What is ozone depletion and what are the after effects>?

Answer 1

Environmental Effects of Ozone Depletion
Effects of increased ultraviolet radiation on biological systems had been investigated even before the ozone-depletion issue came to prominence. Effects such as alterations in tropospheric chemistry and potential global warming due to chlorofluorocarbons (CFCs) did not present themselves, however, until depletion and the rise in CFC levels was thought to be possible. Moan (1991) offers a brief overview of such environmental ramifications of ozone depletion in "Ozone Holes and Biological Consequences."
Several possible Ultraviolet-B Effects on Terrestrial Plants have been investigated, including reduction in yield, alteration in species competition, decrease in photosynthetic activity, susceptibility to disease, and changes in plant structure and pigmentation. Studies carried out on loblolly pine indicate retardation of growth and photosynthesis resulting from enhanced levels of ultraviolet-B (UV-B). Similar effects, including yield reduction, were found in certain rice cultivars. In field study experiments, soybean harvests showed decreases under a simulated 25 percent ozone reduction. Existing microclimatic conditions, such as drought and mineral deficiency, can reduce sensitivity to UV-B, however.

Most field studies of Ultraviolet-B Effects on Aquatic Ecosystems have taken place in the Antarctic region, due to the presence of the ozone hole during the polar springtime, and have focused on the effects on phytoplankton, the primary producers at the base of the Antarctic food web. Phytoplankton are sensitive to increased UV-B doses, resulting in decreased mobility and orientation, and changes in photosynthetic and enzymatic reactions. These effects may lead to reduction in primary productivity, which indirectly affects higher trophic levels. Because humans and other consumers are dependent on higher species such as fish and shrimp, populations outside the local ecosystem are potentially at risk. Prokaryotic microorganisms responsible for nitrogen fixation are also susceptible to UV-B, which could result in changes in the biogeochemical cycling of nitrogen, potentially leading to detrimental effects on plant growth. Other possible indirect effects of higher UV-B stress are decreased planktonic production of dimethylsulfide (DMS), an important source of sulfur and cloud condensation nuclei to the atmosphere, and reduced uptake of CO2 by the oceans.

Global climate may also be influenced by Changes in Tropospheric Chemistry. Studies have suggested that the recent slowdown in the rate of increase of methane levels in the atmosphere may be due, in part, to increased UV-B irradiance in the lower atmosphere. Photochemical smog production in urban areas would also increase under enhanced UV-B levels, reducing air quality and leading to possible effects on human health and agriculture.

GROUND LEVEL OZONE
What is it?
Though it acts as a protective layer high above the earth, ozone can be harmful to breathe. It is the prime ingredient of smog, in our cities.

Why is there a problem?

Ozone is not emitted directly into the air but rather is formed by gases called nitrogen oxides (NOx) and volatile organic compounds (VOCs) that react with oxygen in the air in the presence of strong sunlight, creating effects of concern when temperatures are higher during summer.

Ground-level ozone forms readily in the atmosphere in hot weather. On warm days, VOCs and NOx "bake" together in the sun forming ozone concentrations which can remain high over large regions. Many urban areas tend to have high ozone levels. However, areas downwind of urban settings are also subject to high ozone exposure, as winds carry VOCs and NOx from their original sources.

Changing weather patterns (especially the number of hot, sunny days) and periods of air stagnation create yearly differences in ozone concentrations. It is often difficult to make long-term predictions concerning ground-level ozone because the number of "bad" ozone days varies greatly from one year to the next and there are so many factors which influence ozone formation.

Health and environmental effects of ground-level ozone

When inhaled, ozone can damage the lungs.

Relatively low amounts of ozone can cause chest pain, coughing, nausea, throat irritation, and congestion. It may also worsen bronchitis, heart disease, emphysema, and asthma.

Healthy people as well as those with respiratory problems, experience breathing problems when exposed to ozone.

