Malformation rates in Bavariafollowing the Chernobyl accident

Alfred KörbleinMunich Environmental Institute

Monthly malformation rates in Bavaria

0

2

4

6

8

10

12

84 85 86 87 88 89 90 91 92

calendar years

ma

lform

atio

n r

ate

pe

r 1

00

0

Caesium-137 deposition

in Bavaria

BfS study: no significant effect on odds ratios

-8

-6

-4

-2

0

2

4

6

8

84 85 86 87 88 89 90 91 92

calendar years

sta

nd

ard

ise

d r

esi

du

als

Ratio of maformation ratessouthern vs. northern Bavaria (odds ratios)

0,0

0,5

1,0

1,5

2,0

2,5

84 85 86 87 88 89 90 91 92

calendar years

od

ds

ratio

s

Caesium burden of pregnant women

0

10

20

30

40

50

86 87 88

calendar years

cae

siu

m c

on

cen

tra

tion

[Bq

/kg

]

Odds ratios after shifting time windows

-8

-6

-4

-2

0

2

4

6

8

84 85 86 87 88 89 90 91 92

calendar years

sta

nd

ard

ise

d r

esi

du

als

Dependency on caesium deposition

0

2

4

6

8

10

12

14

0 5 10 15 20 25 30 35

caesium-137 deposition [kBq/m²]

ma

lform

atio

n r

ate

pe

r 1

00

0

Odds ratio: Ratio of malformation rates in Nov+Dec 1987

to rates in Nov+Dec of all other years (1984-1991)

0,0

0,5

1,0

1,5

2,0

2,5

0 5 10 15 20 25 30 35 40 45

caesium-137 deposition [kBq/m²]

od

ds

ratio

Results

• No increase of malformation rates in 1987 relative to the long-term trend for Bavaria as a whole

• In Nov+Dec 1987, seven months after the maximum caesium burden of pregnant women, malformation rates are nearly 2-times higher in southern Bavaria than in northern Bavaria

• Analysis on a district level reveals a significant dependency on caesium deposition in Nov+Dec 1987

• Decrease of malformation rates in districts with low caesium deposition, increase where caesium deposition is high.Sum effect: no increase in Bavarian average, 1987