The risk doesn’t seem to be significant but the science isn’t “done”. It was often child hood leukaemia that was the main concern and a recent pooled study found there was a small increase in proximity to power lines but apparently not due to magnetic fields from the lines.
https://www.nature.com/articles/s41416-018-0097-7
Would I buy a house under power lines? I wouldn’t rule it out for that reason but it’s not as simple as saying there’s no risk.
This is a good point. Possible v small risk (but no plausible biological mechanism identified, correlation vs causation incredibly hard to prove). What’s interesting is that if there is causation here, it would account for 2-5 cases nationally per year. Most (90%) childhood leukaemia is curable, too. Vs hundreds of childhood pedestrian deaths on the roads each year:
https://www.statista.com/statistics/324018/pedestrians-killed-or-injured-in-road-accidents-in-great-britain/
Based on that, I’d be far more concerned about living near a busy road – both for reasons of accidents but also air pollution. Or a river that might flood etc. But I also wouldn’t want to live near a Pylon, they’re an eyesore and are noisy. Obviously a lot of people don’t have that luxury of choice.