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.
Unfortunately, there's no level of exposure that's been identified as being safe," Dr. Leo Trasande, a professor at the Mount Sinai School of Medicine, said in an interview with "Today" co-host Matt Lauer. "And, children and women of child-bearing age are especially susceptible."
Trasande told Lauer bottles with the chemical pose a threat when heated, washed or scratched. But according to the Polycarbonate/BPA Global Group Web site, those are all myths that have been debunked by scientific studies.
"Nevertheless, myths, misinformation and scare stories about polycarbonate bottles continue to circulate, in particular regarding real-life conditions of use that are claimed to result in the release of harmful levels of bisphenol A," the Web site says. "Several new studies from respected scientists and organizations are now available to clarify whether any of the myths are true and whether the scare stories have merit."