gonzalez

Recommendations to the Governments of Belarus, the Russian Federation and Ukrania on environmental monitoring, remediation and research. Summary by: 

Recommendations to the Governments of Belarus, the Russian Federation and Ukrania on environmental monitoring, remediation and research. Summary by The Chernobyl Forum Vienna International Center; Vienna, Austria; September 6th, 2005 Abel J. González Autoridad Regulatoria Nuclear; Av. Del Libertador 8250; Buenos Aires; Argentina +54 1163231306;  agonzale@sede.arn.gov.ar

Slide2: 

Contamination?

Significant radionuclides: 

Significant radionuclides CAESIUM  (WHOLE BODY EXPOSURE)  IODINE  (THYROID GLAND)

Environmental monitoring and research : 

Environmental monitoring and research Environmental transfer and bioaccumulation of 137Cs and 90Sr are now well understood Little need for major new research programmes Requirement for continued but more limited targeted monitoring of the environments

Environmental monitoring and research : 

Environmental monitoring and research Long term monitoring of 137Cs and 90Sr) is required to: (Practical) To assess levels of human exposure and contamination of foods to determine the need for remedial actions; To inform the general public about the radioactive contamination in food products and its seasonal and annual variability in natural food products as well as give dietary advice.          

Environmental monitoring and research : 

Environmental monitoring and research Long term monitoring of 137Cs and 90Sr) is required to: (Scientific) To determine parameters of long-term transfer of radionuclides in various ecosystems and different natural conditions to improve predictive models; To determine mechanisms of radionuclide behaviour in less studied ecosystems (e.g., role of fungi in the forest).

Remediation and countermeasures: 

Remediation and countermeasures

Remediation and countermeasures : 

Remediation and countermeasures Different effective long-term remediation measures are available, but their use should be justified and optimized. The general public should be informed and involved in the decision-making process.

Slide10: 

INTERVENTION MAY POSSIBLY BE JUSTIFIABLE INTERVENTION IS NOT LIKELY TO BE JUSTIFIABLE INTERVENTION ALMOST ALWAYS JUSTIFIABLE mSv/year 100 10 1 EXTANT ANNUAL DOSE TYPICALLY HIGH AVERAGE NATURAL BACKGROUND VERY HIGH 100 10 1

Remediation and countermeasures : 

Remediation and countermeasures Remediation measures on radiocaesium in soil may be justified in agricultural areas with sandy and peaty soils where there might be a high transfer from soil to plants.

Remediation and countermeasures : 

Remediation and countermeasures Efficient regular agricultural countermeasures are: Radical improvement of pastures and grasslands as well as draining of wet peaty areas may be an effective remediation measure Enhanced application of mineral fertilisers in plant breeding, application of Prussian Blue to cattle and pre-slaughter clean feeding accompanied with in-vivo monitoring.

Remediation and countermeasures : 

Remediation and countermeasures There are still agricultural areas in the three countries which are out of use. However this land can be safely used after appropriate remediation.

Remediation and countermeasures : 

Remediation and countermeasures Restricting harvesting of wild food products such as game, berries, mushrooms and fish from ‘closed lakes’ by the public may still be needed.

Remediation and countermeasures : 

Remediation and countermeasures It is unlikely that any future countermeasures to protect surface waters will be justifiable. Restrictions on consumption of fish may remain in a few closed lakes.

Slide16: 

137Cs activity concentrations in predatory Pike fish from Kiev reservoirs Codex level

Slide17: 

137Cs activity concentrations in non-predatory Bream fish from Kiev reservoirs Codex level

Remediation and countermeasures : 

Remediation and countermeasures Particular attention must be given to the production of milk where 137Cs concentration may exceed action levels.

Slide19: 

Codex level 137Cs activity concentration in milk

What is the main problem?: 

What is the main problem?

…radionuclides released during the accident might be incorporated into materials, goods, merchandises, products…: 

…radionuclides released during the accident might be incorporated into materials, goods, merchandises, products…

…and, in general, into any “commodity” of public use.: 

…and, in general, into any “commodity” of public use.

Slide23: 

September 2000: IAEA General Conference, following a request from Belarus, decided the development of radiological criteria for radionuclides in commodities.

Slide27: 

Codes Alimentarious levels (incorporated into the BSS as generic action levels for foodstuffs)

Slide28: 

Guideline levels for radionuclides in foods

Drinking water: 

Drinking water The WHO levels

Environmental aspects of the shelter dismantlement and radioactive waste management : 

Environmental aspects of the shelter dismantlement and radioactive waste management A comprehensive safety and environmental impact assessment should be performed. Development of an integrated radioactive waste management programme for the Shelter. Strategy for rehabilitation of the Exclusion Zone Overall plan for the long-term development of the Exclusion Zone

Epilogue: 

Epilogue Preservation of the vast tacit knowledge that is available on the Chernobyl experience. What to do?

