Re: LNT, Collective Dose

[Ted de Castro <tdc@xrayted.com>]

Its in the Math harry - its all in the math!  Its called statistical
sampling.  THAT is how you determine how much is enough.  It is an
acceptable technique used to gather ENOUGH data to be able to reliably
test a hypothesis.

Of course actual sums of actual tests would be more accurate - but
enormously expensive and not necessary to test the hypothesis.

Your simple offer of collecting samples from HPs for zip codes is no
where near as statistically representative as Cohens averaged data -
there simply aren't that many HPs!!!

To collect the individual data would take a national level government
funded mandatory program.  And very few of us would want to pay the
taxes that would cost nor tolerate that level of intrusion into out
private lives.  I wouldn't!  Maybe in a more totalitarian state this
could be done.

Harry Hinks wrote:
> 
> Ted,
> 
> No offense taken.  I will keep trying.  I thank you for your patience.
> In fact, I agree with what you say below.  The point I was trying to make is
> that you don't need to make these assumptions for individual level studies

But the point is that you don't NEED _NOT_ to make these assumptions. 
You simply can afford to do the study without making them.

> in the low dose area such as the studies by Wichmann, Darby, Field, Alavanja
> and others.  You have to make assumptions of collective dose for summary
> level studies and studies at high dose such as miners if you want to make
> the risk adjusted for lower level radon exposures.
> 
> Harry
> 
> At the plate and being hit on the head.
> harryhinks@hotmail.com
> 
> >In a linear risk situation its the same thing!  That is PRECISELY the
> >point that many are trying to make here - the summing of person
> >microREMs into populational REMs and then declaring cancer deaths!
> >
> > >
> > > In studies where you collect data at each house, you do not have to make
> > > either LNT or the collective dose assumptions.  Assume you go out to the
> > > nearest town and randomly choose 3 homes to test their radon in their
> > > basement.  Again assume you get readings at the 3 houses of 24
> > > pCuries/liter, 2 pCuries/liter and 1 pCuries/liter.  With summary data
> >using
> > > the collective dose assumptions, you would assume the basement
> >concentration
> > > for each individual in that town is 9 pCuries/liter, correct?  But in
> > > reality, you know the basements were 24, 2 and 1.   In studies using
> >data
> > > from individual houses, you have the readings.  In summary data studies,
> >you
> > > do a poor job of measuring the actual concentrations.
> > >
> >
> >Well I'll try once again.
> >
> >If the risk is LINEAR it is proportional to dose.
> >
> >If that risk is R then in house 1  the risk is 24R in 2 its 2R in 3 its
> >1R.
> >
> >Risk for that population is then the sum of the individual risks
> >
> >= 24R+2R+1R = 27R
> >
> >For LNT the average exposure is as you say 9 - thus the average risk is
> >9R thus the total risk for the population of 3 is 27R!!!
> >
> >With LNT the prediction is NOT WHO - BUT HOW MANY!
> >
> >This is precisely what LINEAR means.
> >
> >I think this is what Jim means to by "missing the point".  I'm not
> >saying this in a mean way or suggesting any purposeful intent.
> >
> >Its is simple math - its is the definition of a linear co-efficient.
> >
> >IF this doesn't work - then it is NOT linear!
> >
> >I'm not disagreeing with how you suggest the risk should be apportioned
> >- I infact do agree - I agree it isn't linear!
> >
> >All you arguments are predicated on a supposition that it is NOT linear.
> >
> >I don't know your math or statistics background so I cannot comment
> >further - but there is nothing magical or mysterious about it.
> >
> >THINK about it for a minute.
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