Chemist here. Pretty sure it is the pesticides. Farmers aren't living as long as their parent farmers. Pesticides are linked to many diseases in farmers . " ...it was observed that 12 out of 30 pesticides used worldwide were associated with an increased risk of some cancers, in particular those of the prostate, lung, colon, and/or pancreas. In addition to the increased risk of cancer, medical studies have documented fertility and pregnancy impacts in agricultural workers among other significant health conditions."