By Nadia Mangialetti, Ph.D.
Posted: Thursday, June 27, 2002
ARTICLES
Publication Date: June 27, 2002
Earlier this year, an anonymous e-mail confronted many online readers with a frightening proposition: that they are slowly poisoning themselves with toxic chemicals every time they microwave food in a plastic container.
The source of this warning can be traced to Edward Fujimoto, manager of the Castle Center for Wellness and Lifestyle Medicine in Hawaii. Fujimoto, a doctor of public health, subscribes to a better-safe-than-sorry philosophy regarding using plastic containers in the microwave oven. "If you're not sure about that, you just stay away from it," he says. "Because when the evidence comes in, that'll be too late."
Fujimoto claims that plastic containers including those labeled "microwave safe" contain cancer-causing dioxins and other endocrine-disrupting chemicals, which leach out into food. However, the Food and Drug Administration finds no evidence to support this claim and says that plastic containers do not even contain dioxins in the first place. Several websites that debunk urban myths and hoaxes also dispute Fujimoto's claim.
Fujimoto initially presented his case on KHON-TV, a local Fox affiliate in Honolulu, on January 23. Someone probably a viewer subsequently composed an e-mail about it and within a few days an exponential flood of forwarded e-mail glutted the Internet. An "amazed" Fujimoto found himself getting phone calls from all over the globe.
That Fujimoto never gave any evidence for his damning claim does not seem to have bothered many people. Instead, debate what little there has been of it has questioned the wisdom of relying on an anonymous, unsolicited, forwarded e-mail for health information.
Now, Fujimoto says that he bases his claim on research done in Japan and available only in Japanese. According to him, dioxins and plastics are a "hot topic" in Japan, as demonstrated by a conference in Tokyo on "The Toxicology and Effects of Plastic Containers," sponsored by the Japanese Ministry of Health, in 1997.
The concern in Japan was sparked, he says, by the finding that "plasticizers were leaching out of the cafeteria utensils that the kids used in schools for lunch." One study, he reports, found that the more often plastic tableware was washed (autoclaved, in the case of school cafeterias), the more a dioxinlike chemical leached out.
Fujimoto says that Japanese research shows that dioxins and dioxinlike compounds, such as phthalates and bisphenol-A, as well as "thousands of other endocrine disrupters," leach out at temperatures as low as 120 degrees Fahrenheit. They are more often found in clear plastic than in cloudy or opaque plastic, he says. Fujimoto says that American-made plastic containers are no different from the kind that used to be made in Japan and Germany. "They use polycarbonates here in the U.S," he says. "In Germany they banned polycarbonate bottles for human beings." The Japanese government, he says, has stricter standards for the amount of chemicals that are allowed to leach out of plastics than either the European Union or the U.S., which, for some chemicals, has no standards at all.
Fujimoto says that the Japanese attribute neurological, behavioral, immune system, fertility, and hormonal problems, at least in part, to dioxins and other endocrine disrupters leaching out of plastic containers.
When asked directly whether anyone had measured the amount of dioxins or other chemicals in different foods and in different types of plastic containers before microwaving, and then measured them again after microwaving, he said, "I think someone must have done something. I haven't seen it."
Fujimoto had a hard time coming up with the specific Japanese articles from which he got his information. Saying that "they" have done research or "they" do this or that in one country or another, without being able to cite references, is tantamount to relying primarily on hearsay. Merely pointing to an authority even a government authority doesn't mean that a belief is scientifically valid.
When pressed, Fujimoto was finally able to name a few publications, which, he said, contained relevant articles, and a few scientists who, he said, had conducted relevant research. But he did not seem to know the complete citations (journal, title of article, author's name, month, year, volume, page) so that an interested party could find them. Some of the studies he spoke of examined "tin" cans or Styrofoam cups, not plastic containers as if these were all the same. To speak so passionately about something and yet not have, at one's fingertips, the references that underlie one's claims warrants skepticism.
Regarding plastic containers that are specifically designed and labeled "for microwave use," Fujimoto says, "I don't think they're safe." He believes that these containers are tested only to assure that they will not melt or shatter in the microwave oven not whether they leach any substances from the plastic into the food. Again, he presents no studies showing that "microwave safe" containers do that.
Granted, measuring dioxins and the other chemicals in question is not a simple matter. According to the World Health Organization, only about a hundred laboratories worldwide are equipped to detect them, and the cost is often prohibitive (around a thousand dollars per sample). Still, to make sweeping statements about dozens of different plastic container products without having made such measurements is to engage in unsubstantiated, non-scientific over-generalization.
The amounts of dioxins and dioxinlike chemicals that may leach out are infinitesimal on the order of "trillionths of a gram," according to Fujimoto. While the FDA and other critics of Fujimoto's claim dismiss such small amounts as inconsequential, Fujimoto says that the body does not excrete these toxins and "because you have thousands of them, they all accumulate in the body and they have a synergistic, a cumulative type of effect." It is true that dioxins are chemically very stable and have long half-lives (on the order of eight years). But Fujimoto presents no data showing that they accumulate in the body or whether and how much they might interact synergistically.
"I've been accused of lying," Fujimoto laughed, when confronted with the paucity of data to support his claims. That's a bit strong. He appears sincere in his belief. But even highly educated health professionals sometimes believe plausible-sounding ideas that have little more behind them than appeals to authority or second-hand summaries of about research that "they" have done.
