 The documentary discusses how US government tobacco interests prevented this evidence from coming to surface since tobacco was such an important US export.Cancer Wars delved into the pioneering work of Rachel Carson, whose book "Silent Spring" radically changed the world's thinking about chemicals and their effects on human health and the environment.Other episodes in this series discussed various topics ranging from the history of the advances in cancer therapy to the influence of Margaret Thatcher's neoliberal policies which cut funding to Anti-smoking campaigns in Britain because of interests in protecting British tobacco companies.