This week, scientists recreate hair follicles, we uncover a means of making hydrogen in a hurry, hear about a stealthy way to destroy cancer and find out why a dose of herpes could be good for you. Also, John Grattan describes the biggest atmospheric pollution event in history, we discover with Rod Jones the role of water in the greenhouse effect, and Jonathan Shanklin tell us the 'hole' story of the ozone layer. Plus, in Kitchen Science, we make a cloud in a bottle! Like this podcast? Please help us by supporting the Naked Scientists)