Drinking cold beverages out of polycarbonate bottles significantly increases the concentration of bisphenol A found in a the body. Researchers from Harvard University and the U.S. Centers for Disease Control and Prevention found a 70% increase in the amount of BPA detected in the urine of college students who drank from plastic bottles made with BPA.
The study was published in Environmental Health Perspectives, the journal of the National Institutes of Environmental Health Science.
The researchers recruited 77 Harvard College students to participate in the two-week study.
During the first week, the students were "washed out:" They drank cold beverages only from stainless steel containers, and were asked to avoid the polycarbonate cups provided in the college dining halls.
The following week, the students were provided with two polycarbonate bottles, which they were told to use for all cold drinks.
Researchers collected four urine samples from each student; two during the final days of the wash out, and two during the plastic bottle week.
The average levels of BPA found in urine jumped by 69% between the first and second week.
There was a "measurable increase in urinary BPA resulted from only one week of exposure to beverages contained in polycarbonate bottles," wrote the authors in their study.
This was the first time researchers had looked for the effect of polycarbonate drinking bottle use on urinary BPA concentrations.