Wind erosion from animal croplands is the largest source of airborne particles, which irritate respiratory passages and make them more susceptible to respiratory infections. Factory farms produce a stench that poses a major nuisance (and possible hazard) to neighbors for miles around.
According to a May 2003 article in the New York Times, "Around industrial hog farms across the country, people say their sickness rolls in with the wind. It brings headaches that do not go away and trips to the emergency room for children whose lungs suddenly close up. People young and old have become familiar with inhalers, nebulizers and oxygen tanks. They complain of diarrhea, nosebleeds, earaches and lung burns."
The article goes on to describe how air pollution from hog farms appears to have caused permanent brain damage in nearby residents.