What Happened Here?

When I was growing up and into my 30s I never even heard about people with ADHD, Autism, Food Allergies or for that matter Allergies of any kind. Cancer was rare. Never heard of AIDS, in fact didn't know any Gay people until I was in College. People died of other things first I guess. No one even knew of Cholesterol HDL OR LDL. Sunscreen hadn't been invented. A good tan was GOOD. We ate the wrong things, drank bad water and breathed bad air according to today's standards. We had lead paint on our windows, burned lead in our cars, played with liquid mercury, inhaled too many fumes sometimes. BUT, we survived and I guess if I am any observer..prospered. I'm glad we aren't poisoning ourselves, that we stay clean, use purel and keep kids out of danger. I just wonder if we haven't created a petri dish humanity that is now without defense from an infectious world? There must be some reason so many people are so abused of ailments never manifested before the last 40 years.