On a separate note,
This is not to disagree with much of what you wrote - just questioning the specifics of the posited polio-pesticide link, and your seeming view that viruses are NEVER the contagion that transmit disease from individual to individual -
even if what we commonly think of as a bad thing: "infectious disease", may actually in many cases be another misunderstanding of something that serves a positive utility for the species, while possibly at a risk to individuals in some instances. In fact I'm starting to think that's quite possible!
Now it would help if "infectious disease" were broken down into the spectrum of possible definitions. This topic you bring is relate to your topic, chickenpox parties, mothers' observations of beneficial infection symptoms.
An intimate friend of mine described baby sitting a few kids who had chickenpox. Her children had no vaccination, and no chickenpox.
After the infected children left and her children put to bed, she noticed during the night, a very brief "flash" of a fever, and then nothing, in her healthy children.
That "infection" could have been a hormonal learned behavioral response transmitted by saliva mist from vocal cords, inhaled, or skin contact, etc. It didn't have to be an invasion by a predatory virus particle. It could all still be related to learned hormonal responses resulting from environmental toxic exposure. Without proof of virus causation, the environmental explanation is preferred, being simpler and with abundant empirical environmental evidence.