[ RadSafe ] Ranger uranium company in Australia & cancer clusters among aborigine

[Nick Tsurikov]

Dear Bjorn,

The issue does interest me (I did do some analysis several months ago)
and I would like to offer the following (maybe a bit lengthy...)
comments on the issue:
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
The Australian Institute of Aboriginal and Torres Strait Islander
Studies (AIATSIS) prepared a document of a particular interest dealing
specifically with health hazards to Aboriginal communities (Aborigines
and Uranium: Monitoring the Health Hazards, Research Discussion Paper
Number 20, Australian Institute of Aboriginal and Torres Strait
Islander Studies, December 2006).

The document "identifies a significant overall increase in the
incidence of cancer among people in the Kakadu region which is ninety
percent greater than would be expected."

The main conclusions of the document are that –
"…a significant overall increase in the incidence of cancer among
people in the Kakadu region which is ninety percent greater than would
be expected" was identified, and
"…existing data sets are not adequate to identify a definitive cause
for the increased cancer incidence.  There could be reasons for the
high cancer rates other than proximity to uranium mining and milling".
It is concluded, "there is an urgent need for continued, comprehensive
monitoring of health wherever uranium mining occurs, and for at least
twenty years after mines cease operation."

As authors of the document themselves state, the results have to be
regarded as a preliminary finding only and a further investigation is
required.

The conclusion about the increase in cancer occurrence in the Kakadu
population in 1994-2003 was made by comparison of the number of actual
cases with the expected values.  It was not considered appropriate to
use rates of cancer incidence of predominantly non-Aboriginal
populations (such as total Australian or total Northern Territory
rates) in calculations concerning an exclusively Aboriginal
population.  The comparison appears to be correct, but it will be very
useful to have the cancer rates compared with other populations as
well, at least for comparative purposes.

It also not entirely clear from the document how the overall value was
calculated and why it is 90% higher than the expected number of cases.
 It is noted that –
--> the actual number of lung cancer cases was slightly higher but not
statistically significant,
--> the actual number of thyroid cancer cases was slightly lower than
expected but also not statistically significant,
--> there were no more than two cases of any particularly cancer
diagnosed in Aboriginal persons in the Kakadu Region in this ten-year
period and none or only one case for most cancers, including thyroid
(no cases), leukaemia (no cases) and lymphoma (one case),
--> the excess of all cancers combined is not due to an excess of any
particular cancer.

The document does not specify how the value of 27 actual cancer cases
was calculated (describing what particular types of cancer were taken
into account) and how the value of 14.4 expected cancers was
calculated.  If the table 1 of the document is expanded, the reasons
for the main conclusion of the report will be clearer.

If an increase in cancer rates for the Aboriginal population is
confirmed, there will be, indeed, a need for some monitoring.  It is
likely, however, that it will be necessary to link ->particular<-
cancers with ->particular<- possible radiation exposures.
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

Basically, more information needed before ANY conclusions can be made.

Please let me know if you find the above of any help and/or you need
any additional information.
Kind regards
Nick Tsurikov
Eneabba, Western Australia



On 11/26/07, Bjorn Cedervall <bcradsafers at hotmail.com> wrote:
>
> Among what I found this far is 27 cancer cases instead of 14 expected for
> the years
> 1994-2004. I assume that this relates to incidence - not deaths.
>
> Now, in order to interpret such data it is important to understand the
> average age / life expectancy of the population: If they become older
> (because they have jobs) that could explain some of the effect - cancer
> incidence increases sharply with age (especially after age 55-60).
>
> Comments?
>
> My personal reflections only,
>
> Bjorn Cedervall   bcradsafers at hotmail.com
>
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