This is an intriguing paper. See Table 2.
High levels of BMAA were found in the brains of
people with ALS and AD, but none was detected
in all but a very few controls.

http://tidenetwork.org/wp-content/up.../Bradley-1.pdf

BMAA is a toxic amino acid produced by cyanobacteria
(blue-green algae). Cyanobacteria occur in massive
blooms in both freshwater and sal****er, as recently
occurred in Lake Erie. They also are common soil
bacteria, so may present a risk in agricultural crops,
though the major route of exposure for people is
contaminated drinking water. BMAA was present in 90%
of blue-green algae species tested.

http://www.serrano.neves.nom.br/lsm/...e/ciano_02.pdf

This seems like a good reason not to drink tap water.
I wonder if we'll see an epidemic of ALS and Alzheimer's
in Toledo in a few years.

http://www.accuweather.com/en/weathe...harmf/31210317