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| SCIENCE TRIBUNE | Thursday,
December 26, 2002, Chandigarh, India |
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Radioactivity
in cigarettes Stem
cell research on slow track |
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Radioactivity
in cigarettes I do not claim
any originality in my efforts. In 1982, hundreds of smokers kicked the
habit after reading an article titled "Radioactivity in Cigarette
Smoke" in the New England Journal of Medicine. T.H.Winters and
J.R.DiFranza of the University of Massachusetts Medical Centre wrote
that cigarette contains radioactivity in the form of polonium-210
(Po-210) and lead-210 (Pb-210). T.C. Tso, a former researcher of the
US Department of Agriculture, discovered that the radioactivity in
tobacco came from phosphatic fertilisers, which contained uranium and
its decay product radium-226. Radium-226 decays into a series of decay
products. Among them Po-210 and Pb-210 are the most prominent. Sticky,
hair-like structures on both sides of tobacco leaves collect these
from the atmosphere. Tobacco roots may also absorb some radioactivity
from soil. Indian farmers do not use phosphatic fertilisers. In 1976,
scientists at the Bhabha Atomic Research Centre showed that the Po-210
levels in Indian tobacco are 10 to 15 times lower than those in US
tobacco. I knew this work very well as I gave them the equipment to
measure Po-210. Winters and DiFranza claimed that a person smoking 1
1/2 packs of cigarettes per day receives a dose to certain regions of
the lung equal to 300 x-ray films of the chest per year. Others
estimate that a cigarette addict may get exposed annually to a dose of
radiation, equivalent to 22,000 chest x-ray examinations. The dose
rate depends on the radioactive content of the tobacco, the puff size
and the frequency and number of cigarettes smoked. Scientists knew
that ionising radiation could cause cancer. In 1990, the then US
Surgeon General C.Everett Koop declared on US national television that
radioactivity in cigarette accounts for at least 90% of all smoking
related cancers. Dr Ravenholt, former Director of World Health
Surveys at the US Centers for Disease Control, stated that Americans
receive more radiation from tobacco smoke than from any other source.
American smokers smoke on average 11,000 cigarettes annually (nearly
11 kg of tobacco!). Many Indians are not far behind! Dr Ravenholt
showed that pollutants in cigarettes cause cancer in 14 different
tissues such as buccal cavity, pharynx, stomach, kidney, bladder, etc.
His observations came from the study of smokers among war veterans
over 16 years. In 1998, Attorney Amos Hausner claimed $8 billion from
one Israeli and six US tobacco companies for allegedly poisoning and
possibly irradiating Israelis with cigarettes. The defendant companies
knew all along that tobacco and smoke contained radioactivity, he
argued. They also knew how to reduce radioactivity levels in tobacco;
but did not do it, as the process was expensive. The case is yet to
come up for hearing. Scientists found high concentrations of Po-210
in certain regions of the lungs in seven out of the 37 smokers
studied. Lung cancers developed in these regions. Another group of
scientists instilled Po-210 in various amounts down to less than
one-fifth of that inhaled by heavy cigarette smokers during 25 years.
