Path: alberta!quartz.ucs.ualberta.ca!unixg.ubc.ca!news.mic.ucla.edu!library.ucl a.edu!europa.eng.gtefsd.com!howland.reston.ans.net!math.ohio-state.edu!cis.ohio -state.edu!news.sei.cmu.edu!bb3.andrew.cmu.edu!andrew.cmu.edu!cr39+ From: Christopher B Reeve Newsgroups: alt.drugs Subject: Re: Fertilizing tobacco plants [was Re: Cigarettes radioactive?] Date: Sat, 19 Nov 1994 12:09:56 -0500 Organization: Carnegie Mellon, Pittsburgh, PA Lines: 181 Message-ID: NNTP-Posting-Host: po3.andrew.cmu.edu In-Reply-To: <3aka0l$nhp@scapa.cs.ualberta.ca> > [2] Ponte, Lowell. "Radioactivity: The New-Found Danger in > Cigarettes," Reader's Digest, March 1986, pp. 123-127. > ^^^^^^^^^^^^^^^^ > > ************> This is the only study which you quote which > has "radioctivity" and "cigarette OR tobacco" linked in the > title. > Its just not convincing me . . <***************** So, what you're saying, is that if I produce a lot of references that seem to look good, then you'll believe it? Surely it can't be that easy to convince you? Perhaps the _Reader's Digest_ isn't typically a place where one goes to find scientific articles, but it says the same thing all of the scientific articles articles are saying, but in better more understandable writing. You'd have to be a bio or chem major in order to fully evaluate what's going on in most of the scientific articles that have been written. Here, I'll give you a sample of what the scientists are saying (complete with plenty of sources): EXCERPTED MATERIAL FROM FTP SITES FOLLOWS: Winters-TH, Franza-JR, Radioactivity in Cigarette Smoke, New England Journal of Medicine, 1982; 306(6): 364-365 (reproduced w/o permission) To the Editor: During the 17 years since the Surgeon General's first report on smoking, intense research activity has been focused on the carcinogenic potential of the tar component of cigarette smoke. Only one definite chemical carcinogen -- benzopyrene -- has been found. Conspicuous because of its absence is research into the role of the radioactive component of cigarette smoke. The alpha emitters polonium-210 and lead-210 are highly con- centrated on tobacco trichomes and insoluble particles in cigarette smoke (1). The major source of the polonium is phosphate fertilizer, which is used in growing tobacco. The trichomes of the leaves con- centrate the polonium, which persists when tobacco is dried and processed. Levels of Po-210 were measured in cigarette smoke by Radford and Hunt (2) and in the bronchial epithelium of smokers and nonsmokers by Little et al. (3) After inhalation, ciliary action causes the insoluble radioactive particles to accumulate at the bifurcation of segmental bronchi, a common site of origin of bronchogenic carcinomas. In a person smoking 1 1/2 packs of cigarettes per day, the radia- tion dose to the bronchial epithelium in areas of bifurcation is 8000 mrem per year -- the equivalent of the dose to the skin from 300 x-ray films of the chest per year. This figure is comparable to total- body exposure to natural background radiation containing 80 mrem per year in someone living in the Boston area. It is a common practive to assume that the exposure received from a radiation source is distributed throughout a tissue. In this way, a high level of exposure in a localized region -- e.g. bronchial epithelium -- is averaged out over the entire tissue mass, suggest- ing a low level of exposure. However, alpha particles have a range of only 40 um in the body. A cell nucleus of 5 to 6 um that is traversed by a single alpha particle receives a dose of 1000 rems. Thus, although the total tissue dose might be considered negligible, cells close to an alpha source receive high doses. The Po-210 alpha activity of cigarette smoke may be a very effective carcinogen if a multiple mutation mechanism is involved. Radford and Hunt have determined that 75 per cent of the alpha activity of cigarette smoke enters the ambient air and is unab- sorbed by the smoker, (2) making it available for deposit in the lungs of others. Little et al. have measured levels of Po-210 in the lungs of nonsmokers that may not be accounted for on the basis of natural exposure to this isotope. The detrimental effects of tobacco smoke have been considerably underestimated, making it less likely that chemical carcinogens alone are responsible for the observed incidence of tobacco-related carcinoma. Alpha emitters in cigarette smoke result in appreciable radiation exposure to the bronchial epithelium of smokers and probably secondhand smokers. Alpha radiation is a possible etio- logic factor in tobacco-related carcinoma, and it deserves further study. Thomas H. Winters, M.D. Joseph R. Di Franza, M.D. University of Massachusetts Worcester, Ma 01605 Medical Center 1. Martell EA. Radioactivity of tobacco trichomes and insoluble cigarette smoke particles. Nature. 1974; 249:215-7. 2. Radford EP Jr, Hunt VR. Polonium-210: a volatile radioelement in cig- arettes. Science. 