Residential exposure to extremely low-frequency magnetic fields and risk of childhood leukaemia, CNS tumour and lymphoma in Denmark.
BACKGROUND
We previously reported that children exposed to elevated extremely low-frequency magnetic fields (ELF-MF) had a five to six times higher risk of leukaemia, central nervous system (CNS) tumour and malignant lymphoma. Here we extend the study from 1968 to 1986 through 2003.


METHODS
We included 3277 children with leukaemia, CNS tumour or malignant lymphoma during 1968-2003 recorded in the Danish Cancer Registry and 9129 controls randomly selected from the Danish childhood population. ELF-MF from 50 to 400 kV facilities were calculated at the residences.


RESULTS
For recently diagnosed cases (1987-2003), the relative risk (RR) was 0.88 (95% confidence interval (CI): 0.32-2.42), while for the total period (1968-2003) it was 1.63 (95% CI: 0.77-3.46) for leukaemia, CNS tumour and malignant lymphoma combined for exposures ⩾0.4 μT compared with <0.1 μT. These results were based on five cases (recent period) and 11 cases (total period) in the highest exposure group.


CONCLUSIONS
We did not confirm the previous finding of a five- to six-fold higher risk for leukaemia, CNS tumour and malignant lymphoma when including data from the more recent time period. For the total time period, the results for childhood leukaemia were in line with large pooled analyses showing RRs between 1.5 and 2.
Danish Cancer Society Research Center, Strandboulevarden 49, 2100 Copenhagen, Denmark.
Camilla
C
Pedersen
Danish Cancer Society Research Center, Strandboulevarden 49, 2100 Copenhagen, Denmark.|Oncology Clinic, Finsen Centre, Rigshospitalet 5073, University of Copenhagen, Blegdamsvej, 2100 Copenhagen, Denmark.
Christoffer
C
Johansen
International Agency for Research on Cancer (IARC), Section of Environment and Radiation, 150 Cours Albert Thomas, 69372 Lyon, France.
Joachim
J
Schüz
Danish Cancer Society Research Center, Strandboulevarden 49, 2100 Copenhagen, Denmark.
Jørgen H
JH
Olsen
Danish Cancer Society Research Center, Strandboulevarden 49, 2100 Copenhagen, Denmark.|Department of Environmental Science, Aarhus University, Frederiksborgvej 399, Postbox 358, 4000 Roskilde, Denmark.
Ole
O
Raaschou-Nielsen
D000293:Adolescent; D016022:Case-Control Studies; D016543:Central Nervous System Neoplasms / Q000453:epidemiology / Q000209:etiology*; D002648:Child; D003718:Denmark / Q000453:epidemiology; D004781:Environmental Exposure / Q000009:adverse effects*; D006801:Humans; D007938:Leukemia / Q000453:epidemiology / Q000209:etiology*; D008223:Lymphoma / Q000453:epidemiology / Q000209:etiology*; D060526:Magnetic Fields / Q000009:adverse effects*; D012306:Risk; D012307:Risk Factors