> To conduct the research, Carter and her team asked farmers to send soil samples to their lab, and also visited some farms themselves

Obviously, a concern. But the scientific-ness of the effort would have been helped using random samples, that were collected by the scientists.

For the human pharmaceuticals - Britain's National Health Service could, in theory, give preference to drugs which do not persist in the environment.

In practice, I suspect it's a rather complex situation. Might there be a Pharm.D. here, who's willing to comment?