1964; 143:247-9 3. Little JB, Radford EP Jr, McCombs HL, Hunt VR. Distribution of po- lonium-210 in pulmonary tissues of cigarette smokers. N Engl J Med. 1965; 273:1343-51. Responses to this letter: NEJM 307(5):309-313. reproduced w/o permission To the Editor: In a letter in the Feb 11 issue, Winters and DiFranza (1) correctly point out that alpha radiation from polonium-210 is a possible causal factor in tobacco-related carcinoma, but they incorrectly state that ``inhaled'' Po210 is a factor and that research on this important possibility has been neglected. I will briefly review recent pertinent research. Radford and Hunt (2) first suggested that alpha radiation from Po210 in cigarette smoke may be important in the genesis of bronchial cancer. Little et al. (3) found surprisingly high concentrations of Po210 at single bronchial bifurcations in seven of 37 cigarette smokers. Holtzman and others (4 - 6) raised doubts about the validity of these observations because inhaled volatile Po210 is soluble and rapidly cleared. Subsequently, I determined (7) that lead-210 (a beta-emitting precursor of Po210) is highly concentrated in tobacco trichomes and that trichome combustion in burning cigarettes produces insoluble, Pb210-enriched particles in mainstream smoke. Thus, the high concentrations of Po210 observed at segmental bifurcations (4 - 6) can be explained by the persistence of insoluble, Pb210-enriched particles deposited at bifurcations and by the ingrowth of Po210 in these particles. (7,8) Radford and Martell (9) confirmed that the excess Po210 in the bronchial epithelium of smokers is accomplished by a larger excess of Pb210. Fleischer and Parungo (10) provided experimental evidence indicating that radon decay products and Pb210 are concentrated on trichome tips. Mechanisms of accumulation of Pb210 on tobacco trichomes are discussed by Martell and Poet. (11) Two recent studies (12,13) indicate that alpha radiation from inhaled indoor radon progeny may explain the incidence of lung cancer in nonsmokers. Martell and Sweder (14) report that indoor radon decay products that pass from the room air through burning cigarettes into mainstream smoke are present in large, insoluble smoke particles that are selectively deposited at bifurcations. Thus, the smoker receives alpha radiation at bronchial bifurcations from these three sources: from indoor radon progeny inhaled between cigarettes, from Po214 in mainstream smoke particles, and from Po210 that grows into Pb210 enriched particles that persist at bifurcations. I estimate that the cumulative alpha dose at the bifurcations of smokers who die of lung cancer is about 80rad (1600rem) -- a dose sufficient to induce malignant transformations by alpha interactions with basal cells. Edward A Martell, Ph.D. National Center for Atmospheric Research Boulder, CO 80307 1. Winters TH, DiFranza JR. Radioactivity in Cigarette Smoke. NEJM 1982 306:364-365 2. Radford EP, Hunt VR. Polonium-210: a volatile radioelement in cigarettes. Science. 1964; 143:247-249 3. Little JB, Radford EP, McCombs HL, Hunt VR. Distribution of polonium-210 in pulminary tissues of cigarette smokers. NEJM. 1965; 273:1343-1351 4. Holtzman RB, Ilcewicz FH. Lead-210 and polonium-210 in tissues of cigarette smokers. Science. 1966; 153:1259-1260 5. Little JB, Radford EP. Polonium-210 in bronchial epithelium of cigarette smokers. Science. 1967; 155:606 6. Holtzman RB. Polonium-210 in bronchial epithelium of cigarette smokers. Science. 1967; 155:607 7. Martell EA. Radioactivity in tobacco trichomes and insoluble cigarette smoke particles. Nature. 1974; 249:215-7 8. Martell EA. Tobacco radioactivity and cancer in smokers. Am Sci. 1975; 63:404-412 9. Radford EP, Martell EA. Polonium-210: lead-210 ratios as an index of residence times of insoluble particles from cigarette smoke in bronchial epithelium. In: Walton WH, ed. Inhaled particles, part 2. Oxford: Pergamon Press, 1977:567-580 10.Fleischer RL, Parungo FP. Aerosol particles on tobacco trichomes. Nature. 1974; 250:158-159 11.Martell EA, Poet SE. Radon Progeny on Biological Surfaces and their effects. In: Vohra KG, et al., eds. Proceedings, Bombay Symposium on Natural Radiation in the Environment. New Delhi: Wiley Eastern Ltd., 1982 12.Evans RD, Harley JH, Jacobi W, Mclean AS, Mills WA, Stewart CG. Estimate risk from environmental exposure to radon-222 and its decay products. Nature. 1981;290;98-100 13.Harley NH, Pasternack BS. A model for predicting lung cancer risks induced by environmental levels of radon daughters. Health Phys. 1981; 40:307-16. 14.Martell EA, Sweder KS. The roles of polonium isotopes in the etiology of lung cancer in cigarette smokers and uranium miners. In: Gomez M, ed. Proceedings of a symposium on radiation hazards in mining. New York: American Institute of Mining Engineers, 1982:383-389. -- "The ambition of every poor Mexican is to sell enough pot so that he can get rich enough to get drunk on alcohol." (Anonymous Mexican, from Lester Grinspoon, _Marihuana Reconsidered_, 214)