Environmental connections to public health >>
On BPA: How Risky? How Much Concern? When to Act?
Special to Enviroblog by Elizabeth Grossman, who writes about environmental and science issues from Portland, Oregon and is author, most recently of Chasing Molecules.
On January 22, in a substantial shift in policy, the U.S. Food and Drug Administration announced it has "some concern" about the health effects of bishphenol A (BPA), particularly on infants and children. While not currently advocating regulation, the FDA is proposing steps that could lead to restrictions.
"We need to know more," said FDA Commissioner Margaret Hamburg during a press conference. But "as a precaution," the FDA has issued recommendations for reducing exposure.
This contrasts markedly with the FDA's 2008 assessment that declared of BPA use safe in consumer products, including for infants and children. It also aligns FDA's views with those of the National Toxicology Program and National Institute of Environmental Health Sciences.
Bisphenol A is the chemical building block of polycarbonate plastics. In use since the 1950s, polycarbonates go into countless consumer products, including baby bottles, sippy cups, food containers, dishware, appliances, electronics, shatterproof lenses, and sports gear. BPA also makes the epoxy resins that line most food and beverage cans, and jar lids. BPA has numerous additional applications, including dental sealants. It is used so widely that scientists consider exposure ubiquitous and continuous.
"We know that trace amounts of BPA can be found in these [food] containers," said William Corr, Deputy Secretary of Health and Human Services. "Recent reports of subtle effects of low doses of BPA on lab animals has raised concerns," said Corr, "that we need to take a closer look at."
It's well documented that as these plastics age, are heated, or are used with acidic or alkali liquids - from certain vegetables, fruits or detergents, for example - BPA can leach out of finished products. Biomonitoring studies conducted by the Centers for Disease Control has found BPA in over 90% of Americans tested. Studies published in 2009 found BPA in newborns' umbilical cord blood and in 75% of the infants being cared for in a hospital's neonatal unit.
Concern arises because BPA is known to be an endocrine disrupting chemical. In numerous animal studies BPA has been shown to interfere with hormones that regulate reproduction, development, metabolism, and behavior.
"There are critical periods of development when exposure to BPA may lead to certain health effects, including behavioral effects, diabetes, reproductive disorders, development of certain kinds of cancers, asthma, cardiovascular disease, and effects that can go from one generation to the next," explained Linda Birnbaum, director of the National Institute of Environmental Health Sciences.
Although hundreds of published studies now document such effects, they remain controversial from a regulatory perspective in part because low-dose effects challenge traditional dose-equals-poison tenets of toxicology. Birnbaum and Corr cited the need for more research to determine the human health effects of BPA. To this end the NIEHS recently announced $30 million to fund new BPA studies.
In the FDA's announcement, Deputy Commissioner Josh Sharfstein said the agency would like to move BPA into a new regulatory framework that would allow the agency to respond quickly if it feels more research or regulation is required. "We would like to have a more robust framework for regulating BPA if and when necessary," said FDA Commissioner Margaret Hamburg.
In response, the American Chemistry Council (ACC), the trade association representing bisphenol A manufacturers, noted the lack of definitive proof of BPA's harm to human health. "While ACC recognizes that HHS and FDA are attempting to address public confusion about BPA we are disappointed that some of the recommendations are likely to worry consumers and are not well-founded," said the ACC.
THE FDA announcement came on a busy week for BPA news. A new study released on January 13th confirmed findings of a previous Journal of the American Medical Association paper showing an association between bisphenol A exposure and cardiovascular disease. Analyzing data from the CDC's biomonitoring studies, researchers in the U.K. found that individuals with the highest BPA exposure had a 40 to 50% higher reported incidence of heart disease.
While this study does not prove BPA can cause heart disease, explains co-author Tamara Galloway, professor of ecotoxicology at of the University of Exeter, it shows that coincidence of exposure and cardiovascular disease is not "a statistical blip." Galloway and other researchers point out that the study only examines a "snapshot" and more information is needed to produce a comprehensive picture. But, says Galloway, "It adds a lot of realism" to earlier findings and underscores the need for further research.
Despite its limitations this study does begin to suggest that BPA may be a "systemic toxicant" - one that can adversely affect a broad range of vital body systems, says Bruce Lanphear professor of children's health at Simon Fraser University.
When a pattern of toxicity begins to emerge, says Lanphear, "We have two options as a society. We can wait until we're swamped by the evidence to decide if we should allow continued use or we can act without waiting for crises."
Such decisions are now before state legislators in Washington and Oregon considering bills that would restrict the use of BPA in children's products. Connecticut, Maine, Chicago and Suffolk County, New York have adopted such legislation. Many other states have introduced comparable bills, and Sen. Diane Feinstein (D-CA) has introduced federal legislation that would restrict BPA in all food containers.
In hearings held in Olympia and Salem on January 11 and 13th, ACC representative Steve Hentges, told legislators that BPA "is not a risk to human health, including infants and children" and questioned the need for legislative action "given intense ongoing federal regulatory agency review."
At the Oregon hearing, North American Metal Packaging Alliance representative William Hoyle, described BPA epoxy resins as vital to food safety, stressing that viable, reliable alternatives are unavailable. Some alternatives do exist, however, and are being used by U.S. and Japanese manufacturers.
On Friday the FDA announced it would actively support research and development of BPA alternatives. "We will facilitate the development of alternatives, particularly for infant formula and food can liners," said Commissioner Hamburg.
Meanwhile, manufacturers are not waiting for regulation. The six baby bottle manufacturers, representing most of the U.S. market are already phasing out their BPA-based products. Meanwhile, major retailers, including Wal-Mart and Target, are offering increasing numbers of alternatives.
For now, it's largely up to consumers to decide whether or not they feel comfortable using BPA products. The FDA does not recommend families change what or how they feed their babies, but it does recommend reducing BPA exposure by using alternative baby bottles.
The FDA's January 15 BPA recommendations are open to public comment for 60 days. Timing was not specified but the FDA does plan to update its formal 2008 assessment. A "chemical action plan" on BPA is also expected from the EPA.