Ozone can drop to pollution level

OZONE high in the stratosphere is helpful because it filters out the sun's most energetic and powerful rays - ultraviolet rays. But in the lower atmosphere, in the air that we are breathing, ozone is part of smog. It is created by pollutants from power plants, cars and paint solvents.

Why do ultraviolet rays destroy sea life? The photosynthesis process in plants is damaged when they are exposed to ultraviolet light. Ultraviolet light has a higher level of energy than regular light.

Because these wavelengths are short and energetic, they disrupt the activity going on in the molecules of the plant. Phytoplankton is a single-celled green plant that lives at the surface of the ocean, and therefore is exposed to a lot of ultraviolet light, which can destroy it. This little green plant feeds other small sea animals, which in turn feed bigger sea animals.

What are CFCs? CFCs are man-made chemical gases used for a variety of purposes. They are used in refrigerators, electronic-equipment cleaners and some paint solvents. The most common use is in automobile air conditioners. A CFC molecule is deadly in the upper stratosphere. One CFC molecule can destroy 100,000 ozone molecules! Why did people start using CFCs? In 1928, when CFCs were first invented, they were considered to be a great improvement over other coolants used in refrigeration. CFCs do not corrode metals, they aren't poisonous and they aren't flammable.

Will sunscreen provide enough protection in summer? There are two types of ultraviolet rays - ultraviolet-A (UV-A) and ultraviolet-B (UV-B). UV-B is the burning ray.

Scientists now think that UV-A may penetrate deeper into the skin and cause more harm. Sunscreens are usually rated based on the UV-B rays that they can block.

What is the difference between the ''greenhouse effect'' and ''ozone depletion?'' Both are serious environmental problems. The greenhouse effect, or gradual warming of the Earth's atmosphere, is caused by the buildup of carbon dioxide, methane, nitrous oxide and other pollutants.

These gases are released into the air from cars, factories, burning forests and fertilisers, to name a few sources. These gases trap the sun's heat.

The ozone layer, on the other hand, is supposed to absorb many of the sun's dangerous ultraviolet rays. But as ozone disappears, more rays pass through to the Earth.

What can the average person do to help? To help protect the ozone layer, consumers can help. Don't buy aerosol cleaners for the VCR, sewing machine or electronic equipment.

Also photographer's dust remover, canned boat horns and halon fire extinguishers should be avoided. Leaking auto air conditioners are the worst offenders.