Epidemiological principles for EMF and EMR studies - Lincoln ...

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A survey of Canadian homes was carried out to compare the typical and 48 hr
average exposure of children across five provinces, Deadman et al. (1999). There
were highly significant variations between the average home and school magnetic
fields. The mean for homes was 1.41 mG, with the highest province being Quebec
at 1.90 mG and the lowest being Alberta at 0.62 mG. For schools the average was
1.16 mG, with Manitoba being the highest at 1.56 mG and Alberta being the lowest
at 0.70 mG. These show ranges of over a factor of 2 in the children's home and
school mean magnetic field exposures.
For the surveyed Canadian children the median exposure is 0.83mG and the
95%ile is over 4 times higher at 3.54mG. The ratio between the 25%ile and the
95%ile is 7.53mG, Figure 12. An European occupational magnetic field exposure
survey is given in Figure 13.
Figure 13: The Frequency distribution of occupational exposure to magnetic fields
in Europe.
The median in exposure is 0.06µT (0.6mG) and the average is about 0.12µT
(1.2mG) with a small proportion of high exposures above 0.6µT (6mG). The
distribution is very close to the childhood exposure survey in Canada.
These surveys from the U.S., Norway and Canada show how varied are the mean
50/60 Hz magnetic field exposures for individual children, for homes, schools and
regions. The exposure intensities vary over ranges for which extremely important
and highly significant health effects are shown to occur. The ability and the need to
minimize exposures is clearly evident. Keeping schools and homes well away from
high voltage powerlines, keeping household wiring away from children’s and adults’
bed, domestic energy efficiency reducing electrical energy requirements, are a vital
elements of the risk reduction strategy that is necessary to reduce the incidence
and risk of serious illness and death for children and adults.