Jeff Richards, author of Hoaxinfo.com, wrote: "I was able to find some evidence that certain chemicals could leach into fatty foods from some kinds of plastics. However, I could find no studies that indicated that dioxin was one of those substances...It is true that some plastics release dioxin when they are incinerated. However, burning plastic requires much higher temperatures than you get in a microwave. I don't think you can jump to the conclusion that because dioxin is formed at high temperatures that some must be released or formed at much lower temperatures. Interestingly, I did find several studies that indicated certain kinds of dioxins were actually reduced by cooking, even in a microwave. Fatty foods are one of the most likely places to find dioxin [emphasis mine]. It is generally consumed by an animal and it concentrates in the fatty tissues of the animal who ate it. You seem far more likely to get more dioxin from eating under-cooked meat than from heating anything in a butter tub."
One chemist at the FDA's Center for Food Safety and Applied Nutrition who spoke to me categorically denies that there are any dioxins in plastic containers. He told me "there is absolutely no basis" for this claim. But the FDA is open to new information in English. The agency "will pay for a translation if there is reason to believe it is sufficiently important to protect public health." The FDA chemist says his agency is "interested in seeing specific documents related to this [dioxin in plastic] to properly assess such a claim. If there are 'thousands of endocrine disruptors,' surely they can be named. If there are dioxins known to be in plastics, someone must have analyzed for them and have data that can be reproduced by others."
"Dioxin is found in nature," the FDA chemist explains. It is present in the environment in very low levels everywhere, as it is produced by fire, by bacteria, and probably by other natural, yet-to-be-discovered processes. Dioxins are also byproducts of various industrial, chemical, and manufacturing processes and are released during trash incineration. However, more dioxin exists in the environment than can be accounted for by human activity.
The FDA has regulatory authority over all plastic containers for food but focuses mostly on those sold with food in them (that is, as packaging) rather than on those sold empty (that is, as storage containers). The FDA "only steps into the latter when we identify a problem."
The manufacturers of plastic containers have a vested interest in keeping their products safe. During testing, containers are filled with a solvent such as water, alcohol or a liquid hydrocarbon, to simulate the major types of food that will be packaged or stored in them. Then they are heated to the maximum temperature that the consumer is later expected to use. Various measurements are taken at different points in time, up to six months later. Separate standards apply, depending on whether the intended food is dry or wet, water-based or fatty-based, served cold or hot (and how hot).
The FDA chemist says that plastic containers might contain low levels of compounds other than dioxins. "Our regulations contain many pages on ingredients in plastics that have been found to be safe in foods, under the conditions of use." According to him, all plastics leach a little bit of whatever is in the plastic when heated, and the higher the temperature, the more the leaching. Some leaching may occur even at refrigerated temperatures. The issue for food safety is not whether leaching occurs, but how much of what leaches over what period of time.
"Microwave-safe" plastic containers have a higher melting point than other plastics one that is not likely to be reached in a microwave oven. The FDA warns that other plastic containers not specifically labeled "micro-wave safe" should not be used in the microwave oven. "It is impossible to comment on [their] safety because they haven't been tested under those conditions," the FDA chemist says.
So, what to do when the experts disagree and when one of the experts not only claims to have evidence written in a language that the other experts can't read but can't even tell them where to find these reports?
For now, the consensus seems to be: Use common sense.
Don't microwave leftovers in plastic margarine tubs, deli food containers, yogurt cups, whipped topping containers, or any other storage containers that are not explicitly labeled "for microwave use." Use a "microwave safe" glass or ceramic container instead.
If you decide to avoid microwaving even those containers labeled "microwave safe," realize that, at this point in time, you are doing this more for your own peace of mind than for any scientifically valid reason.
Meanwhile, the rest of us will continue to enjoy the convenience of "microwave safe" plastic containers unless and until evidence to the contrary is made available and subject to scrutiny.
References:
Jeff Richards, M.A.
(author of one of only two sites that were critical of the forwarded e-mail)
http://hoaxinfo.com/toxicplastic.htm
richards@iname.com
http://www.breakthechain.org/exclusives/dioxins.html
Marshall Brain
How Microwave Ovens Work
http://c1.zedo.com//ads2/f/8856/3853/172/0/152005744/152000000/0/152/48/zz-ad4_720x300.html
brain@howstuffworks.com
Barbara Mikkelson
http://www.snopes2.com/toxins/plastic.htm
http://www.truthorfiction.com/rumors/dioxins.htm
World Health Organization
http://www.who.int/inf-fs/en/fact225.html
For further information, journalists can contact:
WHO Press Spokesperson and Coordinator, Spokesperson's Office,
WHO HQ, Geneva, Switzerland
Tel +41 22 791 4458/2599
Fax +41 22 791 4858
inf@who.int
Nada Mangialetti, Ph.D., is a freelance science writer and psychologist, and a lifetime member of the New York Area Skeptics.
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| Responses:
July 1, 2002
In the article about dioxins from microwaved plastic containers, it is intimated that this substance is more likely to be found in uncooked meats and especially in the fat of the meat. I regularly consume meat and fat uncooked and find that it has a positive health benefit without, as yet, any known health hazard; that was until I read this article. I understand, for example, that parasites can exist in uncooked meat but that it becomes safe if frozen for over fourteen days. Is there any known hazard in eating uncooked meat and fat that I'm ignorant about? Is there anyone knowledgeable on this topic who can competently provide advice?
Robert Park
Kirriemuir, Scotland
July 29, 2002
A science project by a student in the US ostensibly fueled the fire of concern about plastics leaching harmful chemicals (DEHA carcinogens specifically).
I have asked the American Petroleum Institute and the Society of Petroleum Engineers to comment, and they keep referring to the Fujimoto position, which is generally not based on any science. I have advised them they should deal with this issue from an industry standpoint, as we in the plastics industry do not need any more negative publicity.
They have not replied.
R.E. Cook |
