Friday, May 8, 2009

What you do to save the ozone layer

When a health issue involves the health of the planet, people often feel there is little they can do to change the course of events. The depletion of the earth is protective ozone layer is one of these mega-issues. While most of the measures needed to safeguard the ozone layer involve nations and industries, there are significant steps you can take - as an individual consumer and as a member of a society.

There's good and bad ozone, depending on where it is, though both are chemically identical-a gas formed when three atoms of oxygen, rather than the normal two, bind together. The ozone found at ground level, a by-product of car and factory pollution, is one of the more dangerous components of smog. But in the earth's stratosphere, about 10 to 25 miles above us, ozone functions as a natural screen against the sun's most damaging ultraviolet (UV) rays. Unfortunately, the ozone that pollutes our air cannot reach the stratosphere's ozone layer.

What CFCs do

The stratospheric ozone layer is being destroyed in large part by man-made components called chlorofluorocarbons, or CFCs. These versatile chemicals, in liquid or gaseous form, have helped shape modern society. CFC s are used in coolants in our homes, cars and refrigerators; as foaming agents in foam insulation, mattresses, and food packaging; and as solvents that remove impurities from computer microchips and electronic equipment. The same properties that make CFCs efficient and safe for so many industrial uses also make them destructive for the environment. Their great stability ensures that when they are released into the air (during manufacturing, from leaky cooling systems, or upon disposal) CFCs eventually rise intact into the stratosphere, where radiation breaks them down into component atoms. One of these atoms, chlorine has a devastating effect on ozone. Other compounds called halons, used in some fire extinguishers, are even more destructive of ozone.

Scientists predict that by allowing more UV radiation to reach the earth, the depletion of the ozone layer will lead to an increase in the number of cases of skin cancer (especially melanoma) and cataracts. In addition, they postulate that the increased UV radiation may damage crops, kill plankton that serve as a food source for marine life, and even have adverse effects on the human immune system. CFCs may also trap heat in the atmosphere and thus contribute to the global warming trend (greenhouse effect).

For all these reasons, an international agreement in Montreal in 1987 called for phasing out CFC and halon production, and this past May in Helsinki these nations agree to rate the timetable. Recent reports by NASA that the ozone layer is being depleted even more rapidly that was previously projected, and the discovery of vast holes in the layer over Antarctica and the Arctic, have prompted scientists and environmental groups to call for a complete and rapid phase-out of CFCs. But even if we stopped using CFCs tomorrow, the damage to the ozone layer will continue, since those CFCs already released into the air will still be making their way to the stratosphere a decade from now and destroying the ozone for up to a century.

Substitutes have already been found for certain uses of CFCs. For instance, the EPA banned the use of CFCs as propellants in most, but not all aerosol sprays in 1978. CFCs can be modified so they do much less damage to the ozone layer, or so that they break down quickly in the lower atmosphere. Industries are also seeking ways to recycle the chemicals so that they aren't released into the air. Dupont, the world's largest manufacturer of CFCs, last year announced that it would phase out production by the end of the century.

Seven steps

The U.S. remains the biggest producer and consumer of CFCs. By following these steps, you can help reduce the American contribution to the destruction of the ozone layer.

* Have your car's air conditioner carefully serviced. Auto air conditioners are the single largest source of CFC emissions in the U.S. Don't simply refill your leaky air conditioner; if you don't have the leak fixed, the CFCs you leak will end up in the air. Go to a service station equipped to recycle the refrigerant (this costs an additional $35 to $55); otherwise, the CFCs will be vented into the atmosphere. In Los Angeles, an ordinance requiring service stations to recycle CFCs is expected to go into effect by January 1, 1990; it will also ban the sale of small cans of refrigerant, which allow people to 'top-off' their car air conditioners instead of repairing leaks. Car air conditioners using less harmful refrigerants are expected to be available in the mi-1990s. (Home air conditioners contain coolants that are far less ozone depleting.)

* Don't use foam plastic insulation in your home, unless it is made with ozone safe agents. Or use fiberglass,

gypsum, fiberboard, or cellulose insulation. * Don't buy a halon fire extinguisher for home use. * Check labels on aerosol cans. VCR-head cleaners, boat horns, spray confetti, photo negative cleaners, and drain plungers are still allowed to contain CFC's but such labeling isn't required.

* When buying a refrigerator, choose an energy efficient model: it may contain as little as half the CFC's. Thus when the fridge wears out and you dump it, less CFCs will be released. All refrigerators sold in the U.S. contain CFCs. To keep your fridge in the best working order, clean the coils regularly; that way it may last until CFC-free models are developed, or at least until recycling programs for CFCs are available. * If you feel strongly, write to your Senator and Representative and to President Bush, urging them to protect the ozone layer by tightening regulations on CFCs and halons, speeding up their elimination, mandating warning labels on products containing them, and pressing other nations to take such steps. Substitutes for CFCs may add to the cost of many products, be less efficient,, and have other drawbacks, at least at first. This may be hard to accept, especially since CFC emissions are invisible, and most of the damage they cause may not be evident for decade. But the steps we take now to protect the ozone layer will benefit our grandchildren.


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