Alpha-emitters in the workplace

A number of groups of workers have been exposed to Į-particle-emitting radionuclides, of
particular importance being the radium dial painters, underground hard rock miners exposed to radon
and its decay products, and, more recently, plutonium workers. These occupationally exposed groups
are of interest because they allow the direct study of the health effects of exposure to alpha-emitters
and the comparison with the level of such effects present among groups exposed predominantly to
external sources of low-LET radiation. Hence, these worker groups are important in testing the
assumptions that underlie radiological protection. The radium dial painters experienced a pronounced
excess of bone cancers and cancers of the paranasal sinuses and mastoid air cells, while a clear radonrelated excess of lung cancer is present among the underground hard rock miners. There is little
evidence for a radiation-related excess risk of other cancers being present in these groups. A number
of groups of workers have been exposed to plutonium in the weapons and civil nuclear industries. The
group of plutonium workers at the Mayak nuclear facility in Russia is especially important because of
the large numbers exposed to high levels. The Mayak workers have pronounced plutonium-related
excess risks of lung, liver and bone cancers, and possibly of other solid tumours, but not leukaemia.
Where organ-specific internal doses have been derived, which is presently confined to the lung, risk
coefficients are compatible with predictions based on standard models. However, further
investigations of the Mayak workforce are required before reliable risk estimates for plutonium
exposure may be derived, but this group of workers has the potential of generating definitive risk
coefficients for health effects arising from exposure to plutonium.