RESEARCH INSTITUTE OF RADIOLOGY

Dr. Viktor AVERIN, Director

Outline 137Cs and 90Sr contamination of agricultural lands

Decontamination in Belarus

Measures taken to reduce 137Cs accumulation by crops

Permissible levels of 137Cs concentrations in food

Food processing and its effects

Application of cesium binders and its effects

Alteration of production line to reduce collective doses

Alternative use of contaminated grain crops

Milk processing and its effects on 137Cs / 90Sr in end products 

137Cs and 90Sr Contamination of Agricultural Lands

137Cs contaminated farmlands, thousands of hectares

Total137Cs

Contamination density, kBq/m2 (Ci/km2)

37–185 (1– 5)

185 – 555 (5 –15)

555 –1110 (15 – 40)

> 1480 (> 40)

BELARUS TOTAL 1055.8 804.0 220.5 31.0 0.2

Gomel Region 602.7 443. 7 139.1 19.8 0.2

90Sr contaminated farmlands, thousands of hectares

Total90Sr

Contamination density, kBq/m2 (Ci/km2)

5.55 –18.5 (0.15 – 0.5)

18.5 – 74(0.5 – 2)

74 –111 (2 – 3)

> 111(> 3)

BELARUS TOTAL 375.0 294.3 78.3 2.3 0.07

Gomel Region 352.6 272. 0 78.3 2.3 0.07

As the tables show, Gomel region, closest to the Chernobyl NPP, is still the most contaminated area of Belarus out of its 6 administrative units.

Decontamination500 settlements of Belarus were decontaminated during 1986-1989 period, 60% – in 2-3 stages.

removal of contaminated soil and "clean" refilling; dismantling of objects not subjected to

decontamination; asphalting of streets, roads and pavements; roof replacement; waste disposal.

7.3 million m3 of soil was cut off and replaced with 1.57 million m3 of clean soil.

Decontamination in Belarus INTERVENTION LEVELS

Object of Decontamination

Gamma Radiation, μR/h, orBeta Radiation, particle/min·cm2 Action

Territories of pre-school facilities, schools and private houses

35-40 μR/hRemoval of 25-cm soil

layer

Working office and operational places:- permanent being- temporary being

50 μR/h100 μR/h

Cleaning with detergents and water

Open areas within settlements (stores, public places)

60 μR/hRemoval of 25-cm soil

layer

Inner surfaces of houses;transportation means

20 particle/min·cm2 Cleaning with detergents and water

Roofs of buildings 40 particle/min·cm2 Cleaning with detergents and water

Decontamination/demolition activities

Decontamination in Belarus~ 25 thous. tons of solid wastes per year

~ 20 tons of liquid wastes per year

Disposal Facilities for Decontamination Waste (DFDW)

DFDW-Ifor DW

>100 kBq/kg

DFDW-IIfor DW

1-100 kBq/kg

DFDW-IIIwere urgently

constructed in 1986-1989

1 site "Khatki"

9 sites 82 sites

1991–2011: disposal of 709 thousand tons of decontamination waste with total activity of 361×1010 Bq

Effectiveness of Agrotechnical and Agrochemical Techniques in Post‐Accident Reduction of 137Cs Accumulation by Agricultural Crops

Application of potassium fertilizers

Optimization of nitrogen fertilization rates

Basic soil improvement

Surface improvement

Selection of grass mixtures

137Cs reduction factor

Selection of crop types with minimal uptake ability

Soil treatment (real tillage, deep tillage)

Lime treatment (lime dose: 1,5 hr)

Application of organic fertilizers

Application of phosphate fertilizers

Gradual Revision of 137Cs Permissible Levels in Food, Bq/kg

370 370111

111 100

1850

740600 600

500370 370

185

74 40TPLs-88 TPLs-91 RPLs-92 RPLs-96 RPLs-99

Milk and whole milk products Meat and meat products Bread and cereal products

TPLs – Temporary Permissible Levels RPLs – Republican Permissible Levels 

RPLs‐99 revised and accepted in y.1999 is a current national standard for 137Cs content in food

Permissible Levels for 137Cs Concentrations in Food (Bq/kg, Bq/l)

