Learning to Respect the Ozone
IN DECEMBER, the world watched with special interest—and perhaps relief—as the United States halted its manufacture of a familiar household item, the fluorocarbon aerosol spray. The long-awaited ban is a government response to scientists who warn of possible climate changes and increased skin cancer on every continent.
“What?” you may ask. “Could by little can of spray really damage the world?”
Maybe or maybe not. But if your aerosol spray uses fluorocarbon gas as a propellant, three government agencies in the United States feel that the risk is too great to take chances. Jointly the Environmental Protection Agency, the Food and Drug Administration (FDA) and the Consumer Product Safety Commission will enforce a new ruling. No company may use fluorocarbon propellants in nonessential products after December 15, 1978. Why? “Because chlorofluorocarbons may deplete stratospheric ozone, leading to an increase in skin cancer, climatic changes, and other adverse effects,” says the final rule.
Behind this ruling lies the story of how man learned to respect that protective shield overhead—the tenuous layer of modified oxygen called ozone. Simply stated, man sees the ozone as earth’s filter against harmful radiation from the sun. Destroy the filter and you destroy life on earth. To read in Revelation 11:18 of “those ruining the earth,” is one thing. It is another thing to hold in your own hand a spray can accused of such ruin.
Are the Aerosols Poison?
Generally speaking, the fluorocarbons are remarkably safe and nonpoisonous. They resist uniting chemically with your food, your water or your body tissues. But, because the fluorocarbons do not react with anything in the atmosphere around us, they linger a long time. Ironically, this property that makes the propellant gas so harmless at earth’s surface enables it to persist and eventually reach a place where it can work against man. As the years pass, normal air circulation carries it up into the stratosphere, where things are quite different.
In the upper atmosphere, many scientists point out, the high-energy rays in the sunlight may well react with fluorocarbons to release free chlorine atoms. Chlorine, in turn, can change ozone into common oxygen, and free chlorine gets used over and over almost endlessly. It becomes a catalyst—a tool in a chemical reaction that breaks down the ozone. Herein lies the potential danger. This long-range depletion of the ozone is what scientists fear from the tiny puffs of millions of fluorocarbon spray cans.
Time is a big factor in this theory. Fluorocarbons are thought to take as long as 10 to 15 years to reach the stratosphere. And it may take a century or more for the ozone to replenish itself from damage already done. The threat, if real, is to future generations.
The natural layer of ozone 10 to 30 miles (16 to 48 kilometers) overhead filters out some of the sun’s heat rays, the “infrared” light. Excess heat rays from the sun could cause drastic shifts in the earth’s weather. More importantly, the ozone layer also shields us from most of the sun’s ultraviolet light. The friendly ultraviolet that penetrates in normal sunlight gives many of us vitamin D and a suntan. But overexposure to the rays increases the danger of skin cancer, including the rare, often fatal, melanoma. Some cancer experts expect 2 percent more cancer for each percent less ozone. And if the more intense rays should kill tiny oxygen-generating plants adrift in the ocean, the oceanic “food chains” would suffer. Truly the ozone layer is a protection mankind cannot afford to disregard.
Why Haven’t We Heard of This Before?
Synthesized in the 1930’s and trade-named Freon, the nontoxic fluorocarbons raised no eyebrows until June 1974. Then scientists F. Sherwood Rowland and Mario S. Molina of the University of California sounded the warning. Others had devised mathematical descriptions (“models”) of how gas diffuses through the air. But Rowland and Molina showed how fluorocarbons in the sky could alter the quality of life on earth. Soon the University of Michigan, Harvard University and the National Center for Atmospheric Research, using similar models, came to the same conclusion.
Thus you are not alone if you heard only lately of the environmental threat to the ozone. It is new to everyone. Suddenly in the mid-1970’s man learned to respect the ozone.
Now came the agonizing problem. “Must we shut down a thriving industry due to a theoretical, though alarming, threat?” To find a substitute for Freon’s original use, as a refrigerant, would be difficult. But each year 500 million pounds of U.S. Freon production also went for use in spray cans. Ninety percent of the sprays were personal products like cosmetics, deodorants and hairsprays—growing in popularity world wide. And the United States, which produced half of the world’s fluorocarbons, was doubling its production every six years.
Deciding What to Do
With man’s scanty knowledge of air currents and photochemistry in the upper atmosphere, it is hard to say just how accurately the models predict the ozone depletion. But if they are anywhere near correct, there is great risk, and that possibility had to be faced. New techniques were put to use for testing the ozone layer. Measuring ozone by satellite and rocket supplemented the older “Umkehr” method of comparing two wavelengths of sunlight. Scientists had to interpret the results. Is there less ozone now, and does this correspond to the amounts of fluorocarbons released?