Slide32: 

….and patience!!

Detectability limits in radioepidemiology: 

Detectability limits in radioepidemiology Because radiation is a weak carcinogen, it is practically impossible to detect effects at low doses.

Slide34: 

Control group “N” people “C” cancers “n” probability of ‘natural’ cancer Exposed group “N” people “E” cancers “n” probability of ‘natural’cancer ‘pD’ probability of ‘radiation’ cancer

Epidemiological significance: 

Epidemiological significance The expected number of cancers in the control group will be: C = n N The expected number of cancers in the exposed group will be: E = n N + pd D N The expected number of excess cancers will be E – C

Slide36: 

E-C Difficult to detect!

Epidemiological significance: 

Epidemiological significance The standard deviation is  =  2 n N + pd D N If the excess cancers are to be detected with a statistical confidence of 95% E – C > 2 

Epidemiological significance: 

Epidemiological significance Operating algebraically and as n >> pd D, N > constant / D2 which is the equation giving the number of people, N, needed for detecting excess cancers at dose D. (Constant = 8 n / pd2)

Slide39: 

Dose (mSv) People Region of detectability Region of undetectability 1 mSv 10 9 p. DETECTABILITY OF SOLID CANCERS

Slide40: 

Dose (mSv) People Region of detectability Region of undetectability Chernobyl doses ~50 mSv Population ~270 000 DETECTABILITY OF SOLID CANCERS

Epidemiological significance thyroid cancer in children: 

Epidemiological significance thyroid cancer in children

Thyroid cancer in children in Belarus: 

Thyroid cancer in children in Belarus

Slide43: 

Dose (mSv) People Region of detectability Region of undetectability ~10 mSv DETECTABILITY OF HEREDITABLE EFFECTS ~1010 people!

Slide44: 

Dose (mSv) People Region of detectability 0.001 Sv 100.000.000 p. 100.000 man Sv x 5%/Sv = 5000 deaths!

Slide45: 

Dose (mSv) People Region of detectability Do the effects in this region actually occur? Epistemological Limitation No grounds of knowledge!!

Slide46: 

….and patience!!

Responding to this demand, three years ago, the IAEA General Conference requested that commodities requiring regulatory control shall be identified.: 

Responding to this demand, three years ago, the IAEA General Conference requested that commodities requiring regulatory control shall be identified.

Slide48: 

If it is satisfied that the doses of radiation incurred will be trivial, the competent authority should waive the requirements of …… : …operations which do not involve the use of radioactive substances at concentrations exceeding 0.002 Ci/g (74 Bq/g) or solid natural radioactive substances at concen-trations exceeding 0.01 Ci/g (370 Bq/g).

I.e., it can be construed that the first BSS applied to controllable operations involving radioactive substances at concentrations exceeding: 

I.e., it can be construed that the first BSS applied to controllable operations involving radioactive substances at concentrations exceeding some 10’s of Bq/g!

Slide50: 

1000 miles

Slide51: 

2001 – 2004: Extensive discussion! foodstuffs and water WHO and FAO

Slide52: 

2001 – 2004: Extensive discussion! foodstuffs and water other materials WHO and FAO IAEA: DS161

Epidemiological significance Solid Cancers: 

Epidemiological significance Solid Cancers N > ~109 / D2

Not surprisingly, people (and their representatives) have been asking a simple basic question to the radiation protection community:What is the radioactivity level below which the commodities are safe to be used without any control?: 

Not surprisingly, people (and their representatives) have been asking a simple basic question to the radiation protection community: What is the radioactivity level below which the commodities are safe to be used without any control?

Commodities carry becquerels (or curies) NOTsieverts (or rems): 

Commodities carry becquerels (or curies) NOT sieverts (or rems) Therefore, levels should be derived in terms of Bq/kg rather than in terms of hypothetical individual doses.

Slide56: 

Our problem is to provide a rational, logical and sustainable answer to these simple questions!

Slide57: 

Dose (mSv) People Region of detectability Region of undetectability Liquidators’ av.doses ~10 mSv Chernobyl liquidators ~160 000 DETECTABILITY OF LEUKÆMIAS

Relatively low doses:Exposure of residents affected by Chernobyl: 

Relatively low doses: Exposure of residents affected by Chernobyl Average doses (1986-1995) External Internal Total Russian Federation 4 2.5 6.5 mSv Belarus 5 3 8 mSv Ukraine 5 6 11 mSv Average (10 years) 5 3 8 mSv (lifetime) 9 4 13 mSv