Not sure what age groups are included but if one wants to blame pollution it would seem to make at least as much sense to blame drug use.

The drug users of the seventies are getting up to the age when they are at risk for alzheimers etc.

In addition to illegal drug use the increased use of legal drugs like pain killers, tranquilizers and anti-depressives fit into the time frame. Add to that therapeutic drugs such as beta blockers, calcium blockers, anticoagulants, etc. Not much more than 20-30 years ago medicine was nearly always for symptomatic relief. Nowdays many over age 50 are on a lifetime regimin of "therapeutic" drugs.

No drug testing that I know of can guarantee against long term effects.