Actually, this is a very interesting detail in the world as it is today. I used to work at the Burmese border in Thailand with karen migrants. Long story short,

Actually, this is a very interesting detail in the world as it is today. I used to work at the Burmese border in Thailand with karen migrants. Long story short, I was computerizing a cluster of clinics aimed at migrants (who happen to live in camps, mostly). While talking with a Dutch medic/light surgeon/peditrician, he revealed that the migrants didn't have any problem with providing milk (quantity/quality) to their babies while this was a growing problem in Europe and elsewhere. He said modern stress is probably responsible for a large part of the problem and the figures show a large increase since women's status changed in Europe (post-WW2). He didn't mention pollution and I don't remember really talking about milk quality so pollution might be another factor too.