More evidence that BPA leaches from plastic bottles and into people.
Carwile, JL, HT, Luu, LS, Bassett, DA, Driscoll, C, Yuan, JY, Chang, X, Ye, AM Calafat and KB Michels. 2009. Use of polycarbonate bottles and urinary bisphenol A concentrations. Environmental Health Perspectives doi:10.1289/ehp.0900604.
A new study from Harvard University has found that urine levels of BPA are 69 percent higher after drinking cold liquids from polycarbonate plastic bottles.
Heating has long been known to enhance the migration of BPA from polycarbonate containers but this is the first study to show that urinary levels of BPA are elevated after drinking cold liquids. The report is another in a growing list of studies showing that food and beverages stored in containers containing BPA can become contaminated.
For this study 77 Harvard students drank cold liquids from polycarbonate bottles known to contain BPA for a week. BPA levels in urine samples collected at the beginning and end of this week were then compared. To minimize BPA exposure before the experiment started, students were given stainless steel bottles and asked to use those in place of plastic bottles for several days before the first urine samples were collected.
Compliance with this request was quite high. Urinary levels of BPA were 69 percent higher following polycarbonate bottle use demonstrating that BPA readily leaches from plastic containers, even when the contents are not heated.
The results from this study are consistent with the Center for Disease Control’s conclusion that more than 95 percent of Americans have BPA in their bodies, most likely the result of consuming BPA contaminated food and beverages.
BPA is found in a wide variety of household products most notably polycarbonate containers and the epoxy lining of aluminum food and beverage cans such as soda cans. Bottles with the number 7 on the bottom are polycarbonate and may contain BPA. BPA is also used to manufacture medical devices, compact discs, eye glasses, plastic water pipes and to line the insides of water storage towers.
BPA is an endocrine disruptor and can interfere with the action of hormones, including estrogen and thyroid hormones, in the body. High urinary levels of BPA have also been associated with chronic disease in humans including heart disease and diabetes.
Last year the Food and Drug Administration reaffirmed its position that BPA exposure does not pose a significant risk to human health. Despite this position, many polycarbonate bottle manufacturers including Nalgene and most baby bottle producers, voluntarily agreed to stop using BPA in their products. The Food and Drug Administration is preparing to evaluate the safety of BPA in medical devices, a process that will likely begin later this year.