[ RadSafe ] IAEA DACs

JGinniver at aol.com JGinniver at aol.com
Wed Feb 8 15:58:24 CST 2006


In a message dated 08/02/2006 19:27:08 GMT Standard Time, james at bovik.org  
writes:

I note  with sadness that those derived air concentration exposure 
limits are  based only on radiotoxicity, completely ignoring the 
chemical toxicity of  the isotopes involved; many of which pose 
a far greater chemical than  radiological hazard.  There isn't even 
a footnote or a disclaimer  anywhere in the report pointing out 
this problem.

James, I think you have missed the point.  These are only claimed to  be 
Radiological Protection Standards (Occupational Exposure due to Intakes of  
Radionuclides).  This document should have to provide a disclaimer as it  states up 
front what it is interested in.


That  kind of negligence is inexcusable.  It leads to a false sense 
of  security based on radiological safety alone, when chemical 
toxicity poses  the real danger. 
There are separate standards and limits on chemical toxicity.  I'm not  100% 
certain for the US, as it's not my normal place of work, but I believe  these 
are addressed by OSHA and their occupational exposure standards.   What I have 
always found interesting is the comparison between protection from  the 
harmful effects of chemicals where you have 8 hour Time Weighted Averages  (TWA) 
and Short Term Exposure Limits (STEL) and radioactivity. It's been my  
experience that the TWA and STEL are regarded as limits below which  exposure is 
acceptable.  I have never encountered anyone that recommends an  ALARA approach to 
exposure to chemicals.

At least  the NRC's DACs make an 
attempt to limit kidney-damaging levels of a few  isotopes, 
although the NRC has completely ignored substantial  reproductive, 
developmental, immuniological, and neuro-toxicities,  too.
To my dismay, I can't clearly recall some of the clarification I have  
received in the past from the list on the role of the NRC, however I do believe  
that employers in the US are required to comply with the OSHA standards.   If 
this is the case and reproductive, developmental, immuniological and  
neurotoxicities are address by these then it doesn't make sense (to me at  least) for the 
NRC to regulate these.  The last thing anyone needs is for  two organisations 
to regulate the same areas.  It can lead to conflicting  standards and 
confusion.
 



What will the next generation of health professionals think  about 
this sad state of affairs?  
Who  will be the leader in correcting this problem?




Is there a problem?  If the exposure standards for radionuclides are  
reviewed, set and regulated by individuals who have specialist knowledge and  
experience radiation protection, and standards for chemical hazards are  reviewed, 
set and regulated by individuals who have the specialist knowledge and  
experience with these issues isn't that the correct approach.  IMHO it  would be far 
worse if we tried to get radiological protection specialists to  regulate 
chemical hazards.
 
I look forward to your reply warmest regards,
Julian
 
p.s. Perhaps the ideal is for one organistation to regulate all possible  
sources of exposure that may lead to deleterious health effects.  This way  
chemical, non-ionising radiation, ionising radiation, UV, infra red and  biological 
hazards could be combined into a single exposure standard.   Unfortunately 
it's not to be and consequently people will have to perform  adequate risk 
assessments for all of the possible sources of exposure to ensure  the overall risk 
is limited to a level that society finds broadly  acceptable.



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