SCIENCE TRIBUNE Thursday, December 26, 2002, Chandigarh, India

Radioactivity in cigarettes
K.S. Parthasarathy
haw, 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.

Stem cell research on slow track
tem 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.



Radioactivity in cigarettes
K.S. Parthasarathy

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.

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!



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



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






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.


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 Crossword:



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