The Environmental Protection Agency has established a maximum ozone health standard. A single hour of exposure to ozone at this level is sufficient to cause negative respiratory effects. In fact, 13 million U.S. adults are currently exposed to ozone levels above the health standard for at least one hour in the summer. During heavy exercise these people are at particular risk for short-term health effects. Many more individuals may be repeatedly exposed to lower ozone levels which may cause long-term adverse effects. About 64 million people live in areas with ozone levels greater than the maximum health standard.

Ground-level ozone interferes with the production and storage of starches within plants, reducing their growth rates.

It damages the quality of crops (such as corn, wheat, and soybeans), making them less valuable on the market and can substantially reduce crop yield.

Ozone reduces the ability of trees and plants to fight disease. It is estimated that agricultural crop losses of $2 to $3 billion dollars per year can be attributable to ozone exposure. The extent of forest damage is currently being studied. Ozone has been shown to damage various tree seedlings.

What is being done about the problem?

The Clean Air Act of 1990 requires EPA, states, and cities to initiate a series of programs that will further reduce emissions of VOCs and NOX from cars, fuels, industrial and chemical facilities, power plants, and consumer and commercial products among other sources. Cleaner cars and fuels, new kinds of gasoline nozzles, enhanced vehicle inspection, and other programs will be phased in over the next decade.



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HIGH ALTITUDE OZONE

What is it?
In the stratosphere, high altitude ozone forms a protective layer 10 to 35 miles above the earth to shield us from the sun's harmful ultraviolet (UV) rays. Ozone is naturally produced and destroyed at a constant rate in the stratosphere.

Why is there a problem?

Stratospheric ozone is gradually being destroyed by chemicals called chlorofluorocarbons (CFCs) and other ozone-depleting substances. These ozone depleters degrade slowly and can remain intact until they reach the stratosphere. There they are broken apart by the sun's ultraviolet rays. This reaction sets free the chlorine or bromine molecules of these chemicals, allowing them to attack and destroy the protective ozone blanket.

It can take decades for them to reach the upper atmosphere. Ozone-depleting substances released today will contribute to ozone destruction many years from now. One CFC molecule can lead to the elimination of 100,000 ozone molecules. Consequently, ozone is disappearing much faster than it is being replaced naturally.

Satellite information indicates ozone losses on as a global scale. The most significant losses have occurred over the North and South Poles, because ozone depletion occurs rapidly in extremely cold weather conditions. Fluctuating weather cycles affect the level of ozone in the stratosphere. This makes it difficult for scientists to accurately predict the future condition of the ozone layer.

Health and environmental effects if high-altitude ozone is decreased

If destruction of the ozone layer continues, more harmful ultraviolet rays will reach the earth's surface and its inhabitants, leading to increases in the number of skin cancer cases and eye cataracts (which can cause blindness). The United Nations estimates a 26 percent increase in skin cancer cases, 1.6 million more cataract cases, and 24,000 deaths from melanoma (a serious form of skin cancer) worldwide by the end of the decade.

Ozone depletion/increased ultraviolet rays will also damage UV-sensitive crops, such as soybeans.

Additionally, ozone depletion is suspected to cause decreases in phytoplankton, a plant within the ocean. Decreased phytoplankton could:

reduce fish populations (since phytoplankton is an important plant/food source in the marine food chain).
increase the level of carbon dioxide in the atmosphere, because plants "breathe in" carbon dioxide and "breathe out" oxygen.
Increased UV radiation can also be instrumental in forming more ground-level ozone.
What is being done about the problem?

In 1987 the United States entered into as a series of international agreements called the Montreal Protocol which were designed to limit and eventually eliminate world-wide production of ozone-depleting substances by the turn of the century. Under the Clean Air Act of 1990 the US Environmental Protection Agency (EPA) is accelerating the schedule for phasing out CFCs and certain other ozone-depleting substances to the end of 1995.

The Clean Air Act requires the use of written labels on all products containing CFCs or similar substances and prohibits non-essential ozone-depleting products such as fog horns. In addition, the CAA prohibits releasing car and home air conditioner refrigerants or appliance refrigerants into the atmosphere.



