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03/05/2008
Atmospheres
Frank Sherwood Rowland and I share a number of things in
common. We were both born in 1927. He skipped fourth grade
while I skipped first and 12th grades. We both entered college in
1943, he at Ohio Wesleyan, I at Dickinson. We both loved
baseball; I got my varsity letter in baseball at Dickinson and he
not only played semipro ball in Canada but also managed a team
that won the Canadian championship. In graduate school, we
both worked with radioactive atoms, he with bromine and I with
sulfur. There are some differences, however. He stands 6 feet 5
inches while I’m only 5 feet 8 inches (used to be 5’10”). Oh,
Rowland was awarded a Nobel Prize; I’ve gotten a couple of
awards but none anywhere near the prestige or importance of a
Nobel.
What prompted this column on Rowland is an article by Bette
Hileman on the man titled “A Giant Among Chemists” in the
December 24, 2007 issue of Chemical and Engineering News
(C&EN). I’ve probably written about Rowland in an earlier
column but in these days of concern about global warming and
with many still questioning its existence, it’s worth recalling
Rowland’s work over three decades ago that showed man can put
things into the atmosphere with global consequences. The 1995
Nobel Prize in Chemistry was awarded to Rowland, Mario
Molina and Paul Crutzen for their work showing how
chlorofluorocarbons (CFCs), notably Freon used in refrigeration,
aerosol sprays and the like, destroy ozone in the stratosphere.
In 1972, Rowland attended a conference in Florida where work
by a British scientist, James Lovelock, was reported. Lovelock
had detected CFCs in the atmosphere in an amount almost equal
to all the CFCs ever produced to that point. It was assumed at
the time that the CFCs were inert and were of no threat in the
atmosphere. Rowland, however, realized that if the CFCs
reached the stratosphere, up there some 8 to 30 miles above the
earth, it would be a different story. Specifically, he believed that
short-wavelength ultraviolet radiation would break down the
CFCs.
In late 1973, Rowland and Molina, a postdoc in Rowland’s group
at the University of California, Irvine, calculated that the UV
radiation would cause the CFCs to lose chlorine atoms. These
chlorine atoms would then react in a sort of chain reaction with
the ozone and lead to a reduction in the amount of ozone in the
ozone layer that protects us earthlings, as well as other plant and
animal life, from the powerful UV radiation. They calculated
that, if CFC production continued at the rate at the time, 7 to 13
percent of the ozone layer would be lost. Actually, the rate of
CFC production was then rising at about 10 percent a year and
the researchers predicted the ozone layer losses would be even
greater.
Rowland and Molina realized the importance of their
calculations and submitted a paper to the journal Nature. The
paper was published in June that year. Crutzen, a meteorologist,
was among a group of scientists who confirmed the calculations
shortly afterward. By 1976, the scientific community and
Congress got into the act and the U.S. banned nonessential uses
of CFCs in aerosol propellants. However, Europe and Japan
continued using CFCs as aerosol propellants and CFCs were still
being used worldwide as refrigerants.
Reminiscent of today’s skeptics on global warming, there was
strong resistance to the calculations from the CFC industry, not
surprising, but also from some scientists and government
officials. The argument was that these were only calculations
and that there was no proof that the ozone layer was being
affected. Unbelievably, it turned out that the data was there all
along. The British Antarctic Survey had been measuring the
total amount of ozone in the atmosphere for decades. The
unbelievable part is that the instrument used to measure the
ozone was programmed to reject what were considered “outliers”
in the data. That is, any measurement that seemed too high or
too low was eliminated from the final output of the instrument!
Well, in 1984, ten years after the publication of the paper in
Nature, Joseph Farman and his colleagues at the British Antarctic
Survey decided to look at the raw data from the instrument and,
sure enough, they found that since the 1960s the ozone layer was
greatly reduced and in 1985 they published a paper in Nature
showing a 40 percent reduction in the ozone layer in late
September. Their results were confirmed the next year by
satellite data. By 1987, the world finally was convinced and the
path to a total halt in the use of CFC and other ozone-depleting
compounds had begun.
All this is history. I was intrigued that, at my age, 80-year-old
Rowland is still at UC Irvine and he and another chemist, Donald
Blake, head a research group that still studies the atmosphere.
Only now they define two atmospheres – the conventional one
and another they call the “inner atmosphere”. They continue to
study the trace amounts of various compounds such as methane
in the atmosphere and have postulated that ups and downs in
methane concentrations are related to such factors as uncapped
old oil and gas wells and to burning of biomass, e.g., forest fires.
Decreases in the amount of methane are thought most likely to be
due to capping of leaks in the oil and gas wells. On the other
hand there have been periods of increases in both methane and
ethane, which are attributed to large conflagrations such as the
1997 fires in Indonesia.
The Irvine group has also been studying the inner atmosphere of
breath. Specifically, they want to know what we breathe in and
out. Two of their studies involved diabetics and cystic fibrosis
patients. The atmosphere has a concentration of a compound
called carbonyl sulfide, roughly at a level of about 600 parts per
trillion (ppt). Normally a healthy person breathes in the 600 ppt
and exhales only about 350 ppt of the compound. On the other
hand, cystic fibrosis patients exhale about 490 ppt of the
compound. The speculation is that bacteria in the lungs of the
CF patients make carbonyl sulfide, accounting for the higher
level in their breath. Thus there’s the possibility that measuring
the breath could lead to a method of measuring the amount of
bacteria in the CF lungs.
In diabetics, the group has found that as the blood sugar goes up
in diabetics there is an increase in the compound methyl nitrate
in the breath. If a convenient test for methyl nitrate can be
developed, there’s a chance that it could replace the need for
sampling of blood. At 80, Rowland is still making contributions
on a global as well as on a very personal scale.
Finally, I want to thank readers Charles K and Steve G, a former
neighbor, for their interest in my wife’s condition. I’m happy to
say that this week I got her out to the mall for a walk, her first
since her fall on January 9. And yesterday we attended a mall
walkers luncheon at a Chinese restaurant in the area, her first
meal out since coming home from rehab. That meant yesterday I
didn’t have to cook. Things are looking up!
Allen F. Bortrum
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