Re[2]: HEAST risk estimates

[Alex.Zapantis@ea.gov.au (Alex Zapantis)]

Further to my previous message;

It makes more sense to consider this risk estimate in terms of collective dose.
Eg if 100 people together injested a total of 1GBq, you would expect 3.84
cancers to result in that population, above the "natural rate". Of course
mathematically, this is the same as 3.84 cancers in one person who ingests 1GBq,
but in reality, this would not occur.

A risk of 3.84 (cancer morbidity + mortality) equates to an effective dose of
64Sv (whole population risk factors used).The poor bloke wouldn't be around long
enough to develop cancer if this dose was delivered over a resonably short time
due to deterministic efffects!!



_______________________________________________________________________________
Subject: Re: HEAST risk estimates
From:    Alex Zapantis
Date:    15/5/98  8:03 AM

Yes, the risk is 3.84 cancers per person, viz

risk = 1.42E-10 per 1E-12Ci
     =  1.42E-10 per (1E-12 x 3.7E10) Bq
     =  3.84E-9 per Bq
     = 3.84 per GBq

Regards

Alex
_______________________________________________________________________________
Subject: HEAST risk estimates
From:    Anthony Barber <a.barber@qut.edu.au> at Internet
Date:    14/5/98  1:49 AM

Can anyone explain what the qualifier (denominator) is for the risk measure
used in the HEAST radionuclide carcinogenicity table?

Example - risk of contracting cancer from ingestion of Ac89 is given as
1.42E-10 risk per pCi or 3.84 risks for 1GBq ingested.
What is 3.84 risks? Is it 3.84%? or is it 3.84 cancers per million people
exposed or maybe it is 3.84 cancers per person exposed? (ha, ha)

I have read all the documents at the HEAST web page with no joy. Although
it is highly likely that I am simply displaying my ignorance or inablity to
comprehend documents.

All explanations gratefully accepted.

Regards


Anthony Barber
RSO - Queensland University of Technology
ph  61 7 3864 3566
fax 61 7 3864 3993
a.barber@qut.edu.au
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Why not?
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Alex Zapantis             
Health Physicist
Supervising Scientist Group

Email : alex.zapantis@ea.gov.au
Fax : (int+) 61 2  6217 2060
Phone: (int+) 61 2 6217 2037

PO Box E305
Kingston ACT 2604
AUSTRALIA

The Supervising Scientist Group is Part of Environment Australia

Alex Zapantis             
Health Physicist
Supervising Scientist Group

Email : alex.zapantis@ea.gov.au
Fax : (int+) 61 2  6217 2060
Phone: (int+) 61 2 6217 2037

PO Box E305
Kingston ACT 2604
AUSTRALIA

The Supervising Scientist Group is Part of Environment Australia