May 22, 2009
Bisphenol A, a chemical found in plastic water bottles, leaches from the bottle and ends up in the urine of people who drink from them, say researchers at the Harvard School of Public Health.
The researchers found that study participants who drank for a week from polycarbonate bottles, the popular, hard-plastic drinking bottles and baby bottles, showed a two-thirds increase in their urine of the chemical, also known as BPA.
Exposure to BPA, used in the manufacture of polycarbonate and other plastics, has been shown to interfere with reproductive development in animals and has been linked with cardiovascular disease and diabetes in humans, the researchers said.
The study is the first to show that drinking from polycarbonate bottles increased the level of urinary BPA, and thus suggests that drinking containers made with BPA release the chemical into the liquid that people drink in sufficient amounts to increase the level of BPA excreted in human urine.
The study appears on the Web site of the journal Environmental Health Perspectives.
In addition to polycarbonate bottles, which are refillable and a popular container among students, campers, and others, and are also used as baby bottles, BPA is also found in dentistry composites and sealants and in the lining of aluminum food and beverage cans.
Numerous studies have shown that it acts as an endocrine disruptor in animals, including early onset of sexual maturation, altered development and tissue organization of the mammary gland, and decreased sperm production in offspring. It may be most harmful in the stages of early development, the researchers said.
We found that drinking cold liquids from polycarbonate bottles for just one week increased urinary BPA levels by more than two-thirds. If you heat those bottles, as is the case with baby bottles, we would expect the levels to be considerably higher. This would be of concern since infants may be particularly susceptible to BPAs endocrine-disrupting potential, said Karin B. Michels, associate professor of epidemiology at HSPH and Harvard Medical School and senior author of the study.
Because of a number of studies suggesting that BPA is harmful to humans, Wal-Mart and several other retailers have stopped carrying infant formula bottles made with BPA. However, the Food and Drug Administration holds that small amounts of the substance are not harmful.
Recent published reports suggest the FDA relied heavily on the advice of chemical industry lobbyists in reaching that conclusion.
Harvard Study Raises BPA Concerns...