immediate end to the production and use of all ozone- depleting substances. We must find safe but effective methods of destroying the stock-pile of these compounds before they are accidentally released into the atmosphere. Even with an immediate and complete end to production and release of ozone-depleting substances to the environment, we are left with at least a century of a below normal ozone layer and enhanced levels of UV-B radiation. How deep will the burning go? It is already deep. Deep into the seas and the forests, deep into our skin and our welfare. How much deeper? That depends on us. We must think long term and act now.