Re: Radon-Stirring the Pot

[epirad@mchsi.com]

Tom wrote: 



"Are glass-based radon detectors used for assessing home 

radon concentrations for mitigation purposes?"



Tom, I do not know of any place where they are used for 

mitigation purposes.   



Alavanja et al. have addressed the limitations of the MO-

I dosimetry, see:



Michael C. R. Alavanja, Jay H. Lubin, Judith A. 

Mahaffey, Ross C. Brownson, RE: "RESIDENTIAL RADON GAS 

EXPOSURE AND LUNG CANCER: THE IOWA RADON LUNG CANCER 

STUDY" Am. J. Epidemiol. 2000 152: 895-896.



Tom,  Alavanja attributes the higher odds ratios of the 

MO-II study to the improved dosimetry of the glass 

detector.  



Lagarde recently came the same conclusion:

J Expo Anal Environ Epidemiol 2002 Sep;12(5):344-54   

  

Glass-based radon-exposure assessment and lung cancer 

risk.



Lagarde F, Falk R, Almren K, Nyberg F, Svensson H, 

Pershagen G.



Institute of Environmental Medicine, Karolinska 

Institutet, Stockholm, Sweden.



Lung cancer risk estimation in relation to residential 

radon exposure remains uncertain, partly as a result of 

imprecision in air-based retrospective radon-exposure 

assessment in epidemiological studies. A recently 

developed methodology provides estimates for past radon 

concentrations and involves measurement of the surface 

activity of a glass object that has been in a subject's 

dwellings through the period for exposure assessment. 

Such glass measurements were performed for 110 lung 

cancer subjects, diagnosed 1985 to 1995, and for 231 

control subjects, recruited in a case-control study of 

residential radon and lung cancer among never-smokers in 

Sweden. The relative risks (with 95% confidence 

intervals) of lung cancer in relation to categories of 

surface-based average domestic radon concentration 

during three decades, delimited by cutpoints at 50, 80, 

and 140 Bq m(-3), were 1.60 (0.8 to 3.4), 1.96 (0.9 to 

4.2), and 2.20 (0.9 to 5.6), respectively, with average 

radon concentrations below 50 Bq m(-3) used as reference 

category, and with adjustment for other risk factors. 

These relative risks, and the excess relative risk (ERR) 

of 75% (-4% to 430%) per 100 Bq m(-3) obtained when 

using a continuous variable for surface-based average 

radon concentration estimates, were about twice the size 

of the corresponding relative risks obtained among these 

subjects when using air-based average radon 

concentration estimates. This suggests that surface-

based estimates may provide a more relevant exposure 

proxy than air-based estimates for relating past radon 

exposure to lung cancer risk. doi:10.1038/sj.jea.7500236

> Are glass-based radon detectors used for assessing home radon

> concentrations for mitigation purposes? 

> 

> Glass-based radon detectors integrate the radon progeny over the time

> period since the glass was made, and perhaps even before then depending on

> type of sand used to make the glass. Glass-based radon detectors might be

> appropriate to for epidemiology purposes providing you know the history of

> the glass (i.e., was it bought new or used), the composition of the glass

> (how much U is in the sand used to make it), and smoking history in the

> residence and past residences. It would not be an effective means for

> measuring radon concentrations, which becomes important for mitigation

> purposes and relating the epidemiological assessment to other studies. For

> this reason, epidemiologist must include track-etch measurements, even when

> they use glass-based detectors for their correlation analyses. 

> 

> Note that the Mo study (Non-smoking women) was negative using track-etch

> radon detectors. A second published version had a slightly positive

> correlation when smokers were added and glass-based radon detectors were

> used. When using track-etch radon detectors (i.e., the best method for

> measuring long-term radon concentrations) both studies were negative.

> 

> Tom

> -- 

> Thomas Mohaupt, M.S., CHP

> University Radiation Safety Officer

> 

> 104 Health Sciences Bldg

> Wright State University

> Dayton, Ohio 45435

> tom.mohaupt@wright.edu

> (937) 775-2169

> (937) 775-3761 (fax)

> 

> "An investment in knowledge gains the best interest." Ben Franklin

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