[xilinx_guy]

you've hit upon a thorny problem. water testing services only test for obvious things like heavy metals, leaving organic contamination (i.e. drugs, industrial chemicals, etc) pretty much untouched. There are rather disturbing maps of American obesity levels that correlate well with river drainage basins. Reverse osmosis filtering is the answer, but you'll need to supplement to replace lost minerals like calcium, etc.

[reducesuffering]

I've considered the "lost minerals" angle, and from my research, I don't think it's an issue at all. The main significant minerals in tap water are Calcium, Magnesium, and Sodium.

"For half of the tap water sources we examined, adults may fulfill between 8% and 16% of their Ca2+ DRI and between 6% and 31% of their Mg2+ DRI by drinking 2 liters per day." from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1495189/

And another paper on calcium: "On an average basis this would represent 5% to 10% of the usual daily intake or approximately 6.5% of the adult RDA." from https://www.ncbi.nlm.nih.gov/books/NBK216589/

The calcium seems negligible. Magnesium is a top nutrient deficiency in Western diets, so could be somewhat negative, but because of that I (and probably you) should be supplementing magnesium anyway. Sodium is obviously found abundantly in western diets.

So based on that, I don't think re-mineralizing's tiny benefits are worth the potential risk of re-adding negative contaminants somehow.

[toomuchtodo]

Three stage whole house filters are about $500, sediment->heavy metals->carbon (with the ability to swap the post sediment filters for other cartridges targeting your water challenges). Throw in a UV filter for pathogens if cost is no object, and you might be able to avoid RO. Have to test the water to be sure what you should be filtering for. A quality lab water test runs $200-$300.

[treya]

I think this is mostly just correlation, and the more direct tie is in the economic demographic. River drainage basins generally go like this - the affluent demographic live on the upstream side of the city, the poor demographic live on the downstream side that's dirty and polluted after passing through the municipal area

[jollyllama]

Yep. Atrazine.

[algoatecorn]

correlation =/= causation.

But it does hint toward a potential linkage, which is our food system.

The areas you are thinking about are also: food deserts, low-income, and low education levels. All of which are stronger predictors of obesity.