Trends in childhood leukaemia in the Nordic countries in relation to fallout from atmospheric nuclear weapons testing.
OBJECTIVE
To obtain further information about the risks of childhood leukaemia after exposure to ionising radiation at low doses and low dose rates before or after birth or to the father's testes shortly before conception.


METHODS
Observational study of trends in incidence of childhood leukaemia in relation to estimated radiation exposures due to fallout from atmospheric nuclear weapons testing during the 1950s and 1960s.


METHODS
Nordic countries.


METHODS
Children aged under 15 years.


METHODS
Incidence rates of leukaemia by age at diagnosis, sex, country, and calendar year of diagnosis or year of birth; exposure category; relation between leukaemia and exposure for children aged 0-14 and 0-4 separately.


RESULTS
During the high fallout period the average estimated dose equivalent to the fetal red bone marrow was around 140 mu Sv and the average annual testicular dose 140 mu Sv. There was little evidence of increased incidence of leukaemia among children born in these years. Doses to the red bone marrow of a child after birth were higher, and during the high exposure period children would have been subjected to an additional dose equivalent of around 1500 mu Sv, similar to doses received by children in several parts of central and eastern Europe owing to the Chernobyl accident and about 50% greater than the annual dose equivalent to the red bone marrow of a child from natural radiation. leukaemia incidence and red marrow dose was not related overall, but rates of leukaemia in the high exposure period were slightly higher than in the surrounding medium exposure period (relative risk for ages 0-14: 1.07, 95% confidence interval 1.00 to 1.14; for ages 0-4: 1.11, 1.00 to 1.24).


CONCLUSIONS
Current predicted risks of childhood leukaemia after exposure to radiation are not greatly underestimated for low dose rate exposures.
Darby
S C
SC
Imperial Cancer Research Fund Cancer Epidemiology Unit, University of Oxford, Radcliffe Infirmary, United Kingdom.
Olsen
J H
JH
Doll
R
R
Thakrar
B
B
Brown
P D
PD
Storm
H H
HH
Barlow
L
L
Langmark
F
F
Teppo
L
L
Tulinius
H
H
D000293:Adolescent; D000367:Age Factors; D001853:Bone Marrow / Q000528:radiation effects; D002648:Child; D002675:Child, Preschool; D005260:Female; D005333:Fetus / Q000528:radiation effects; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007953:Leukemia, Radiation-Induced / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D009689:Nuclear Warfare; D011847:Radioactive Fallout / Q000009:adverse effects*; D012042:Registries; D012307:Risk Factors; D012537:Scandinavian and Nordic Countries / Q000453:epidemiology; D013737:Testis / Q000528:radiation effects
D011847:Radioactive Fallout