Fundamentally the long term effects on people of
- Domestic and Industrial chemicals
- Medication
- Domestic Toiletry/cosmetic chemicals
- Environmental pollutants
- Modern industrial food production
are not really known. The statistical sample is not over a long enough time period to really show anything up.
... corresponding rises in Asthma.cancer etc are hardly a surprise.
Though, as any good statistician will tell you "correlation does not imply causation"