In this week's episode we speak with the author of a new book, Processed, about the downside of sandwich ham and salami, fried bacon, hot dogs, pepperoni pizzas and the like. Speaking with GW deputy editor Greg Callaghan, Morris-Marr explains how a raft of scientific papers link the nitrites used in many processed meats to improve flavour and eliminate bacteria, with cancer. She explores, too, why so many of us ignore such warnings.