It is not that simple though. It is rational to not eat meat that contains antibiotics or fruit and vegetables that contain pesticides. But you need the time, money, resources, knowledge and organisation to actually pull it off. I don't know there is some sort of Maslow pyramid for countries, but a lot of countries might just not be ready to face this problem just yet. For instance, China wasn't too bothered about pollution until recently, they were (and still are) busy raising the general standard of living. Similarly, the United States might not be ready to attack this problem just yet because they are busy attacking... other things.