Glass-based radon measurements - Lagarde paper

[hflong@postoffice.pacbell.net]

Kai, Bill Field, Klaus Becker, other researchers and interested

Radsafers,

Lagarde et al in Sweden's "Glass-based radon-exposure assessment and

lung cancer risk" in J Exposure Analysis and Environmental Epidemiology

(2002) 12, 344-354 compares old glass object surface activity with

residential air radon of 110 lung cancer subjects (33 neversmokers) with

231 controls (? neversmokers). The data is from 1998 and 2000 Nyberg and

2000 Gustovson studies.



"Activity" on glass surfaces from  Pb 210 (half-life 22.26 years), they

concluded, "may provide a more relevant exposure proxy than air-based

estimates for relating past radon exposure to lung cancer risks". For

the air-based measure, they used CR-39(polyallydiglycol carbonate) alpha

track density, measured by an automatic film reader (after chemical

etch).



Clinical trial with double-blind placbo control, (DBPC, necessary for

proof of  benefit for any other  medicine) contrasts with the many

sources of selection and erroneous conclusions in Lagarde'sstudy, which

is,

1, retrospective, 2, "controls" are not identical, 3, very small in

numbers (easily manipulated), 4, has several "weighting" adjustments,

(apparently selected after the study was begun, like the choice of

stastistical method) and therefore could be easily configured to a

preselected outcome.



Kai's graph using different statistical analysis of the same data,

illustrates the potential for erroneous conclusions by showing less risk

at 80-100 Bq(m-3) than at 50-80, when Lagarde's method shows the

opposite.



Bill ("Radon Causes Cancer") Field asserts that a DBPC trial is

"impossible" with radon.

Bil says we would find few volunteers willing to subject themselves to

that risk of cancer. So, yesterday, I asked a couple of patients if they

would like to participate in a radiation benefit study. I had briefly

disclosed Field's observation in Iowa that lung cancer patients had home

radon c 5 pCi/L vs "controls" c 4, then Cohen's graph of  county lung

cancer mortality rates lower at 2-4 pCi/L than < 1.3 pCi/L (most of the

USA). Indeed, there was a problem. They wanted to be sure they were not

the plascebo controls!



Howard Long





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