Early models of how fluorocarbons affect the ozone were one-dimensional. That is, they described mathematically what happens when the gas rises vertically to the stratosphere. The objection to this is that we live in a three-dimensional world. Winds blow, summer and winter storms come up, and no gas rises straight up. Besides, the natural ozone layer forms unevenly, more in summer and more toward the sunny equator. Moving steadily away from the equator, the ozone forms a denser blanket toward the poles. So researchers began suggesting two- and three-dimensional models considering season and latitude.
Gradually, as results came in, government agencies realized the need to act. A newspaper cartoon showed two creatures, not earthlings, in a spaceship. “Our instruments must be wrong,” one said to the other. “They show that they’re destroying their ozone with deodorants.” The theory has not been conclusively “proved.” But the risk seemed too great to wait any longer. The United States has ended its major use of fluorocarbons as spray propellants.
As the FDA announced the ban, the Federal Register said:
“The agency has acted because the best estimates of the scientific community after careful examination are that chlorofluorocarbon release leads to a reduction of stratospheric ozone, that the ultimate consequences of ozone depletion at the estimated levels are unacceptable in the agency’s judgment, and that it is indefinite when the remaining scientific questions will be conclusively resolved.”
How Will It Affect Business—and My Pocketbook?
Some businesses will be hurt. One estimate is that 1,700 jobs will be lost over an 18-month phaseout period. In 1975, six companies in the United States produced fluorocarbons in 15 plants. The aerosol filler companies will take most of the impact of the ban. Those affiliated with cosmetic firms may be able to convert to carbon dioxide and hydrocarbon propellants fairly easily. Smaller firms may go out of business. They operate under contract and may lack the funds to convert to other propellants.
The good news for your pocketbook is that safer, cheaper substitutes may be on the horizon. For some time consumers have looked for products that do not come in spray cans. Those who make, package and sell cosmetics and toiletries have introduced roll-ons and finger-driven atomizers, usually at a saving to users.
Interestingly, too, the environmentally safer carbon dioxide and hydrocarbon gas propellants are cheaper. In 1977 the FDA estimated that the switch to these substitutes would result in consumer savings of from $58 million to $240 million (U.S.) annually. Time will tell how much of this reaches your pocketbook.
But far outweighing any financial considerations is the peril of a gradual catastrophe to mankind and all earthly life. The destruction of our natural filter against dangerous rays from the sun would surely rank as the greatest blunder that man had committed in his pursuit of technology. And how sickening would be the realization that irreparable damage had already been done, leaving us helpless to avert the consequences! The consensus is that man learned to respect the ozone just in time. Someday, looking back, we may realize that we had an appallingly narrow escape.
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SUNLIGHT PLUS AEROSOL DEPLETES OZONE IN STRATOSPHERE BAND:
1. Ultraviolet rays break chlorine away from fluorocarbon
2. Chlorine acts as a “catalyst,” turning ozone into ordinary oxygen
3. Allows more ultraviolet rays to reach earth
50 MILES (80 KILOMETERS)
30 MILES (48 KILOMETERS)
FLUOROCARBONS MAY TAKE 10 TO 15 YEARS TO REACH THE STRATOSPHERE
10 MILES (16 KILOMETERS)
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THE OZONE DEPLETION THEORY
(IN THE CHEMIST’S SHORTHAND)
Scientists estimate that fluorocarbons—more correctly called chlorofluorocarbons—released from someone’s spray can as long ago as 10 or 15 years are only now reaching the stratosphere.
THEY CALL IT “PHOTOLYSIS”
At altitudes above 15 miles (25 kilometers) sunlight has enough energy to tear chlorine free from fluorocarbons. “Photolysis,” the scientists call this, when electromagnetic waves (such as light) decompose chemicals. To see how this works, suppose you used a deodorant a decade ago with the propellant Freon II (CFCI3). Here in chemist’s shorthand is what may be happening to that Freon in the sky:
hv + CFCI3 → CFCI2 + CI
Here hv is a photon, a bit of light energy. Striking a drifting molecule of your long-forgotten Freon II, it yields (shown by the arrow) a smaller molecule plus a free chlorine (CI) atom. What happens next?
OZONE BECOMES PLAIN OXYGEN
Chlorine atoms decompose ozone molecules by stripping away one of their three oxygen atoms. The chemist writes it like this:
CI + O3 → CIO + O2
Here CI is free chlorine, O3 is ozone and O2 is plain oxygen. But the leftover chlorine oxide (CIO) does not last. It meets stray oxygen atoms, O, rather abundant up there.
CIO + O → CI + O2
Note, if you follow the arrows, that again we get plain oxygen (O2). But the chlorine (CI) is free to find its next O3 victim. That makes free chlorine a catalyst. It does this over and over before it finds a rare chemical up there to take it out of circulation. Thus, the theory goes, a little aerosol may deplete a lot of ozone.
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“Do you mean that this . . . may lead to this?”