It’s no secret that it’s recommended to keep well-hydrated by drinking at least 1.5 -2 liters of water daily, particularly in hot and dry conditions. But what if the bottled water itself has been exposed to hot conditions when left in the sun or in a car for hours? Americans can take a warning from a University of Florida study of bottled water in China ─ don’t drink the liquid if you’ve left it somewhere warm for a long time.
Cheryl Watson, a professor in the biochemistry and molecular biology department at the University of Texas Medical Branch in Galveston, advised people not to store bottled water in places that have a significant amount of heat, like a garage or a car parked outside.
“When you heat things up, the molecules jiggle around faster and that makes them escape from one phase into another. So the plastic leaches its component chemicals out into the water much faster and more with heat applied to it,” Watson told TODAY.
“It’s kind of like when you put mint leaves in your tea. The heat extracts the mint-tasting molecules and it happens faster in hot tea than it does in cold tea.”
If you’ve ever left a plastic water bottle in a hot car or another very warm environment for a while, you may notice the water tastes a little funny, Watson noted: “That’s everybody’s bottom-line sensing mechanism — you can even taste it,” she said.
Plastic water bottles are made from polyethylene terephthalate. When heated, the material releases the chemicals antimony and bisphenol A, commonly called BPA. While the U.S. Food and Drug Administration has said BPA is not a major concern at low levels found in beverage containers, it continues to study the chemical’s impacts. Some health officials, including those at the Mayo Clinic, say the chemical can cause negative effects on children’s health. And antimony is considered a carcinogen by the International Agency for Research on Cancer, part of the World Health Organization.
UF soil and water science professor Lena Ma led a research team that studied chemicals released in 16 brands of bottled water kept at 158 degrees Fahrenheit for four weeks, what researchers deemed a “worst-case scenario” for human consumption. Ma’s study found that as bottles warmed over the four-week period, antimony and BPA levels increased.
“If you store the water long enough, there may be a concern,” said Ma, an Institute of Food and Agricultural Sciences faculty member who has a research program at Nanjing University in China.
Watson, the University of Texas Medical Branch researcher, advised people to always stick to glass or stainless steel water containers — no matter the temperature. Those materials are very inert and don’t leach anything into the water, she said.
Her studies have found products labeled “BPA-free” may contain BPS instead, a chemical that’s very highly related to BPA in structure and appears to act much like BPA, causing the same disruptions of hormone signaling, Watson noted.
“More attention should be given to other drinks packaged with polyethylene terephthalate plastic, such as milk, coffee, and acidic juice,” she said. “We only tested the pure water. If it is acidic juice, the story may be different.”
BPA, which is used to make polycarbonate beverage bottles, food storage containers, metal can coatings, and which also coats some register receipts, has long caused concern about its impact on human health.
Ref. unknowncountry.com, MSN, Today, NBC News
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