Study type: Epidemiological study (observational study)

Power-frequency magnetic fields and childhood brain tumors: a case-control study in Japan epidem.

Published in: J Epidemiol 2010; 20 (1): 54-61

Aim of study (acc. to author)

A case-control study was conducted in Japan to investigate the association between exposure to power-frequency magnetic fields and childhood brain tumors.

Endpoint/type of risk estimation

Type of risk estimation: (odds ratio (OR))



Exposure groups

Group Description
Reference group 1 bedroom magnetic field level: below 0.1 µT
Group 2 bedroom magnetic field level: 0.1-0.2 µT
Group 3 bedroom magnetic field level: 0.2-0.4 µT
Group 4 bedroom magnetic field level: above 0.4 µT


Case group

Control group

Study size

Cases Controls
Eligible 167 -
Participants 72 189
Evaluable 55 99
Statistical analysis method: (adjustment: )

Results (acc. to author)

The risk of brain tumor was significantly higher among children whose bedroom magnetic field level was greater than 0.4 µT (OR 10.9, CI 1.05-113). A not statistically significant increased risk was observed for children whose bedroom magnetic field level was in the range of 0.2 to 0.4 µT (OR 1.58, CI 0.25-9.83).
The authors concluded that a positive association was found between exposure to magnetic fields above 0.4 µT and the risk of childhood brain tumors. This association could not be explained solely by confounding factors or selection bias.

Limitations (acc. to author)

The findings are based on low numbers.

Study funded by

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