There will quite possibly never be a last word on the health effects of bisphenol A, also known as BPA. The chemical is widely used in plastic bottles, cans and even on cash register receipts and has been linked in some studies with potential longterm health consequences in humans.
But the latest -- if not the last -- word comes from a toxicologist who examined 150 previous studies involving 30,000 people in 19 countries and found the exposure levels generally much too low to have any impact.
Justin Teeguarden, a senior research scientist at the Department of Energy laboratory in Richland, Wash., presented his findings at a recent meeting of the American Association for the Advancement of Science. His study was funded by the Environmental Protection Agency (EPA).
Teeguarden said the levels he found were "thousands of times lower" than levels that cause health effects. Teeguarden's findings lend support to the assertions of the American Chemistry Council and other industry groups that have long argued that human exposure to BPA is so slight that it is inconsequential.
"Safety assessments of bisphenol A (BPA) conclude that the potential human exposure to BPA from polycarbonate plastics and epoxy resins is more than 400 times lower than the safe level of BPA set by the U.S. Environmental Protection Agency. This minimal level of exposure to BPA poses no known risk to human health," the council says on its website.
Supports earlier findings
It's not the first time Teeguarden's research has found no significant ill effects from exposure to BPA.
In a study published in the leading toxicology journal, Toxicological Sciences, in 2011, also funded by the EPA, Teeguarden tracked bloodstream and urine levels of BPA in volunteers who are a lot of canned food over a 24-hour period.
“In a nutshell," Teeguarden said in a July 2011 Forbes article, “We can now say for the adult human population exposed to even very high dietary levels, blood concentrations of the bioactive form of BPA throughout the day are below our ability to detect them, and orders of magnitude lower than those causing effects in rodents exposed to BPA.”
Teeguarden’s findings show “the majority of effects observed in animal studies are probably not relevant to humans because they involved much higher BPA exposures,” Professor Richard Sharpe, Principal Investigator at the Independent Medical Research Center’s Center for Reproductive Health in Britain, was quoted as saying in the Forbes article.
Teeguarden, who receied his Ph.D. from the University of Wisconsin, has worked in toxicology since the late 1980s, with much of his work involving the "relationship between external exposure, target tissue dose and response," according to his DOE staff profile.
Questions remain
BPA is used to harden plastic and prevent the growth of bacteria in food packaging products. Some researchers have expressed concern that it can interfere with the body’s hormone system, potentially leading to a variety of health problems, including damage to the reproductive system and the brain, particularly in children.
Eleven states have banned the chemical’s use in certain products, typically baby bottles and other children’s goods; Canada, China and the European Union have similar restrictions.
A study released last year found that an unborn child exposed to BPA can be at increased risk of lowered thyroid function. The findings were based on a study of newborn sheep.
Last summer, the Food and Drug Administration (FDA) banned BPA in baby bottles and sippy cups but said it is safe in other applications. The National Toxicology Program at the Department of Health and Human Services, however, says it has "some concern" about the possible health effects of BPA on the brain, behavior and prostate gland of fetuses, infants and children.
What to do
If you have concerns about the safety of BPA, here are some steps listed by Katherine Zeratsky, a Registered Dietician at the Mayo Clinic, to minimize your exposure:
- Look for BPA-free products. Unless labeled otherwise, most aluminum cans and bottles are lined with BPA, while steel bottles and cans aren't.
- Microwave carefully. Over time, polycarbonate plastic -- the kind with a No. 7 recycling symbol -- can break down, possibly allowing BPA to leach into the food.
- Wash plastics by hand. Zeratsky notes that the National Toxicology Program advises against washing polycarbonate plastics in the dishwasher, although the American Chemical Council says it's safe to do so.
- Use something else. Use glass, porcelain or stainless steel instead of plastic for hot food and liquids.
- Use less canned food. Many cans are lined with BPA.
There will quite possibly never be a last word on the health effects of bisphenol A, also known as BPA. The chemical is widely used in plastic bottles, can...