A bit of poking around later … (because I had been taking some Manganese to help with some bone problems. The recomended intake is maybe 1.5mg/day (adult male, more for pregnant women)). The toxic level is around 11mg/day. Among other things it can be neurotoxic. So it has pretty tight margins, similar to, say Fluorine. See links from the wikipedia article.
>(EY) You get all the manganese you need from ordinary drinking water, if it hasn’t been distilled or bottled.
A bit of poking around later … (because I had been taking some Manganese to help with some bone problems. The recomended intake is maybe 1.5mg/day (adult male, more for pregnant women)). The toxic level is around 11mg/day. Among other things it can be neurotoxic. So it has pretty tight margins, similar to, say Fluorine. See links from the wikipedia article.
>(EY) You get all the manganese you need from ordinary drinking water, if it hasn’t been distilled or bottled.
This really depends. Amounts in drinking water vary wildly from hardly any to far too much. Brown staining on porcelain is one sign that your water is over 0.5mg/Liter, and the taste becomes ‘undesirable’ at that point too. See https://www.waterra.com.au/publications/document-search/?download=542
and “Intellectual Impairment in School-Age Children Exposed to Manganese from Drinking Water” on researchgate.net (LW mangles the URL sorry)
Groundwater or runoff water affected by pollution seems to make it much more likely Mn is too high.