Polonium cancer

Little, J. B., A. R. Kennedy and R. B. McGandy, Lung cancer induced in hamsters by low-doses of alpha radiation from polonium-210, Science 188 737-738 (1975). 

Cigarette smoke contains a minute amount of polonium, along with many other carcinogenic chemicals, many of which can cause lung cancer. Over one hundred trace elements and compounds have been identified in cigarette smoke besides polonium. Some examples are nicotine, cresol, carbon monoxide, pyridine, and the carcinogenic compound benzopyrene. 

Radon is another example of a very curious and toxic compound that many of us regularly inhale, hopefully in small amounts. For those regularly exposed to radon, there is an increased risk for lung cancer and, for those that smoke, radon exposure results in a three-fold increase in the incidence of lung cancer. In the United States it is estimated that indoor radon exposure causes between 7000 and 30,000 lung cancer-related deaths each year, second only to tobacco smoking. Radon-222 is a colorless and odorless radioactive gas that results from the decay of radium-226, which is widely distributed in the earth s crust. Radon decays with a half-life of 3.8 days into solid particles of polonium. It is actually the breakdown of... 

Little, J.B., McGrandy, R.B., and Kennedy, A.R. (1978). Intaactions between Polonium 210 irradiation, benzo[a]pyrene, arid 0.9% NaCl solution instillations in the induction of experimental lung cancer, Cancer Res. 38,1929. 

The compounds of the particle phase are collectively called tar, or total particulate matter (TPM). Tar is the oily residue left behind when moisture evaporates from burned tobacco. It contains thousands of compounds, including cancer-causing aromatic amines, nitro-samines, and polycyclic aromatic hydrocarbons that are present in both smoking and smokeless tobacco. Other harmful constituents include radioactive lead and polonium as well as arsenic, among others. 

Marie Curie discovered the element polonium, Po, in 1898. She named polonium after Poland, her homeland. Curie won two Nobel Prizes, one in Physics (1903) for sharing in the discovery of radioactivity, and one in Chemistry (1911) for the discovery of radium, which has been used to treat cancer. Radium-226 undergoes alpha decay to yield radon-222. 

Most cancers from radon were produced by radon daughter decay products (polonium - 3 isotopes bismuth - 1 isotope and lead - 3 isotopes). ERR (excessive relative risks) of cancers varied, ranging from 0.002 to 0.08 per working level months (WLM) of 170 h of exposure. One WLM is about 200 pCi per liter in a home and 300 pCi per liter in an imdergroimd mine. Relative risk increases from 1 to 10 at 2,500 WLM and 16 at twice that exposure level (5,000 WLM) in the Colorado cohort (Harley, 2008). 

Polonium was discovered in 1898 by Marie and Pierre Curie in their search for the sources of radioactivity in pitchblende. Polonium has 27 isotopes and is highly toxic and very radioactive. It has been suggested that the isotope 210Po, a natural contaminant of tobacco and an a-particle producer (see Section 21.1), might be at least partly responsible for the incidence of cancer in smokers. 

Natural radioactivity. Discovery by Becquerel, Isolation of polonium and radium from pitchblende, by the Curies. Alpha rays, beta rays, gamma rays. Effect of a magnetic field on these rays. Use of radium and other radioactive elements in the treatment of cancer. 

In 1903, the Curies shared the Nobel Prize in Physics for their work with radioactivity. Pierre died in an accident in 1906, and Marie continued her research. She won the 1911 Nobel Prize in Chemistry for discovering polonium and radium. Marie Curie died of a type of cancer called leukemia. Exposure to radioactivity caused her cancer. 

These radioactive isotopes are solids that can collect on dust. When the dust is inhaled, the radioactive solids remain in the lungs. High-energy alpha particles from the polonium and lead damage the DNA of lung cells, sometimes causing cancer. 

Polonium whole body Cancer 9.1x10 8.3x10"... 

Bogden, J.D., F.W. Kemp, M. Bnse, I.S. Thind, D.B. Louria, J. Forgacs, E. Lians, and I.M. Terrones Composition of tobaccos from countries with high and low incidences of lung cancer. I. Selenium, polonium-210, tar, and nicotine J. Natl. Cancer Inst. 66 (1981) 27-31. 

Institute of Cancer Research Polonium ( Po) in tobacco smoke and in the environment See Tob. Bibliograph. 

Radford, E.P. Jr Polonium-210 alpha radiation as a cancer initiator in tobacco smoke Radiation Res. 59 (1974) 3081. 

The uranium decay series provides the most important isotopes of elements radium, radon, and polonium, which can be isolated in the processing of uranium minerals. Each ton of uranium is associated with 0.340 g of Ra. Freshly isolated Ra reaches radioactive equilibrium with its decay products to Pb in about two weeks (see Fig. 1.2). Many of these products emit energetic y-rays, which resulted in the use of Ra as a y-source in medical treatment of cancer (radiation therapy). However, the medical importance of radium has diminished greatly since the introduction of other radiation sources, and presently the largest use of radium is as small neutron sources (see Table 12.2). 

Marie Curie s Radium Institute at the east end of the Rue Pierre Curie in the Latin Quarter, built just before the war with funds from the French government and the Pasteur Foundation, had the advantage in any studies that required polonium. Radon gas decays over time to three only mildly radioactive isotopes lead 210, bismuth 210 and polonium 210, which thus become available for chemical separation. Medical doctors throughout the world then used radon sealed into glass ampules— seeds —for cancer treatment. When the radon decayed, which it did in a matter of days, the seeds no longer served. Many physicians sent them on to Paris as a tribute to the woman who discovered radium. They accumulated to the world s largest source of polonium. 

Because radon has such a short half-life and because alpha particles have a high RBE, inhaled radon is considered a probable cause of lung cancer. Even worse than the radon, however, is the decay product because polonium-218 is an alpha-emitting chemically active element that has an even shorter half-life (3.11 min) than radon-222 ... 

When a person inhales radon, therefore, atoms of polonium-218 can become trapped in the lungs, where they bathe the delicate tissue with harmful alpha radiation. The resulting damage is estimated to contribute to 10% of all lung cancer deaths in the United... 

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