Do you know what you’re breathing? It’s good to know. People often learn by doing; but sometimes the learning process is painful or even fatal.
I once had a professor begin a lecture with: “Sewage is purer than Ivory Snow.” This statement juxtaposed the advertised purity of the soap with the fact that sewage is 99.99% water. The purity of the air, the effects quantified by surveys and studied in laboratories, and the duration of exposure; all need to be judged in terms of human health.
Factory farms take a lot of the bad things from human industrialization; and put it all in one place — the rural community. If it was anywhere else they would be shut down.