A few years ago, a power line in our local area should increase from 45 to 90kV. I was given the task to investigate the consequences.
A quick literature search gave contradictions results, some indicated increased cancer risk while others could point to no danger. The requirement for the voltage induced in the surrounding environment had be a thousandths of what would cause electric shock by taking a step, the same is set for magnetism far lower than what is needed to tear iron objects out of the pockets of people.
A local health requirement was that the distance for a 300KV power line to a house should be 30m, for a 90kV line the requirement should be 1/3 of this, 10 meter. This would cost to much so the voltage was not increased.
When there are so divergent investigations on the risk of cancer with power lines, it usually are other reasons than those investigated.
Do you go under a high voltage line on a wet and rainy day, you hear the corona effect, small discharges of charged raindrops around the power lines. The same happens with ionized air, even if it does not sound, so that there is an invisible cloud of de-ionized air around the lines. This cloud will naturally also be influenced by wind so that it can stretch away on one side, while there is nothing on the other side.
There is no difference on ionized and de-ionized air, but air contains particles from the ground and contaminants that will also be ionized by the air. Could this have consequences for people who breathe this or skin that is in contact with the air? Ionized particles will be drawn out of the air as they approach objects associated with soil. It might be necessary to investigate more about this factor and not look at pure electrical or magnetic conditions.