actually, it was to cover up what the above ground nuclear testing had done. and 60 years later, those particles are randomly being tossed about the planet, awaiting a chance encounter with some poor soul with spf 50 sunscreen on so the radioactive particle attaches to the skin of the individual giving them the very skin cancer they are trying to avoid and being exacerbated by inadequate sun for vitamin D production and an almost complete lack of Iodine in the body.