Re: Elevated gross alpha background concentrations

[LIPTONW@dteenergy.com]

A good place to start is NCRP Report 50, "Environmental Radiation 
Measurements".  (IMHO this is the all time best NCRP report.  I had the 
privilege of working with Jake Sedlet, one of the authors.  To Jake and all 
the others - a big "attaboy".)  The section on "Radionuclides in Man's 
Environment" - "General Distribution Patterns", pp. 16ff, includes
statements, 
beginning on page 19:  "The radon content of ground-level air varies 
considerably with location and time...Both short-term measurements and 
long-term measurements are affected by time variations of Rn-222 and its 
daughters in the near-ground air. ... Significant diurnal and seasonal 
variations of Rn-222 concentrations are observed and can be mostly explained 
by changes in atmospheric stability conditions..."  There are references for 
this which may also be helpful. 
 
Regarding the potential effect of a coal burner, NCRP 95, "Radiation
Exposure 
of the U.S. Population From Consumer Products and Miscellaneous Sources", is
a 
good place to start.  The section on "Combustible Fuels", pp. 32ff provides 
data and references.  (This is also an excellent report; no invidious 
comparison is intended.) The impact of these emissions would also be
affected 
by atmospheric conditions. 
 
The opinions expressed are strictly mine. 
It's not about dose, it's about trust. 
 
Bill Lipton 
liptonw@dteenergy.com                                                       
  
                                                                            
  
                                                                            
  
                                                    
 
You wrote: 
 
     > 
     >I am an environmental HP at the Weldon Spring Site Remedial Action  
     >Project.  My group measures airborne gross alpha concentration as an  
     >indicator of environmental impacts from cleanup activities at our site
 
     >(the site contains isotopes of uranium, radium, and thorium).  Since  
     >about the middle of August I've been seeing elevated weekly gross  
     >alpha concentrations pretty much across the board, including at the  
     >background station which is 12 miles away. (Since our sources are at  
     >ground level, we do not expect that anything from our site could get  
     >that far.) Results are obtained on a weekly basis, and now we've seen  
     >4 weeks in a row with higher than normal readings.  "Elevated" means ~
 
     >2.4E-15 uCi/ml vs. a long-term average of 1.2E-15 uCi/ml, or  
     >approximately double.  Has anyone else seen this phenomenon,  
     >particularly if you are in the Midwest?  We have some theories, all of
 
     >which are going to be difficult to prove.  One is that the coal-fired  
     >plant 15 miles down the river might be affecting our results.  Does  
     >anyone have any insight on the effects of coal burning on natural  
     >airborne radioactivity levels? 
      
    >Thanks, 
     >Elizabeth Algutifan 
     >Jacobs Engineering Group 
     >7295 Hwy. 94 S 
     >St. Charles, MO  63304 
     >(314) 441-8086, ext. 3514
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