ozone test essentials

What is the Montreal Protocol?

24 nations met in 1987 in Montreal, Canada to reduce the production of CFCs; The agreement they all signed became known as the Montreal Protocol

What will one of the consequences of restoring the ozone layer probably be?

A 1998 study by the World Meteorological Organization hypothesized that restoring the ozone layer will lead to an increase in global warming; Ozone depletion in the stratosphere has been cooling the troposphere and has helped offset or disguise as much as 30% of the global warming from our emissions of greenhouse gases

In the breakdown of the ozone layer, the ozone directly reacts with?

A chlorine atom that has been liberated by the breakdown of the CFC molecule by ultraviolet light

What is ozone?

An ozone molecule consists of three (3) oxygen atoms bonded together

How long did Rowland and Molina calculate each CFC molecule could last in the stratosphere?

Depending on the type of CFC, each molecule was found to last in the stratosphere for 65 to 385 years; During its lifetime, each chlorine atom released from CFCs can convert 100,000 m

What causes the ozone hole?

Each winter, steady winds blow in a circular pattern over the Earth's poles; This creates a polar vortex (a huge swirling mass of very cold air that is isolated from the rest of the atmosphere until the sun returns a few months later)

What did the formation of the ozone layer allow?

enabled life on land to evolve

What did a 2003 study find?

found that women who used tanning parlors once a month or more increased their chance of developing malignant melanoma by 55%

What are chlorofluorocarbons?

known as CFCs for short; first CFC was discovered by Thomas Midgley, Jr. - a GM chemist in 1930; There are a whole family of "useful" CFCs; CFC-11 or trichlorofluoromethane (CCl3F) and CFC-12 or dichlorodifluoromethane (CCl2F2) are both types of freon

What is basal cell carcinoma?

most common skin malignancy usually caused by excessive exposure to sunlight or tanning lamps; It develops slowly, rarely metastasizes and is nearly 100% curable if diagnosed early and treated properly

What is malignant melanoma?

type of skin cancer occurs in pigmented areas such as moles anywhere on the body; Within a few months, this type of skin cancer can spread to other organs; UV-B radiation is responsible

What were CFCs used for?

used as coolants in air conditioners and refrigerators, propellants in aerosol spray cans, cleaners for electronic parts such as computer chips, fumigants for granaries and ship cargo holds, and bubbles in plastic foam used for insulation and packaging; They were used extensively between 1960 and early 1990

What are some conclusions from Rowland and Molina's research?

CFCs remain in the troposphere because they insoluble in water and chemically unreactive; Over 11-20 years these heavier-than-air chemicals are lifted into the stratosphere mostly through convection, random drift, and the mixing of air in the troposphere

What else can increases in exposure to ultraviolet radiation cause?

Excessive exposure to ultraviolet radiation also suppresses the immune system

If you want to decrease your exposure to UV radiation, what areas of the world should you avoid?

For at least part of the year you might want to avoid areas near the ozone hole like New Zealand, Australia, etc

What compound is most responsible for ozone depletion?

Freons are the compounds most responsible for ozone depletion; They were made in huge quantities and even though we no longer use them in most places around the world, we still have huge amount of them leaking slowly into the atmosphere

What parts of the atmosphere do what?

Global warming occurs in the troposphere and ozone depletion occurs in the stratosphere

What other chemicals affect the ozone layer?

Halons and hydrobromofluorocarbons (HBFCs) are used in fire extinguishers; Methyl bromide is a widely used fumigant in agriculture; Hydrogen chloride was emitted into the stratosphere by our space shuttle program; Carbon tetrachloride, methyl chloroform, n-propyl bromide, and hexachlorobutadie are all cleaning solvent CFCs are not the only Ozone-depleting Compounds (OD)

What happens when the vortex breaks up at the end of winter?

Huge masses of ozone-depleted air flow northward and linger for a few weeks over parts of Australia, New Zealand, South America, and South Africa; This raises biologically damaging UV-B levels in these areas by 3-10%, and in some years as much as 20%

If we continue to cooperate on the issue of ozone depletion, what can we expect?