FOOD PRODUCT

STANDARDS

RPLs-99 CUSTOMS UNION

Drinking water 10 not defined

Condensed and concentrated milk 200 300

Quark (cottage) cheese and related products  50 100

Rennet cheese and cream cheese spread 50 50

Butter 100 200

Pork, poultry and related products  180 200

Venison and wild game not defined 300

Fish and fish products not defined 130

Dried and salted fish not defined 260

Potatoes and root vegetables 80 80

Vegetables 100 80

FruitsGarden berries

4070

not defined

Mushrooms  370 500

Dried mushrooms 2500 2500

Dynamics of 137Cs Concentrations in Milk of a Private Farming Sector 

Period Reduction Factor Half-life, T1/2

1986-1987 ~ 8-10 0.4 years

1987-1988 ~ 3.5 0.6 years

1988-1993 ~ 6.5 1.6 years

1994-1998 ~ 1.2 10 years

1999-2008 ~ 1.5 14 years

2008-20.. statistically uncertain > 20 years

Т1/2 – the period of time it takes for the amount of 137Cs in milk to decrease by half

The Effects of Milk Processing on 137Cs and 90Sr Concentrations in End Products

Tf – ratio of radionuclide concentration in end product to radionuclide concentration in milk

How Processing of Contaminated Crops Effects on 137Cs in End Products, %

Oil Cereals Flour Spirits Starch Spirits

0 60 0 5 070

APPLICATION OF CESIUM BINDERS

GIESE SALT:

NH4Fe[Fe(CN)6]

NIGROVICH SALT:

KFe[Fe(CN)6]

FERROCYNE:

95% Fe4[Fe(CN)6]3+5% KFe[Fe(CN)6]

COW MILK

BEEF

GOAT MILKCHICKEN

PORK

EGGS

FERROCYNE

Reduction of Collective Doses of Population by Changing Milk to Meat Production

(given: the soil contains 20 kBq/m2 90Sr and 1000 kBq/m2 137Cs)

FODDER500 tons

137Cs – 847 MBq90Sr – 193 MBq

137Cs – 847 MBq90Sr – 193 MBq

MILK, 400 t

137Cs – 67,6 MBq90Sr – 2,9 MBq

MEAT, 37,3 t

137Cs – 4,85 MBq90Sr – 0.04 MBq

Collective doses, mZv

137Cs – 36,990Sr – 339,9

Collective doses, mZv

137Cs – 88090Sr – 232

1112

1 MBq (megabecquerel) = 106 Bq

Collective Radiation Doses after Alternative Use of Contaminated Grain Crops

Grain crops500 t

Chicken, 161 t137Cs – 2,33 MBq

90Sr – 0,017 MBq

Beef, 37,3 t137Cs – 2,16 MBq

90Sr – 0,019 MBq

Pork, 81,8 t137Cs – 1,68 MBq

90Sr – 0,004 MBq

137Cs – 40 MBq90Sr – 22 MBq

137Cs – 40 MBq90Sr – 22 MBq

137Cs – 40 MBq90Sr – 22 MBq

Bread137Cs – 40 MBq

90Sr – 22 MBq

137Cs – 26090Sr – 440

700

137Cs – 30,390Sr – 1,3

31,6

137Cs – 2890Sr – 1,5

29,5

137Cs – 21,890Sr – 0,3

22,1

Training for Schoolchildren: - Radiology basics, and - Measurements of radionuclide concentrations in

foodstuffs, feed, ambient gamma-radiation dose rates

Public Outreach and Training

Creation of the Centers for Practical Radiological Culture (CPRC) in the local schools of the affected areas

Improvement of radiological knowledge  and practical skills of radiation protection among schoolchildren and other groups of population

Public Outreach and Training 

MINISTRY FOR EMERGENCY SITUATIONS OF THE REPUBLIC OF BELARUS

Research Institute of Radiology (RIR)

16, Fedyuninski Str., 246000 Gomel, Republic of Belarus

Tel.: +375 232 51‐68‐21 Fax: +375 232 51‐68‐22E‐mail: office@rir.by

Web: http://www.rir.by