Leo Trasande

Last summer NBC told viewers bottled water was bad for the environment because of its packaging and transportation demands.

This time, NBC's April 9 "Today" warned viewers some reusable water bottles are bad for society because they contain a dangerous substance.

"[M]any of those sturdy, reusable plastic bottles contain a chemical, bisphenol-A, that many scientists are worried about," NBC correspondent Michelle Kosinski said.

What did "Today base these concerns on? They based them on a study with lab rats given doses of biphenol-A "thousands" of times higher than what exists in the bottles.