Did the study that showed an increased cancer incidence control for all the non-EMF factors that electrical workers might be exposed to. Stuff like PCBs, asbestos, solvents, ozone, etc.?
My understanding is that there isn't any known mechanism for EM fields to induce cancer, or cause any other bioeffects beyond simple heating. Cancer requires the disruption of DNA, and non-ionizing EM radiation doesn't deposit enough energy to do that.
This isn't to say that some such mechanism doesn't exist, just that it isn't yet known to science. But given the difficulty in teasing out a clear causal relationship between EMFs and cancer, any increased cancer risk that may be found in the future seems likely to be so small as to be hiding in the statistical noise floor.
