What are the medical risks and benefits of silver? Is what I call a smell the same experience for you? And why do some things smell appealing, but not others? Does engine oil have a best-before date? And why do metal insulin needles have a use-by date? What makes body odours attractive? Is the inside of a banana sterile? And how do scientists find the medical properties of plants? Like this podcast? Please help us by supporting the Naked Scientists