Re: Uranium, radium in Groundwater/Granite

[SAFarberMSPH@cs.com]

In a message dated 1/25/01 2:08:02 PM Pacific Standard Time, 
Jim_Hardeman@mail.dnr.state.ga.us writes:


> My staff and I, along with some rad folks from EPA, went up to his house ... 
> and boy, did WE ever have an interesting find ... the radiation level about 
> 1 meter from his water heater was around 2-3 mR/hr ... about 100 uR/hr 
> above his toilet ... similar levels anywhere there was water.


Some years ago the RI Dept. of Health reported at a NE Chapter HPS meeting 
the results of a radiation survey near a water softener at a nursing home. 
Measurements near the water softener documented direct gamma doses of 100 
mR/hour as I recall [not sure of the distance of measurement].  The buildup 
of salts in the water softener had created quite an unusual localized source.

The state of RI has some very high U content granite and has a very high 
percentage of its land area underlain by granite. Granite used to be mined at 
numerous locations in RI. I once conducted a background radiation survey 
around Westerly, RI where a large number of homes and government buildings 
are built of locally mined granite. The typical gamma dose rate measured with 
a high pressure ionization chamber about 1 foot from a wall or column [of a 
government building] is about 50 uR/hour [including all terrestrial/cosmic 
components], or a bit more than 40 uR/hour net gamma from the granite.

Stewart Farber
Consulting Scientist
Public Health Sciences
email: SAFarberMSPH@cs.com