It is interesting that there is a link between military service and ALS, but an even higher risk if you were in the airforce. When Tim was at the VA in Seattle for his first assessment he met a Vet with very severe MS. After talking to him we discovered that he was in his late 50's and that 80% of the guys in his squadron were either dead or had MS. He said that he was in the airforce and was responsible for de-icing planes, and that they had identified the chemical that caused all the problems. I'm sorry I can't remember what it was, but Tim was the fuel chief and was around all the jet fuels, and of course de-icers. Aside from the vaccinations that he got initially when he enlisted he has refused any others. He worked in landscaping for a period in his life, but used organic pesticides that he made himself with soap, and tobacco or something like that.
As a nurse I have had a lot of vaccines, and a flu shot every year as required by my work. I have done missionary work, so had all the shots for tropical places. The reason that I mention this, is that nurses receive vaccines regularly, and if ALS had a link to them, I think we would hear of a lot of nurses getting it.
Genetics could play a part of course, but Tim's comes from a very large family that has a long history of military enlistment, and he is absolutely the only person from his family, or relatives for many generations with any neurological condition at all. It is all so frustrating