They could induce lung tumours in laboratory animals. Also, Po-210 is
the only pollutant in cigarette smoke that has produced cancers by
itself in laboratory animals by inhalation. Lung cancer rates in the
USA increased almost 10 fold between 1938 and 1956. The polonium
levels in American tobacco also tripled from 1938 to 1960. Lung cancer
rates showed increasing trend in women as in men though ladies
generally use filtered cigarettes. These remove benzopyrene and
nitrosamine, two well-known cancer inducing compounds. But cigarette
filters are not effective against Po-210 and Pb -210. Polonium
melts at 500°C. At 900°C, polonium and lead volatilises in
cigarettes. Ten percent of Pb-210 and 20 per cent of Po-210 contained
in cigarettes enter the smoker’s lung through the main smoke stream;
remaining 90 per cent of Pb-210 and 80 per cent of Po-210 remain in
the ambient air for the passive neighbours to inhale! Lighted cigarettes produce
Po-210 and insoluble Pb-210 in the main stream. Smokers inhale them
deep into their lungs. The airways branch into narrower and narrower
passageways. While smokers smoke cigarette after cigarette, the
particles of smoke bearing radioactive residues get deposited at these
branches. These hotspots deliver high radiation doses. Most lung
cancers are formed in these regions. Po-210 being soluble gets
removed from the inner linings of the lung. Blood circulating in the
lung absorbs it partly and carries it to every tissue and cell in the
body. Alpha particles from Po-210 cause mutations in the cell. Many of
these cells will die. But a few partly damaged cells may survive and
multiply uncontrollably without any rules causing cancer. Scientists
have separated Po-210 from tobacco smoke, deeper inner linings of the
lung and also from blood and urine of smokers. Smokers’ urine
contains six times more polonium than non-smokers’ do. Non
radioactive cancer-inducing agents are not found in the urine of even
heavy smokers. In 1982, hundreds of smokers stopped smoking after
reading a single paper in a medical journal. My article is based on
the knowledge accumulated since then. After nearly four decades of
study, Richard Doll, an eminent British epidemiologist at the Imperial
Cancer Research Fund Cancer Studies Unit at Oxford, declared thus:
"It now seems that about half of all cigarette smokers will
eventually be killed of their habit". I hope that this article in
The Tribune will persuade at least a few hundred smokers to quit! |
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Stem cell research on slow track Stem
cell research, which many scientists say will someday transform
medicine and free patients of incurable diseases such as diabetes and
Parkinson’s, has been moved to a slow track by U.S. politics,
experts have said. It will probably take a breakthrough in another
country to change the minds of U.S. politicians who now associate the
research with the debate over abortion, researchers glumly
predicted. "It will be the successful treatment of a disease
like Parkinson’s abroad," William Haseltine, chairman and chief
executive officer of Maryland-based biotechnology company Human Genome
Sciences Inc., told reporters at a conference on the field, called
regenerative medicine. Stem cell research is a broad but preliminary
field based on the discovery of master cells that can give rise to
various cells of the body. Most adult tissue and blood contain small
numbers of stem cells but the more controversial source is from very
early embryos, whose cells can become any kind of cell. Scientists
consider both routes promising. Researchers who pursue embryonic stem
cell work believe it would one day be possible to take a small plug of
skin from a patient and grow new brain cells, new heart muscle or even
a new organ such as a kidney. It would do away with the need for organ
donations and be a way to treat now-incurable diseases. But the
approach requires the use of a human egg and the production of a very
early human embryo. Opponents say this involves taking a human life.
Reuters |
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NEW PRODUCTS & DISCOVERIES Credit-card torch Created
by Iain Sinclair, this cool Eon torch transcends conventional pocket
light sources. Solid state and
ultra bright light emitting diodes are combined with special
innovative circuitry, to produce a pure and penetrating beam of light
of ultra high efficiency. This efficiency means you may never need to
buy another torch ever again. Very little power is consumed, so you
are unlikely ever to need to change the batteries. All this in a cool
looking ice blue exterior, as convenient as a credit card.