If nations continue to follow the Montreal and Copenhagen Protocols, ozone levels should return to 1980 levels by 2050 and 1950 levels by 2100; These protocols set an important precedent for global cooperation and action to avert potential global disaster by using prevention to solve a serious environmental problem

What do you want to look like as you age?

If you want to stop the premature aging of your skin - stay out of the sun and don't smoke

The fact that increased skin cancer rates may not show up for 15-40 years following ozone depletion illustrates the concept of?

Lag time (there is a long period of time between exposure and a problem that develops

What is the single greatest contributor to CFC emissions in the United States?

Leaking air conditioners

What can you do to help protect the ozone layer?

Make sure the old air conditioning units in your homes and cars are not leaking; Don't purchase products that contain CFCs; Pressure legislators to ban all uses of CFCs, halons, and methyl bromide ASAP; Buy a new energy efficient refrigerator that uses more ozone friendly coolants

What other conclusions came from Rowland and Molina's research?

Once CFCs reach the stratosphere, the CFC molecules break down under the influence of high-energy UV radiation; This releases highly reactive chlorine atoms (Cl), as well as atoms of fluorine (F), bromine (Br) and Iodine (I), which accelerate the breakdown of ozone (O3) into O2 and O in a cyclic chain of chemical reactions This causes ozone in various parts of the stratosphere to be destroyed faster than it is formed

What was the Montreal Protocol followed by?

Other agreements refined the original Montreal Protocol -the London Protocol in 1990 and most recently the Copenhagen Protocol which accelerated the phasing out of key ozone-depleting chemicals

What else can increase your risk of skin cancer?

Sunburns that produce blistering and severe sunburns in childhood are thought to be especially hazardous, increasing the risk of melanoma in later life

How quickly was this problem addressed?

The CFC industry (especially DuPont) attacked their research; After 14 years of denying CFCs were a problem, DuPont officials acknowledged in 1988 that CFCs were depleting the ozone layer and agreed to stop making them once they found substitute

What is the ozone hole?

The observed loss of ozone above Antarctica; A more accurate term is ozone thinning because the ozone depletion varies with altitude and location

Who were the two scientists who "busted" CFCs?

The research of Sherwood Rowland and Mario Molina in 1974 was the first to indicate that CFCs were lowering the average concentration of ozone in the stratosphere; They shocked both the scientific and the CFC industry (worth $28 billion a year) with their call to ban these chemicals; They were later awarded the Nobel Prize

What do most people not realize?

There is a significant lag time between our exposure to harmful ultraviolet radiation and any subsequent skin cancer we may develop

What are the characteristics of CFCs?

They are chemically stable (nonreactive), odorless, nonflammable, nontoxic, and noncorrosive compounds -they are dream chemicals; In 1974 two chemists found the dark side of cfcs

Is ozone useful in the troposphere?

Tropospheric ozone is harmful air pollutant that damages plants and human health Ozone in the stratosphere screens out mutagenic ultraviolet radiation

Why do we care about ultraviolet light?

UV-A rays and UV-B rays can be very harmful to humans and other organisms ; With less ozone in the stratosphere, more biologically damaging UV-A and UV-B radiation reaches the Earth's surface giving humans more severe sunburns, more eye cataracts, and more skin cancer

What does the ozone layer block?

UV-C, the shorter wavelength, higher-energy UV b and it absorbs some of UV-B Very little of UV-A is blocked

What can we do to protect ourselves?

Use sunscreens and sunblocks; stay out of the sun; Wear sunglasses with UV protection; Wear a hat; Protect your skin with clothing; Demand better labeling on the sunscreen products we purchase

What happens next?

Water droplets in clouds enter this circling stream of frigid air and form tiny ice crystals that collect CFCs and other ODCs on their surfaces; This sets up conditions for the formation of ClO, the molecule most responsible for the seasonal loss of ozone over the Antarctic