I wonder if there is a higher rate of illnesses due to lung, allergy, cancer, etc. in your area. Anything which be in direct cause to chemicals.
I can't begin to tell you the number of farmers around me who have died in the last few years....and most was due to cancer. They all work outside on multi acre farms.
Reality - in Arizona there is a lung disease called "Valley Fever." It's very dangerous if you get it and can make you deathly sick. It lives in the ground, in the dust, and is ok if you don't stir it up. When the building boom happened about 8 years ago, they were digging up the ground a lot. The dust in the air inhaled by those who are vulnerable can settle in the lung and cause this disease. Residents told us wild animals, and domestic pets die frequently from Valley Fever because they dig in the ground. When this boom was going on, it also unleashed masses or scorpions which people began to get in their garages and homes. My family moved from there to here and one of them asked a doctor is they ever treat what they call Valley Fever here in the mid-south. One medical person said, "Never heard of it." But it is way too common out there.
Once you get the spore in your lung, and you heal, it will always be there. I know because a relative of mine got Valley Fever. So, what are they doing out West in the air is anybody's guess, but if I lived there I'd sure try and find out.