I listened to this podcast (https://radiolab.org/podcast/lithium) a while back and Lithium in groundwater was linked to lower suicide rates, less felonies. Lithium is used to help bipolar people keep their moods from having drastic swings. Here's a map if you want to live in an area where your neighbors are medicated whether or not they want to be medicated...* *Caveat: Only applies to areas that use groundwater as a drinking water source.