Did you know that the phrase "mad as a hatter" comes from the use mercury in millinery? And that burning coal is the source of most mercury pollution? And that red mercury, a feared and much-sought ingredient of nuclear weapons, probably doesn't exist? Find out the truth about mercury, aka quicksilver, aka hydrargyrum, the only metallic element that's liquid at normal temperature and pressure.

Speaking of hoaxes, you may also have seen articles circulating on social media claiming "Scientists blow the lid on cancer & sunscreen myth". We bust the myth of this myth: the original article, published on Natural News, is based on a Swedish study published in May 2014, which highlights the need for people in Scandinavia to get enough vitamin D. At the same time though it confirms the link between sun exposure and melanoma, and actually says the rules are different in Australia.

The moral of the story? Follow the Cancer Council's SunSmart guidelines (which take vitamin D into account) and always check sources for scientific claims.