I worked construction and plant shutdowns when I was young. By the time I was in my mid twenties I had quit and went in to IT. The reason was simple. During my time in a union over ten of the old timers had died of cancer and other related illnesses. Only one of them was in their sixties. Over half were under forty. One of the best friends I will ever have died when he was fifty four. A month or so shy of when he was going to take early retirement.