Why are lung cancer rates rising among young, fit women who have never smoked?

According to the Center for Disease Control and Prevention, 20% of new cases in the United States are in people who never smoked, with young women making up the majority of the cases. Experts believe the rise in non-smoking cases is largely driven by radon exposure, air pollution, and genetic mutations. We speak with Dr Pinar Uysal, Reader in Molecular Biology at the University of Westminster.