I wonder if PCBs play a part in it. I was reading that thanks to Monsanto pushing PCBs like they are candy has resulted in basically the whole world being exposed to them.

They're hormone disruptors that cause a lot of side effects like decrease of intelligence, weight gain, early/late puberty and it is impossible to escape them completely since even though they're no longer manufactured (at least not in the USA legally) they take a long time to break down in the environment.

https://www.clearwater.org/news/pcbhealth.html