Rachel Carson’s 1962 book Silent Spring has probably done more than any other to raise concerns about the damage that uncontrolled use of chemicals can cause to the natural world. Carson imagined a ‘silent spring’ in a world where birds no longer sang, killed off by indiscriminate spraying of pesticides. Her plea for caution when using insecticides led to major changes in government regulation of agrochemicals both in the United States and elsewhere. So who was Rachel Carson? How did this scientist with a passionate interest in marine biology turn first into a best-selling author and then into an environmental campaigner? And - six decades on - have the warnings of Silent Spring been heeded? Bridget Kendall is joined by Dr. Sabine Clarke, Senior Lecturer in Modern History at University of York with a particular interest in the history of synthetic insecticides; Michelle Ferrari, an award-winning film maker who directed a documentary about Rachel Carson's life for the American public broadcaster PBS; and Professor David Kinkela, an environmental historian and chair of the Department of History at Fredonia, State University of New York whose books include 'DDT and the American Century'. The reader is Ina Marie Smith. (Photo: Airplane dusting a field with DDT. Credit: Bettmann/Getty Images)