Ultraviolet Radiation

IRVINE, Calif. -- Chemicals that are eating a hole in the Earth's protective ozone layer are still being released into the air at a record level despite international agreements to phase out their use, says the scientist who first spotted the phenomenon 17 years ago.F. Sherwood Rowland, a University of California scientist who discovered the link between chlorofluorocarbons, or CFCs, and the ozone layer, has released the results of tests that show emission of the chemicals reached a record high this year and are growing.

In the nation's wetlands, ponds and nature preserves, deformed frogs are turning up in record numbers.Like other amphibian populations, the number of frogs has been declining for decades. That's reason enough for concern, given the delicate ecological balance between all living things.But this latest development really has scientists worried. Why?It all began in the summer of 1995, when a group of middle-school kids from the Minnesota New Country School in southern Minnesota made a startling discovery on a field trip to a local pond.

THE CURRENT wild weather through the West and Midwest has again raised the question: Is global warming finally asserting itself?The best answer science can give us now is essentially: "It is the kind of weather we would predict global warming to make more common."Whether we are unnaturally changing the Earth's climate by pumping unprecedented amounts of carbon dioxide into the atmosphere is one of the most important issues of our time.Predicted consequences include more extremes of weather, flood and drought, loss of species diversity and a rise in sea level that would devastate coastal regions such as the Chesapeake.

You probably have heard of ozone, the Dr. Jekyll and Mr. Hyde of chemicals. It is an odd form of oxygen, a gas that normally floats around as O2. Ozone is O3, and it occurs naturally in a gaseous layer in the stratosphere, seven miles above the Earth.This high layer of ozone acts as a selective shield around the Earth. It absorbs intense ultraviolet radiation from the sun that would otherwise make life here difficult, if not downright nasty.Ozone is also found in the lower atmosphere, where it is created when certain byproducts of combustion react with sunlight.

The buildup of chlorofluorocarbons in the atmosphere appears to be slowing for the first time since the compounds came under attack as destroyers of the planet's protective ozone layer, says one of the scientists who first identified the problem."

sunbathing at the beach, picking fresh corn in the field or taking adaylong hike in the woods are the kinds of activities that many waitfor all winter.But if you're not careful, the joys of summertimecan turn your skin into the pain of a lifetime at a moment's notice.Taking care of the body's largest organ -- a 150-pound man's skin, if stretched out, would cover 20 square feet -- is obviously a year-round task.But in the summer, when warm weather causes us to shed clothes and expose more of the skin to the elements, skin problems are more common.

The minute she saw the place, she loved it. A two-story 1920s wood frame house painted celadon green with a back yard and a brick fireplace. She grabbed it, not giving a moment's thought to the toxins that could lie hidden within.Lead lurking in layers of paint. Nasty asbestos in the basement. Invisible radon gas or excessive carbon monoxide. She hasn't yet gotten around to checking for the potentially hazardous electromagnetic fields around her color TV set or for possible radiation leakage from the microwave.

Bill Milne writes from sunny Sykesville: "Tell me about the UV Index. ... How much stronger is a value of 9 than a value of 7?" The UV Index, forecast below, is not a direct measure of ultraviolet radiation. It combines predictions of the sun's height at solar noon, atmospheric ozone (which blocks UV rays), local elevation and cloud cover, and estimates the UV dose rates to the skin. The World Health Organization says 0-2 is "low;" 3-5 is "moderate;" 6-7 is "high;" 8-10 is "very high." Just use sunblock.

WASHINGTON -- The Food and Drug Administration proposed yesterday that all sunscreens and tanning products be required to carry warnings about the dangers of sun exposure and that cosmetic products promoting tanning but offering no screen against the harmful rays of the sun display a warning that they do not protect against sunburn."

Chilean scientists say they are receiving reports of increases in skin allergies and sunburn among schoolchildren and of vision loss among sheep in the southernmost areas of the country. They attribute the phenomena to increased solar radiation caused by depletion of the ozone layer over the Antarctic.Chilean researchers said they believed that the sheep were getting cataracts from exposure to ultraviolet rays that would normally be blocked by atmospheric ozone. They also expressed their concern about the long-term impact on people and animals, although no increase in skin cancer has been reported in southern Chile.