You mentioned the chemical factory. I father in law worked as a printing press techician and was exposed daily to polychorinated biphenyls (PCBs), which were banned from production in 1979. He died of multiple myeloma, and there were suspicions at the time that PCBs might have caused it. Unfortunately, I think he passed the cancer gene onto my wife who got a GBM eight years ago and died six years ago. I miss her terribly, by the way. Now I have a son who looks just like his mother and he has a Grade II anaplastic astrocytoma, with a poor prognosis.
I would not be surprised if the work at the Chemical Factory was a major factor in his getting cancer, especially if he was exposed to PCBs. Transformers and like equipment manufactured before 1979 are still out there and the general public is at risk, albeit minimal because there is not likely to be that much equipment manufactured before 1979 still in use.
I will pray for your husband and the sooner you have the operation and find the right chemo to kill the remaining tumor cells, the better.