Cancer mortality in the USA and cosmic ray neutron dosage

The mortality rates for a number of common cancers are not distributed uniformly throughout the USA; rather there are significant differences geographically. The variation in the radiation dose from cosmic ray neutrons provides a framework which can describe the differences. These systematics have been in place for significantly more than fifty years. This investigation was prompted by the well established experimental fact that cosmic ray neutrons are a source of soft errors in silicon based microelectronics. The neutrons interact in the silicon, producing heavily ionizing secondaries, in particular alpha particles. Cosmic ray neutrons copiously produce alpha particles in the cells of the body, leading to an effective low dose, high LET, irradiation of cells which will be uniformly distributed internally throughout the body and its organs. While the interaction between alpha particles and cells is an active field of research, there seem to be enough unanswered questions to permit a provocative proposal of a role for cosmic rays in the genesis of human cancer.