The unknown dangers of metabolites from pesticides, herbicides, and such

It is unfortunately common practice for people, businesses, and governments to spread pesticides, herbicides, fungicides, miticides, mosquitocides, pollutants, and who knows what else all over the place, often even. They seem to think that once they are no longer the pesticide or herbicide, that they are no longer a concern, and many times seem to suppose that they disappear altogether. What they seem to neglect is that matter doesn't just disappear. It either remains what it is or turns into something else, and you may or may not like that something else.