Cyanosis is the medical term is but I should clarify its not like their skin was purple all the time. What happens is that if you drink a lot of the polluted well water then when your veins narrow (like from cold) it gets a more purplish hue. This happens naturally (like when your lips are cold after swimming) but its just more noticeable if you are drinking polluted well water from farming runoff.

A thing kids would do at my school is stick their hand out the window of the bus in the fall/winter and then compare whose hand is "more purple". Dumb kid stuff. I still remember a single person I knew whose cheeks would be super purple every time we came inside from playing in the winter. Almost like the character in the willy wonka movies.

So like its well known the color is simply more noticeable when you are being constantly exposed to nitrates. The person I am thinking of -- he was almost certainly drinking bad well water at home, perhaps for his whole life. I can't imagine that was only from the fountains at school. As far as I know its not a huge deal but like the article is saying... it quite obviously has knock on health effects.

The short answer is nitrate poisoning. It usually happens in infants before it hits adults. The reduction in water volume in the aquifer is reducing the dilution of existing nitrate contamination from agriculture.

From the article:

> Morrow County, Oregon, has recorded nitrate readings as high as 73 parts per million (ppm) in household wells—more than ten times the state’s legal ceiling of 7ppm—following reports that local data centres are intensifying aquifer contamination.

From the CDC:

> The first reported case of fatal acquired methemoglobinemia in an infant due to ingestion of nitrate contaminated well water in the United States occurred in 1945 [Comly 1945]. This condition is also termed “Blue Baby Syndrome”.

https://archive.cdc.gov/www_atsdr_cdc_gov/csem/nitrate-nitri...