She explains about Polonium's short half life and chemical/radiological characteristics and adds:
All of this — the low level of natural occurrence, the very targeted efficiency of the poison — tell you that it’s highly unlikely for anyone to accidentally receive a lethal dose of polonium-210.
But it is possible to give yourself a nasty little dose — and that’s by becoming a heavy smoker of cigarettes. There’s a detailed description of some of these risks at the website of Lenntech, a company that makes air and water filters. It cites among other things, data from the CDC that “Americans are exposed to more radiation from tobacco smoke than any other source.” It also notes that polonium-210 has been isolated from both the blood and urine of heavy smokers.
another article mentions other toxins in cigarettes.
but it gets worse, she says:
And when I read the FDA list of hazardous compounds in cigarette smoke and found not only polonium-210 (the radioactive element suspected in Arafat’s death) but two well-known isotopes of uranium best associated with nuclear reactors (uranium-235 and uranium-238), I thought – wow, how did I miss that?
As it turns out, there’s a real case to be made that I – and really all of us – missed this because the tobacco companies hid the information, that cigarette makers flagged the problem internally by 1960s and studied it in secret. The best evidence for that comes from the companies’ confidential documents, which were released in the 1998 Tobacco Master Settlement Agreement between four major companies – Philip Morris, R.J. Reynolds, Brown & Williamson and Lorillard – and attorney generals from 46 states.
An analysis of those documents by public health researchers at the University of California-Los Angeles was published last year in the journal, Nicotine and Tobacco Research. As that study (paywall) notes:
The documents show that the industry was well aware of the presence of a radioactive substance in tobacco as early as 1959. Furthermore, the industry was not only cognizant of the potential “cancerous growth” in the lungs of regular smokers but also did quantitative radiobiological calculations to estimate the long-term (25 years) lung radiation absorption dose (rad) of ionizing alpha particles emitted from the cigarette smoke.
This wasn’t the first study to note the corporate coverup; an earlier report in American Journal of Public Health reached the same conclusion. Still, let’s call the information an imperfectly kept secret (as so many are). In 1964, for instance, we find scientists from the Harvard School of Public Health reporting that they had discovered hot spots, fizzing with polonium-210, in the lungs of regular smokers. They published that finding in the highly visible New England Journal of Medicine in 1965, warning that “we believe 210Po may be an important factor in the initiation of bronchial carcinoma in humans”. It wasn’t, actually, that tobacco companies were entirely successful at hiding the radioactive nature of cigarettes; it was that the rest of us weren’t entirely successful at paying attention.
But, as the UCLA analysis points out, internal documents revealed something else. Not only did cigarette makers know about polonium-210 contamination of their product for decades – they knew how to fix it and chose not to. And to understand that, you need to know why tobacco plants become such little radiation factories.
and here is an article in Scientific American: