I heard someone (in the correct area of expertise) describing how he had visited a developing country and tested the water in a river downstream of an antibiotic manufacturing plant, and found the concentration of a particular antibiotic to be approximately the same as what you would typically want to achieve in the blood of a patient.

If that isn't going to drive resistance to that particular antibiotic, I don't know what will.

People say things like this, but how many antibiotic compounds are in the soil naturally? Living creatures exist in an environment with countless bacteria and evolve to survive, and some of the compounds they produce are turned into human drugs. So I feel like there's something missing in the ordinary narrative about antibiotic resistance. Where did penicillin come from again?