Well obviously the immediate effects of being poor and living in a third world country are going to dominate any long term effects of chemical buildup, all the more so in polluted areas where the individual may be exposed to much higher levels of toxic chemicals in general.

The rest of your comment seems irrelevant. I'm not disputing in any way that plants have toxins or that we had to develop various practices to make us safer. I don't dispute that many man-made chemicals are safe and useful. I don't even dispute that pesticides could conceivably improve safety from a hypothetical insect-born contagion.

However genetically modified mono-crops sprayed with heavy loads of pesticides simply to increase yields does not strike me as something that goes towards food safety at all. It goes towards short-term profit, and you can bet the cost of any long term health effects is simply ignored until 30-40 years down the line when the soil is depleted and the effects of various pesticides have time to show up in the human population. At that point the industry will throw its hands up in the air and say "how could we have known?" while pushing the new and improved fertilizers and pesticides with a new batch of as-of-yet-unknown problems.

That's why I think it's a good idea to eat more traditionally raised food. It's not because I'm some hippie idealogue or because I don't believe in science or progress, it just strikes me as a safer bet given the severe holes in nutrition science, and in many ways, the intractability of solving the health "equation".