This week we're bringing you the very best bits from the BA Festival of Science in York. We discover a chewing gum that dissolves in the wash but still keeps your breath fresh, get some good news about cancer and find out why jogging may not be good for heart patient recovery if it's near a busy road. Also, Chris risks his health to find out about plague control in 17th Century York, and chocolate may be nicer than it is naughty, as Roger Corder explains how it could be good for your health. Out and about in the festival, Meera explores the psychology of commuter cooperation during the 2005... Like this podcast? Please help us by supporting the Naked Scientists