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WHAT CAN YOU DO?
High Altitude Ozone:
Make sure that technicians working on your car air conditioner, home air conditioner, or refrigerator recover the refrigerant (This is required by law).
Have your car and home air conditioner units and refrigerator checked for leaks. When possible, repair leaky air conditioning units before refilling them.
Properly dispose of refrigeration or air conditioning equipment (This is required by law).
Protect yourself against intense sunburn. Wear UV-screening sunglasses and hats to shield yourself from harmful rays. Also, apply sunscreen.
Ground-Level Ozone:
Keep your automobile tuned-up and well-maintained.
Carpool and/or reduce driving.
Be careful not to spill gasoline when filling up your car or gasoline-powered lawn and garden equipment.
Make sure your tires are properly inflated and your wheels aligned.
Participate in your local utility's energy conservation programs.
Seal containers containing household cleaners, workshop chemicals and solvents, and garden chemicals to prevent volatile organic compounds (VOCs) from evaporating into the air.

Answer 2

Environmental Effects Of Ozone Depletion

Answer 3

You would not believe it but its true and its not true The devil is makeing it happen his way of covering it up is too make us believe it is not real yet makeing us know it is so as the matter grows worse and we have the un and the goverments working on the issue and people donateing for it nothing happens we do nothing at all the world just lets it keep growing worse while we seem to think things are being worked on but thats not true see we have this agenda that has been made by the devil too let the world over populate let the world go too hell so he can be in control once it gets so bad its noticeable and its so bad our food our water our earth will have too heal no matter what it is a way for the devil too begin the one world goverment too control us that is whats up its the devils plan all that going green sustainable stability stuff is the devil's plan open your eyes and see something is wrong something is terrible :( its going too happen very soon he is a angel of light but as evil as hell too trick us he tricks us by creating this companys and going green and all this stuff climate change too control us soon litterly like cattle marked branded and lots of blood and death as we are killed and used and slaved the world hasnt opened there eyes yet too this look at the world and see that its getting worse no limit on population babys being born all the time china is full of population and pollution japan the fukashima thing and all this stuff going on that not much is being done too stop any of it all these things are adding up and we give our money too going green and all these things and thirsty for oil in other countrys when we have tons of oil lots never ending here at home united states be ready have a ear and understand what im saying the devil is crazy his biggest plan too blind us from it all and let it go day by day till its so bad something has too be done so Drastically we are all controlled food everything will be depleted the earth will be depelted because of the devil you have been warned im not fooling or jokeing look into it guys

Answer 4

Ther is a natural layer around the earth that protects it from the ultra-violet rays.
It gets damaged and worn out by a chemical named as ChloroFluoroCarbons (CFC), present in the refrigerators. This chemical has no immediate harm to humans but it depletes the o zone layer that leads to free entrance of ultra violet rays. This exposure to uv rays may cause skin burns and even may lead to skin cancer.

Furthermore, There is a patch of atmosphere over Aus. where the o zone layer has been depleted. This has been a big cause of concern for the aus. govt.

Answer 5

Ozone Layer's key role is prevent U.V rays from entering into atmosphere.
Due to presence of some free radicals like Chlorine(mono atom)
ozone layer breaks, thereby forming holes. Mechanism:
ozone = O3 This is formed by absorption of U.V and when O2 and O react.
After Effects: Due to Ultra Violet rays falling on us it can cause skin cancer , cataract and other cancers .

Answer 6

Depletion of ozone.
Less ozone

Answer 7

Ozone is made of O3 atom when it get contacted with the gases of the type CFC they get broken into ordinary oxygen atom and oxide gases resulting in the reduction of the thickness of the gas layer known as deplition.

Its after effects are the inference of the harmful radiations and increase in the global temperature

Answer 8

in our upper atmostphere there is a layer of ozone which protects us by absorbing UV light coming from the sun. The depletion of this layer (and the holes in it) allow more UV to get through and damage our skin.. which causes skin cancer, etc.