[ RadSafe ] Re: Indoor Radon

[Philippe Duport]

Patrick,

I am the co-author, with John Johnson of the recent (Dec 2004) review of Rn risk in U mines made for Radiation Protection Bureau (Health Canada).  I would like to add to what John Johnson says that, since we are looking at lung cancer, what counts is the dose (of whatever carcinogen) to the lung.  In that regard, LUNG doses from radon decay products, gamma radiation and airborne ore dust are of comparable magnitude and that, in low grade U mines, radon decay products contribute less than half the total radiation dose - a systematic bias in epid studies (see P Duport, Radiation Protection Dosimetry Vol. 98, no. 3. pp. 329-338, 2002). The relative contribution of radon decay products to the total radiation dose to the lung is much less in high grade mines.   Also, if we accept the EPA position that cancer risks from multiple carcinogens are additive, the lung cancer risk attributable to radon decay products alone must be the difference between the overall risk observed in a population minus the sum of the risks due to all other carcinogens.  To fail to accept that is to admit, implicitly, that the risk is not linear with dose and that risks are not additive.

Please tell me if the reasoning is wrong...  I am not infallible.

regards,

Philippe Duport
  ----- Original Message ----- 
  From: John R Johnson 
  To: Patrick Glennon ; Radsafe 
  Cc: Daniel F. Buksak ; Raymond Ilson ; Philippe Duport(OU) ; David Morley 
  Sent: Thursday, May 19, 2005 2:13 PM
  Subject: Indoor Radon


  Patrick

  I have looked at your message in more detail since my to response Otto Raabe's mail yesterday. I would also like take part in a "flame free" dialogue on Indoor Radon.

  We have just finished a review of lung cancer in miners from radon for Health Canada (where Chen works) and concluded that the lung cancers caused by exposure to silica and diesel exhaust have not been taken into account in the extrapolation to "indoor" radon, and therefore the risk in houses is less than is usually calculated.

  FYI, there will be a "Heath Canada Radon Group" meeting (June 19) and 2 Radon Sessions (June 22) at the CRPA AGM in Winnipeg (see http://www.crpa-acrp.ca/en/conference). Winnipeg is a good place for these sessions because it had high indoor radon in the "cross Canada survey" that was done before the current 800 Bq/m^3 guideline was established in 1988. 

  I will be at the AGM and look forward to attending these sessions and discussions. 


  Perhaps I'll see you there!

  John 
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