Regulation of foodstuffs contaminated with radioactive substances after the Chornobyl

NPP Accident

Oleg NasvitNational Institute for Strategic Studies,

Ukraine

Regulation of foodstuffs contaminated with radioactive substances after the Chornobyl NPP accident, Bq/kg(l)

Product nameIntroduced

06.05.86(131I)

30.05.86(βΣ)

15.12.87(137+134Cs)

06.10.88(137+134Cs)

22.01.91(137+134Cs)

UkrainePL-97(137Cs)

Japan,01.04.12

Water 3700 370 20 20 20 2 10Special infants’ food 370 370 185 40 50

Bread 370 370 370 370 20 100Milk 3700 370 370 370 370 100 100

Cheese 74000 7400 370 370 370 100Butter 74000 7400 1110 1110 370 100Meat 3700 1850 1850 740 200 100Fish 37000 3700 1850 740 150 100

Vegetables 37000 3700 740 740 600 40 100Potato 3700 740 740 600 60 100

Fresh wild berries and mushrooms

18500 1850 1480 500 100

Dried wild berries and mushrooms

11100 7400 2500 100

Dose limits for population after Chornobyl: 1st year – 100 mSv; 2nd and 3rd – 30 mSv; 4th – 25 mSv; since 1991 – 5 mSv (internal, TPL-91)

Approach PL-97

• Critical age group• Permissible daily intake of RN• Reference ration• Reference dose structure• Share of RN for each food product according to

reference dose structure• Permissible concentrations (PL)• 100% contaminated food to PL, reference ration,

1 mSv/year for each RN (137Cs, 90Sr)

Critical age group(s)

Age Age range, years

Dose conversion factors, Sv/Bq

137Cs 90Sr

3 months 0-1 2.10E-08 2.30E-07

1 year 1-2 1.20E-08 7.30E-08

5 years 2-7 9.60E-09 4.70E-08

10 years 7-12 1.00E-08 6.00E-08

15 years 12-17 1.30E-08 8.00E-08

Adults >17 1.30E-08 2.80E-08

Permissible daily intake: 137Cs 210 Bq; 90Sr 35 Bq

Reference ration and dose structure

Reference ration (1990)Products Daily

consumption, kgPotato 0,359

Meat 0,186

Milk 1,022

Vegetables 0,279

Fish 0,048

Fruits 0,129

Bread 0,386

Eggs, ps. 0,745

Total 2,409

Reference dose structureProducts 137Cs 90Sr

Potato 0,07 0,11

Meat 0,21 0,09

Milk 0,58 0,48

Vegetables 0,04 0,17

Fish 0,03 0,05

Fruits 0,05 0,04

Bread 0,02 0,06

Total 1,00 1,00

Special infants’ food

• Considered separately• Total annual dose (Cs+Sr) not more than 1 mSv• Daily intake 137Cs 40 Bq, 90Sr 13 Bq• Daily ration not more than 1 kg

Conservatism

Age groups Integrated conservatism factors137Cs 90Sr

1-2 7.3 4.3

2-7 7.6 5.8

7-12 5.8 3.5

12-17 3.5 2.3

Adults 2.9 5.3

Contributors1.Real ration v. reference2.Different age groups v. critical3.Actual contamination levels distribution v. 100% PL

• Дякую за увагу • Спасибо за внимание• Thank you for your attention• ありがとうございました