Football players also have a 4x increased risk: https://tulsaworld.com/lifestyles/ask-the-doctor-pro-footbal...
But basketball players don’t - go figure.
Stephen Hawkins spent ca 1000h on boats during his college years (interesting since you mentioned that streams might bear some trigger)
In the set you presented. The only people who have increased risk of ALS are those that play sports on grass fields. Maybe that's the key? Grass.
https://www.cbsnews.com/newyork/news/ticks-lyme-disease-cdc-...
Lots of anecdotal evidence of ALS developing after tick bites, or more concretely infection with Borrelia Burgdorferi.
Probably a genetic component, and other enviromental factors are also involved, but the only dramatic reversals of MND I have seen documented (or heard about) have been either with IV antibiotics [1][3], or years of Mercury chelation [2]
[1] https://invisibledisabilities.org/award-recipients/2011award...
[3] https://pubmed.ncbi.nlm.nih.gov/17212618/
[2] https://www.researchgate.net/publication/317849075_Healing_o...
In the recent book "Chronic" by Dr. Stephen Philips, he's frustrated since he can only treat successfully (outcome similar to Dr. Martz), with antibiotics, about 15% of his ALS-like patients. Considering how uniformly fatal ALS diagnosis is otherwise, even considering how skewed of a sample he might get (patients that already know they are Lyme positive or suspect it), still find it astonishing.
https://storelli.com/blogs/the-storelli-blog/soccer-concussi....
https://journals.lww.com/cjsportsmed/Abstract/2001/10000/Con...
From the first link, here is the ranking of concussion rate:
1. Rugby (4.18/1,000 AE) 2. Ice hockey (1.20/1,000 AE) 3. American football (0.53/1,000 AE) 4. Lacrosse (0.24/1,000 AE) 5. Soccer (0.23/1,000 AE) 6. Wrestling (0.17/1,000 AE) 7. Basketball (0.13/1,000 AE) 8. Softball & field hockey (0.10/1,000 AE) 9. Baseball (0.016/1,000 AE) 10. Cheerleading (0.07/1,000 AE) 11. Volleyball (0.03/1,000 AE)
> Athletic Exposure (AE) is defined as one athlete participating in one game or practice.
Possibly infection when being looked at for a head injury, but I assume they take decent precautions.
Another user proposed grass was the commonality between those sports, in that case grass/dirt entering the eyes?
For forest/streams, possibly water/dirt entering the eyes?
Doesn't really narrow much down though, avoid all dirt, grass, and water.
I think the Borrelia Burgdorfferi hypothesis would fit better, with Lyme disease numbers climbing in recent decades.