Chernobyl thyroid doses ?

[Franta, Jaroslav]

This message from Dr. Jaworowski was posted on another listserv.

I find it surprising to see such low radiation doses to the thyroid in the

highly contaminated regions of the former USSR - particularly the Gomel

region (Belarus).

I seem to recall reading somewhere that thyroid doses as high as several

thousand rem were received by individuals contaminated with I-131 in the

early post-accident fallout.

Would anyone in Radsafe be able to clarify this, please ?

Thanks.



Jaro 



 

----- Original Message ----- 

From: Zbigniew Jaworowski 

To: Jerry Cuttler 

Sent: Thursday, July 03, 2003 2:18 PM

Subject: Re: A question regarding the mortality of Chernobyl thyroid cancer

cases 





Dear Jerry,

 

I believe that the radiation doses to the thyroid in the highly contaminated

regions of the former USSR were not high enough to produce thyroid cancers.

In the famous Gomel region (Belarus) the average dose was 177 mGy, in

Bryansk region (Russia) 37 mGy, and in eight most contaminated districts in

Ukraine 380 mGy (UNSCEAR 2000 vol. 2, page 537, Table 40). These doses are

smaller than doses received by about 30 000 Swedish patients  diagnosed with

131-I, among which no increase but a deficit of thyroid cancers was found.

 

>From the text of "Chapter V" it appears that there was more than 4000

thyroid cancers in the Belarus alone, and they were regarded as a Chernobyl

effect. According to UNSCEAR data, and from what I heard during

presentations of Dr. Ivanov (Russia) and Dr. Keningsberg (Belarus), during

the 2003 UNSCEAR meeting, the total number of thyroid cancers counted as

caused by Chernobyl radiation is about 2000, and the total deaths due to

these cancers was about 3 children. 

 

The first increase in thyroid cancers was recorded in Russia already in

1987, which disagrees with all that we know about radiogenic cancers. The

maximum incidence of thyroid cancers (Bryansk region) was in 1994 of 0.027%.

This should be compared with the incidence of "occult" thyroid cancers,

which are present in populations of all countries, and range between 5.6% in

Colombia, 9% in Poland, 10% in Minsk (Belarus), 13% in the contiguous USA,

28% in Hawaii and 35% in Finland. This shows how great is the potential for

the screening effect. 

 

These occult cancers are histollogically the same as "Chernobyl" cancers -

invasive and aggressive. However, they do not pose clinical problems during

the lifetime of a person in which, earlier, they usually were discovered at

the post mortem, and now more often by USG examination. Thyroid cancers with

clinical symptoms have a good prospect of cure; up to 95% are cured.

 

Best wishes,

 

Zbigniew

 

----- Original Message ----- 

From: Jerry Cuttler 

To: Zbigniew Jaworowski 

Sent: Tuesday, July 01, 2003 4:06 P

Subject: A question regarding the mortality of Chernobyl thyroid cancer

cases 





Dear Dr. Jaworowski,

 

I hope you are having a pleasant summer.

I have a short question, which I hope you can answer for me.

I just read Chapter V (attached) of the 2002 update of the NEA report,

Chernobyl: Ten Years On.

The section on thyroid cancer includes the sentences:

 

"The histology of the cancers has shown that nearly all were papillary

carcinomata and that they were particularly aggressive, often with prominent

local invasion and distant metastases, usually to the lungs.  This has made

the treatment of these children less successful than expected, whether

undertaken in Minsk or in specialised centres in Europe."

 

Based on these two sentences, I would have expected many fatalities.  But

later on in the text, the following sentence appears:

 

"At the time of this writing, three of the 1036 children cited in Table 13

below have died of their disease."

 

As of 2002, how many of these children have actually died of thyroid cancer?

 

Thanks for your help in clarifying this matter.

 

Best wishes,

 

Jerry

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

Dr. Jerry M. Cuttler

jerrycuttler@rogers.com