Radiation
Alpha radiation 2 protons and 2 neutrons, eg plutonium, radon; α radiation travels 15 cm in air and is stopped by a piece of paper; proven role in soft tissue malignancy–see Radium Dial company, relationship with epithelial malignancy is uncertain; it is present in cigarette smoke and may have an additive effect to the known carcinogenic effect of tar; emitted by radium, thorium, uranium.
Beta radiation Electrons, eg strontium-90, tritium–3H; β radiation travels at the speed of light, is stopped by wood and thin metals and is carcinogenic to skin
Gamma radiation Gamma photon A quantum of electromagnetic radiation of ≤ 1 nm, which is generated by unstable nuclei eg 60Co; γ radiation is stopped by several feet of heavy concrete or 10-40 cm of lead and is linked to cancer, inducing mutations at the glycophorin A locus in survivors of atomic blasts; 183/105 excess deaths in survivors of the Hiroshima and Nagasaki blasts, with a 13-fold ↑ in non-lymphocytic leukemia–peaking at 6 yrs post-blast, thyroid nodules and tumors–peaking at 15-20 years post-blast and multiple myeloma 6-fold ↑–peaking 30 yrs post-blast