It's an easy guess because either human genetics either radical changed or the environment did

"Silent Spring" came out over sixty years ago

https://en.wikipedia.org/wiki/Silent_Spring

got massive coverage including a worldwide CBS News broadcast back then

Government and industry were never held to account and instead deregulated everything

We still allow leaded gas to be sprayed all around airports where everyone is exposed during travel and neighborhoods nearby

Golf Course neighborhoods are some of the highest cancer rates in the country

We've learned nothing and now the environment is so saturated with toxins that the immune system is under attack from birth