BPA Leaching into Liquids in Plastic Bottles

After a professor with the Harvard School of Public Health warned her students of the dangers of drinking too much water from hard plastic bottles because of exposure to a potentially dangerous chemical called bisphenol A or BPA, a research project was sparked to verify the concerns. BPA, a synthetic sex hormone that mimics estrogen and is used to make hard plastic can be found in hundreds of everyday products, such as plastic bottles, canned soup and infant formula. Concentrations of the chemical have been linked to an increased presence of diabetes, heart disease and liver toxicity. We now have confirmation that the liquid filling these plastic bottles absorbs enough of the chemical to register significant levels in the urine of those who drink the liquid.

According to researchers, the study sparked by concerns of a Harvard professor is the first to show that drinking from bottles containing BPA increases the presence of the chemical in urine. A team of researchers including associate professor Karin B. Michels, senior author of the report with the School of Public Health and Harvard Medical School, and Jenny Carwile, a doctoral student with the Harvard School of Public Health, recruited 77 Harvard students to participate in their study that exposed students to BPA from clear plastic polycarbonate bottles for a week. After the week of exposure, the students’ concentrations of BPA in their urine was 69 percent. The study results are published on the website for the journal Environmental Health Perspectives.

Carwile said, “While previous students have demonstrated that BPA is linked to adverse health effects, this study fills in a missing piece of the puzzle—whether or not polycarbonate plastic bottles are an important contributor to the amount of BPA in the body.” The Harvard team’s research was sparked in Michel’s class when she warned her students of the dangers of regularly drinking from hard plastic bottles because of the potential exposure to high levels of BPA. When the students then asked exactly what levels of BPA they were being exposed to, the study evolved. The Harvard students who volunteered to participate in the study all drank cold beverages from stainless steel bottles for a week to cleans their systems of any BPA, and they provided urine samples. For the next week students were given two refillable polycarbonate bottles with plastic containing BPA to use when drinking cold beverages. Urine samples taken during this week showed BPA levels had increased by two-thirds.

The results of the study is concerning because of several side effects that have been linked to over exposure to BPA and especially since majority of baby bottles are made from plastic containing the chemical.  BPA exposure in an animal study proved to interfere with reproductive development and in other studies involving humans the chemical has been linked to cardiovascular disease and diabetes. The newly released study is the first to identify that drinking polycarbonate bottles actually increases the level of BPA in the urine. Suggesting the chemical is released into the liquid, in bottles made with the chemical in ample amounts, to contribute to increased BPA levels in the urine. According to researchers the levels of the chemical in the students urine could have been even higher if they had drank hot drinks in the containers or exposed them to hot liquids or the dishwasher, which they refrained from doing. Studies conducted previously have shown leaching of BPA occurs when the bottles are exposed to hot temperatures.

According to Michels, “If you heat those bottles, as is the case with baby bottles, we could expect the levels to be considerably higher.” She added, “This would be of concern since infants may be particularly susceptible to BPA’s endocrine-disrupting potential.” As seen in a previously published article on our site, 95 percent of baby bottles sold contain BPA. The chemical is released 55 times faster than normal when the bottles are exposed to boiling water. While the FDA still says products that contain BPA are safe and exposure levels for both children and infants are still below levels that would affect ones health, Canada has already banned BPA usage in baby bottles and other states and governments are considering warnings or alternative measures.

Carwile said, “This study is coming at an important time because many states are deciding whether to ban the use of BPA in baby bottles and sippy cups. While previous studies have demonstrated that BPA is linked to adverse health effects, this study fills in a missing piece of the puzzle—whether or not polycarbonate plastic bottles are an important contributor to the amount of BPA in the boys.” Even though the FDA says it is safe, to me the newly released research raises new concerns, especially when infants and children are the ones exposed to the highest risks. There are a few steps to avoid additional exposure of BPA, such as hand washing bottles, avoiding harsh detergents or scouring bristles, not heating food in bottles, and avoid using infant formulas that come in containers lined with polycarbonates.