Friday, November 2, 2007

"This is an urban legend"

I finally found the report that I was looking for!

Some time ago I had a strong discussion with a colleague about cooling water in plastic bottles o warming food in plastic containers (specially designed for microwaves and so on...) into the microwave oven. He pointed that I was contaminating the microwave (or the water, but in that case the 'injured' would have been myself) with dioxins, and basically because of that everybody would get cancer.
Today, I received an email form a friend that was supporting his idea (bugger!)... but it looked like a spam. The good thing was that there where a reference to The John Hopkins University. I went to the JHU site and the report saying that the e-mail is spam was there to be read. Basically the issue of cooling water in plastic bottles or warming food in plastic containers is an urban legend, there are not scientific proves supporting that idea.

Part of the report:

Question: What do you make of this recent email warning that claims dioxins can be released by freezing water in plastic bottles?

Answer: No. This is an urban legend. There are no dioxins in plastics. In addition, freezing actually works against the release of chemicals. Chemicals do not diffuse as readily in cold temperatures, which would limit chemical release if there were dioxins in plastic, and we don’t think there are.

Question: What about cooking with plastics?

Answer: In general, whenever you heat something you increase the likelihood of pulling chemicals out. Chemicals can be released from plastic packaging materials like the kinds used in some microwave meals. Some drinking straws say on the label “not for hot beverages.” Most people think the warning is because someone might be burned. If you put that straw into a boiling cup of hot coffee, you basically have a hot water extraction going on, where the chemicals in the straw are being extracted into your nice cup of coffee. We use the same process in the lab to extract chemicals from materials we want to analyze.

If you are cooking with plastics or using plastic utensils, the best thing to do is to follow the directions and only use plastics that are specifically meant for cooking. Inert containers are best, for example heat-resistant glass, ceramics and good old stainless steel.

Question: Is there anything else you want to add?

Answer: Don’t be afraid of drinking water. It is very important to drink adequate amounts of water and, by the way that’s in addition to all the coffee, beer and other diuretics we love to consume. Unless you are drinking really bad water, you are more likely to suffer from the adverse effects of dehydration than from the minuscule amounts of chemical contaminants present in your water supply. Relatively speaking, the risk from exposure to microbial contaminants is much greater than that from chemicals.

And here’s one more uncomfortable fact. Each of us already carries a certain body burden of dioxins regardless of how and what we eat. If you look hard enough, you’ll find traces of dioxins in pretty much every place on earth. Paracelsus the famous medieval alchemist, used to put it straight and simple: it’s the dose that makes the poison.--Tim Parsons

Have a nice weekend!
And win some money betting horses...

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