In the mid-1980’s I did a television interview with Carl Decker, our Distributor with the local TV station in Fresno, California.
Fresno was close to the Kesterson National Wildlife Refuge, where in the early 1980’s the US Fish and Wildlife Service (USFWS) found a high incidence of mortality and deformities among newborn coots, stilts and ducks.
For several years prior to these findings only agriculture run-off water flowed into Kesterson. Further studies showed that several species disappeared from the refuge wildlife. These species had an intolerance to saline run-off water. After further studies, the USFWS concluded that selenium from subsurface drains from the farmlands of the San Joaquin Valley was the cause of the mortality and deformities of waterfowl at Kesterson.
On the other side of the ledger, selenium is an essential trace element and beneficial to the body in small amounts. So here is a case where a balanced perspective is important. We all need it in small amounts, but too much can be detrimental and in some cases has caused death (http://www.lenntech.com/periodic/elements/se.htm ).
As most people would not know how much selenium is in their drinking water (if any), my view is that it is better to drink distilled water which does not have selenium (selenium has a boiling point of 688oC) and take supplements with known levels of selenium needed for good health.
Incidentally, Carl Decker was a strong advocate of consumers using a distiller to remove such contaminants and for years, until his recent retirement Carl would talk to everyone he met about the benefits of drinking distilled water. That is one of the reasons why so many people in the Central Valley of California drink pure distilled water today.