The largest single group of Americans, population wise, are the baby boomers and throw in the decade before them. This huge group of people lived in houses, schools, apartments filled with lead based paint, asbestos up the ying yang, creeks and streams filled with all sorts of nasty run off, coal burning furnaces, ate lard and butter and red meat, smoked unfiltered tobacco products, drank alcohol, smoked pot and wallowed, ate, breathed etc every other nasty you can think of and as a group we live longer and we're healthier than virtually any generation.
All of my dirty filthy hippie peers that exercised obsessively, ate seeds, hulls and stems and stalked the wild Bland and whined about all the good things in life that they wanted to stamp out are all dead.