Lets not be naive about factory jobs. Yes, there are clean factory jobs, but many of them are dirty. Most industrial processes give off some sort of waste and byproducts. The list starts with air born particles from handling the materials (via grinding, polishing, heating, etc.) to solvents and chemicals used to process the products. EPA guidelines are limited and often discount the cumulative effects of multiple byproducts. Even common stuff like a little bit of unburned hydrocarbon and gas additives are not healthy. Now, over times, thus accumulates in your system, and our medical procedures are not advanced enough to properly attribute a cause and effect in many cases. I used to work in an exotic chemicals lab where we had in stock lots of synthetic chemicals on hand. We use to joke around that if someone was exposed, we could sooner describe the quantum chemistry rather than suggest a cure. Also, most of us have dealt with blue collar workers. Yes, some are nice and genuine, but most would kick the shit out of you just for a joke. They know that most educated folks don't want to be in their position and resent you for that. As a child, I used to live in Wisconsin, cheese and paper mill country. Most of my classmates were junior thugs. Even though everyone in my school was of White European descent (mostly Germanic), I saw so many cases of school bullying because some did not fit in. I heard that the same thing happens on the job.