Ideas from
animals A consultancy firm
plans to sell ideas gleaned from the study of animal behaviour to
corporate clients on the promise that "animals and businesses
face many of the same problems". Alex Kacelnik of the University of Oxford founded the
Oxford Risk Research and Analysis (ORRA) last month with two other
zoologists, John Krebs, chair of the UK Food Standards Agency, and Ed
Mitchell. "A petroleum company forages for oil in much the same
way as a starling might forage for worms," the science journal
"Nature" has quoted him as saying. The basic choice they
face, he points out, is whether to stay in a field that is productive
but in decline, or to move on and take a chance elsewhere. Kacelnik’s
work on starlings has led him to believe that humans and other animals
approach risk in similar ways. He now plans to apply his models of how
animals cope with uncertainty through the consultancy firm. UNI
Diamonds
time capsules Much more
than jewels, diamonds provide distinctive signatures of earth’s
atmosphere as it existed three billion years ago, according to new
research. Scientists have proved that diamonds can be the
"natural time capsules", preserving information about the
cycling of sulphur between the earth’s crust, atmosphere and the
mantle back to three billion years. The study was funded by the
national Science Foundation, NASA’s Astrobiology Institute and the
American Chemical Society, and conducted by a team of scientists from
the Universities of Maryland and California at San Diego and Los
Angeles respectively. are valuable crystals through which geologists
and atmospheric chemists can peer to gain insights into the earth’s
atmosphere as it existed billion of years ago," said Mark
Thiemens, Dean of the Division of Physical Sciences at the University
of California, San Diego (USCD). UNI
Satellite
images copyright India has
successfully developed a novel technique for copywriting satellite
images. This new method called
"digital watermarking technique" can identify a specific
portion of satellite images as region of special interest and then
applies the process maintaining the quality of the image. The region
is elected keeping in view aspects like natural resources, commercial
uses, defence security and other, fileds of strategic importance. This
was disclosed by Mr Yogesh Chauhan of IIT Kanpur at the Indian
Conference on Computer vision, Graphics and Image processing at ISRO
Ahmedabad. The technological breakthrough is a result of year-long
research. Mr Chauhan claimed that none of the existing techniques is
region selective and suitable for applying to satellite images due to
their special characteristics and requirements. Digital Image
Watermarking is a method of identifying information in an image, in
such a manner that it cannot be easily removed. A watermark is used
for ownership protection, copy-control, authentication and to specify
the intended recipient and the date of transmission. UNI
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SCIENCE & TECHNOLOGY CROSSWORD
Clues
Across: 1. A class of very powerful chemicals preventing growth
of disease bacteria. 9. An unit of length used in measurement of
wavelength of light and inter-molecular distances. 10. These gases are chemically
inactive. 11. An Indian undertaking engaged in Gold production. 13. These
acids link together into polypeptide chains to form proteins. 15. Smallest
portion of an element which can take part in chemical reactions. 17. Symbol
for Beryllium. 18. Large cartilage of larynx projection which in
man forms Adam’s apple. 20. An analyser for ISDN measurements. 21. Symbol for
Molybdenum. 22. An electronic machine used to test sophisticated equipment
(abbr.) 24. A term used in medical science for pills taken orally. 25. Woody
plant smaller than tree. 27. A society that promotes general advancement of
illuminating engineering. 28. Symbol for Thulium. 29. Layer of Cartilage
between vertebrae. 30. Symbol for Einsteinium. Down: 1. The surface
obtained by rotating a parabola about its axis of symmetry. 2. A class of
substances having composition similar to glass with addition of stannic
oxide. 3. An institute that conducts research and training in Geo-physics.
(abbr.) 4. Of equal entropy. 5. An electronic machine used to carry Tomo-graphy
on patients. 6. Institute engaged in research & training in reproduction
biology. (abbr.) 7. These are used to carry calculations when the calculator
is not available. 8. Symbol for Nickel. 12. Part of body on both sides of
spine between false ribs and hip bones. 14. SI unit of resistance. 16. A
therapy promoted by WHO which combines more than one drug to cure leprosy. 19.
Grayish yellow fungous substances got from fermenting malt liquors. 21. Small
herbaceous cryptogram growing in crowded masses. 23. Short for engineer. 26.
…bar is a bare conductor used to carry heavy current. Solution
to last week’s
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Co2 shadow on plant growth New research in California has found that when other elements linked to global climate change are added to the environment of plants, carbon dioxide actually may act as a drag on growth. The study mimicked the conditions expected to result from global warming. It found that the effects of carbon dioxide, which plants use to produce food, can be either good or bad, depending on other elements of the environment. AP
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Shaw, Mitchell and Dorling of the University of Bristol
showed that a cigarette reduces one’s life by 11 minutes! (British
Medical Journal, January 1, 2000). This "frightening
statistic" attracted 13 responses in the next two weeks. Dr
Dorling declared that he is a 20-cigarettes-a-day smoker.
"Cigarette smoke contains radioactive fumes". I warned the
readers of the Journal. I wished to wean away Dorling and other
smokers from smoking! I have received no feedback yet.
