Storing cheese in the refrigerator does not usually evoke comparisons to hazardous experiments with toxic chemicals. Recently, though, scientists and consumers have raised many concerns about the potential for chemicals in plastics to leach into foods, and whether this exposure can harm peoples' health. Considering the ubiquity of plastics in the kitchen, whether the refrigerator or the microwave, many consider it a significant health issue. Public and scientific awareness of the real danger is marked by myth, fact, and uncertainty.
Let's begin with what is patently untrue.
Recently, a widely circulated hoax e-mail, falsely attributed to Johns Hopkins University, claimed that putting plastic water bottles in the freezer - a common ritual for many people before exercising - released dioxins, a group of chemicals known to cause liver damage and cancer. According to Dr. Rolf Halden, assistant professor at John Hopkins, such a notion defies basic science: Freezing actually works against the release of chemicals. Dioxins remain a public health threat, but they primarily emanate from burning, such as the incineration of hospital waste.
Water bottles should not be absolved of all suspicion, though. Along with baby bottles, plastic cutlery, and the coating inside canned fruits and vegetables, they are commonly made from polycarbonate, a plastic derived from the chemical bisphenol A. According to Tom Natan, chemical engineer and research director of the National Environmental Trust, scientists once tested bisphenol A as a substitute for estrogen and introduced it briefly into the equestrian mating cycle. Animal experiments have since linked the chemical to an increased risk for reproductive malformations, and breast and prostate cancer at extremely low levels of exposure. "It takes very, very little `estrogenic chemicals` to cause harm," says Natan.
Ted Schettler, science director of the Science and Environmental Health Network, agrees that the use of bisphenol A in plastics is "a real health concern." In addition to heat, he says, the chemical can be released in contact with bleach. Schettler recalls a study conducted by Patricia Hunt at Western Reserve University, in which Hunt attempted to study chromosome development in rats. Someone corrupted the experiment, however, by washing the rats' polycarbonate cages with bleach: The rats ended up with "a bizarre number" of damaged chromosomes due to the release of bisphenol A from the cages. "The rats went haywire," says Schettler.
Storing food safely:
• Use glass or lead-free ceramics in the microwave.
• In general, wraps made of polyethelene are safer than those made from PVC.
• Never let plastic wraps touch food when microwaving. Loosen or vent the wrap to let steam escape, and discard wrap after single use.
• Do not put polycarbonate bottles in the microwave to warm milk or formula.
• Supermarkets and delis use PVC films to wrap meat and cheese . If you buy cling-wrapped cheese and meat, remove the film and wrap the food in something safer.
"It is well known that `DEHA` can migrate into fatty foods," says Marian Stanley, manager of the Phthalates Esters Council of the American Plastics Council. More hotly debated is whether this exposure can actually harm human health. According to Natan, DEHA been shown to cause liver damage in rats, and you don't have to heat the plastic wrap in the microwave to draw out the chemicals. "Even storing cheese in DEHA wrap, you're getting DEHA in the cheese," Natan says.
Stanley, along with the Food and Drug Administration, says there is no danger, a conclusion based on "extensive health and safety tests." The U.S. Environmental Protection Agency has removed DEHA from a list of toxic chemicals due to "insufficient evidence" that DEHA causes hormone disruption. Besides, says Stanley, "You would have to eat 1,500 pounds of cheese a day to get any substantial amount of DEHA."
The American Plastics Council calculated this number, which points to another controversial element in the DEHA debate: the tendency for the FDA to rely on industry data when determining the safety of "food contact substances." Another statement by the APC explains, "Companies that manufacture plastics conduct much of the testing on plastic packaging material."
"That's the problem with the FDA approach," says Schettler. "Science is always evolving, and policies should reflect the most current science." In a John Hopkins newsletter, Halden notes that "several European studies" found that chemicals in plastics absorbed into foods at "high quantities." "More research should be done in this area," he says. In the meantime, consumers may want to use Glad Cling Wrap and Saran Cling Plus Clear, which are both made from polyethelene and contain no plasticizers. Otherwise, as Natan points out, we are "the de facto guinea pigs." •