The slur against Carson is a myth that got started in the last couple of decades by anti-regulatory think tanks as a way to attack one of the foundations of the modern environmental movement. It's complete nonsense because 1) DDT spraying is still considered a legitimate method of mosquito (i.e. malaria) control, which was never the main problem anyway - widespread agricultural use was what led to "Silent Spring", and 2) DDT resistance eventually limited its effectiveness even for mosquito control. Read "Merchants of Doubt" if you want the gory details.