Lee ~
I have no idea what caused the genetic mutation that produced your ex-husband's AN - or yours - and I haven't read/heard about this happening on any kind of regular basis.
The issue of environmentally-caused cancers (or benign tumors) has been around a long time. Over the years, I've seen a host of things branded as 'causing' tumors both benign and malignant. Some are purely speculative but some are later proven carcinogens. Lately, cell phones have been targeted by some as a potential cause of cancer and, specifically, acoustic neuromas. I'm a firm skeptic on that one but there is no doubt that our environment often can (and does) increase our chances of developing tumors, be they benign or malignant. The problem is that, too often, with these suspected environmental dangers, we never seem to know for a fact what is actually dangerous and what just seems to be suspect due to weird, admittedly dubious coincidences. It's frustrating. We can't live in a cocoon and yet, no one wants to take unnecessary, avoidable risks, especially where tumors are concerned. Unfortunately, I don't have a solution but the question is certainly germane. Frankly, in your case, moving to another neighborhood might be a prudent course of action.
Jim
