Glass-Based Radon Measurements

[epirad@mchsi.com]

Two recent papers that may be of interest.  



Regards, Bill Field

bill-field@uiowa.edu



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.

--------------------------------------------





Health Phys 2002 Aug;83(2):261-71  





210Po implanted in glass surfaces by long term exposure 

to indoor radon.



Steck DJ, Alavanja MC, Field RW, Parkhurst MA, Bates DJ, 

Mahaffey JA.



Physics Department, St. John's University, Collegeville, 

MN 56321, USA. dsteck@csbsju.edu



Recent epidemiologic investigations of the relationship 

between residential radon gas exposure and lung cancer 

relied on contemporary radon gas measurements to 

estimate past radon gas exposures. Significant 

uncertainties in these exposure estimates can arise from 

year-to-year variation of indoor radon concentrations 

and subject mobility. Surface implanted 210Po has shown 

potential for improving retrospective radon gas exposure 

estimates. However, in previous studies, the ability of 

implanted 210Po activity to reconstruct cumulative radon 

gas exposure was not tested because glass was not 

available from homes with known radon-gas concentration 

histories. In this study, we tested the validity of the 

retrospective radon gas reconstruction using implanted 

210Po surface activity by measuring glass surfaces from 

homes whose annual-average radon gas concentrations had 

been measured almost every year during two decades. 

Regression analysis showed a higher correlation between 

measured surface activity and cumulative radon gas 

exposure in these homes (R2>0.8) than was observed in 

homes where only contemporary radon gas measurements 

were available. The regression slope (0.57 ky m(-1)) was 

consistent with our earlier retrospective results. 

Surface activity measurements were as reliable for 

retrospective radon gas exposure reconstruction as 

yearlong gas measurements. Both methods produced 

estimates that were within 25% of the long-term average 

radon gas concentrations in a home. Surface measurements 

can be used for home screening tests because they can 

provide rapid, reliable estimates of past radon gas 

concentrations. Implanted 210Po measurements are also 

useful in retrospective epidemiologic studies that 

include participants who may have been exposed to highly 

variable radon concentrations in previously occupied or 

structurally modified homes.





************************************************************************

You are currently subscribed to the Radsafe mailing list. To unsubscribe,

send an e-mail to Majordomo@list.vanderbilt.edu  Put the text "unsubscribe

radsafe" (no quote marks) in the body of the e-mail, with no subject line.

You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/