Ra-226 In Luminous Paint -Reply

[FRAMEP@ORAU.GOV]

Dale Thomas wrote:
     
>What is the concentration (activities/gram) of Ra-226 in paint that was
>used watch/instrument dials/gauges.
     
Robley Evans states that the mixture is about 1 part radioactive material
per 40,000 paint, i.e. 25 ug radium per gram of paint.  See Health Physics
38(June) 1980 pp 899 -905. "Radium Poisoning: A Review of the
Knowledge". Evans gets this value from Hoffman's "Radium Necrosis" in
JAMA 85(1)p 961, 1925.  

The preceeding figure applied to commercial watch
production. Ed Landa points out that substantially higher radium
concentrations were used by the military. Looking at Landa's numbers, it
would seem that the military concentrations were on the order of 4 to 10
times those in the commercial sector. See Ed Landa "Buried Treasure to
Buried Waste" Colorado School of Mines Quarterly 82(2) 1987.

Perhaps this helps get us in the right ballpark.

Best wishes

Paul Frame
Professional Training Programs
ORISE
framep@orau.gov