There is far less environmental contamination now than there was in 1970.

And modern agriculture practices result in lower amounts of less toxic substances in the food supply.

This doesn't really average. There's less lead, but more micro plastics for example. There less cadmium, but more pesticides. Etc.

microplastic contamination, for one, is much higher now than the 1970s. who knows what else we arent measuring for carefully