The World Health Organisation now has its little list of the things that cause cancer. The Mail helpfully lists them all. Some are obvious: it should come as no great surprise that ionising radiation from the breakdown of radioactive elements is cancer causing. Others are a great deal more controversial: the inclusion of silica for example. It's entirely true that very fine particles can, if they invade the lungs sufficiently, cause cancer. However, simply listing "sand" as carcinogenic makes Brighton off limits: even while the sort of Greens who live in Brighton insist that we must not frack for gas because it uses that carcinogenic sand.
Similarly, the listing of beryllium is not quite right: it is the dust of it, and more specifically of the oxide and or metal, that can cause berylliosis (a horrible disease, akin to mesothelioma from asbestos exposure).
It's also true that certain smokeless tobacco products do cause cancer: yet things like snus seem to reduce overall cancer rates by reducing the amount smoked. And it would be wonderful to point out that yes, it's true that gallium arsenide is cancer causing, but that's the arsenic in it, not the little chip made of it that sits in the middle of every mobile phone.
However, what confuses us is that the list does not include the one greatest cancer risk that we all face: long life. That we are all mortal, a couple of biblical exceptions aside according to the stories, is a fact of our existence. So thus not dying of smallpox, plague, starvation, rheumatic fever, toothache, measles or idiot wars, as all too many of our forbears did, is thus a cancer risk. Because if we don't die of them we'll survive long enough to get some form of cancer or another.
At which point we rather find ourselves wondering, as with the possibly allegorical little girl who asked this of Gladstone, "Mummy, what is the World Health Organisation for?"