While you read this, over 100 billion neutrinos went through your thumb.
we'd have to be doing the studies, first. second, we'd have to know what we're looking for. if the effects were subtle, generational, or multiple and confounding, it would be hard to see even if we were looking. also, im sure the sample size is small. not a lot of people/animals spend years 10 feet from high-volts lines.
also, people are generally pretty change-averse. if there were proof that our current way of life was harmful, not a lot of people would be interested in discovering, spreading, or changing due to this news, least of all the companies with a profit motive. saving the turtles is fine if all you have to do is use a metal straw instead of plastic, but ask people to inconvenience themselves (less TV, less air-conditioning, less hot water, etc) and you've got a different response.
what follows is speculation, so you can grab your pitchforks if you want but it will be a hollow victory.
I've always been suspicious of the claim that EM fields have zero effect on human beings, especially near high-volts lines. It doesnt seem possible. Our bodies function based on electrical signals and many cellular mechanisms are mediated with ions.
do we have a list of all electrically-sensitive bodily processes? could we guess what would happen if their simultaneous activation changed by 5%? what about 45% or more? So much of the human body is not exhaustively understood in the general case, and certainly not in the individual case.
idk, i dont wanna go all tinfoil hat here. it just seems like circumstances are aligned for there to be large holes in our public understanding (accidentally or otherwise).
note: for whatever its worth, ive spent some time around the 8MW generators on Nimitz-class aircraft carriers[0].
[0]: https://fas.org/man/dod-101/sys/ship/cvn-68.htm