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April 10, 2007
Some real science on "new car smell"
One of the most persistent urban legends about phthalates claims that they are a component of “new car smell,” and that they pose a risk to drivers and passengers. This legend gained some recent impetus when an organization called the Ecology Center ran some tests on car interiors. It tested the components of windshield deposits, and also tested materials in car interiors, and said it found phthalates in both.
But it never tested the air! Fortunately, however, other organizations have directly tested the interior air in autos. A report by Australia's well-respected Commonwealth Scientific and Industrial Research Organization (CSIRO) discussed the "new car smell" with which we are all familiar, and suggested that the sources of the odors might present some risks to health. The CSIRO report named nine different substances found in the new-car interior air that could be a problem in high concentrations. Phthalates were not on the list.
In 2007 a team of scientists from the Technical University in Munich, Germany, checked the contents of the air in one new and one three-year-old old auto “parked in sunshine.” Using halogen lamps, the researchers brought the interior air up to 139 degrees Fahrenheit, then tested for organic compounds in the air. It found dozens. Phthalates were not among them. One other reason phthalates are not likely to contribute to new car smell: they have little to no odor.
Posted by Marian at 8:42 PM | Comments (0)
April 5, 2007
Fish story?
We were both curious and disturbed last Fall when the U.S. Geological Survey released a report on smallmouth bass in West Virginia rivers showing intersex characteristics, because the report mentioned that two phthalates (DEP and DEHP) were found in the blood of the fish. They were just two of the many chemicals detected, and no claim was made that any of the chemicals were causing the sex changes. But the implication just hung there.
So we asked one of the members of our Environmental Research Toxicology Group to review the report. What immediately jumped out, he reports, is the following sentence: “Diethyl hexyl phthalate [DEHP], a known endocrine disruptor…” What? No reference was offered to support the statement. “Indeed,” wrote our toxicologist, “there is no such valid reference.” That is, in laboratory tests on rodents, no phthalate has shown the ability to mimic or to block the action of a hormone. We see this urban legend repeated often in the media and on pressure-group Web sites, but not in government reports.
A second problem also emerged—the very distinct possibility that laboratory contamination explained the presence and detection of DEHP, rather than it coming from an environmental source. In fact, the report conceded that the detection of DEP may have come from reagent contamination. If that is true, it is also likely true for DEHP, which is commonly found in laboratory equipment. But the water wasn’t tested for the presence of any phthalates at all, so no data were presented to test that possibility one way or the other. Without testing the water, it’s impossible to know how low phthalate levels may have been, and it’s even possible that the fish were swimming in DEHP-free, DEP-free water.
In short, the report cannot be read to show or suggest that phthalates caused the changes in the fish – or in fact whether there were any phthalates in the fish blood at all!
Posted by Marian at 4:16 PM | Comments (0)
April 2, 2007
Phthalates make you fat?
Over the years, almost everything has been blamed for making Americans fat, from television watching to dieting to having overweight friends and family to drinking diet soda. And of course, just plain being an American has been linked to obesity. And recently, a merry-go-round of man-made chemicals has been blamed in various media outlets for making us fat. Some researchers at a recent scientific meeting in early 2007 blamed chemicals for the rise in obesity, and now a researcher at the University of Rochester has added phthaltes to the list.
But this report is the thinnest of reeds. It shows a statistical correlation between phthalate exposure and waistline but offers no causal connection. It applies to men but not women. And the study isn’t based on girth (body mass index) – but on belt size.
Scientific research may ultimately show that certain things inhibit the body’s ability to lose weight or make it easier to gain weight – like lack of sleep. And we welcome quality research, properly validated, as advancing scientific knowledge. What does the American Obesity Association say about the causes of obesity? It says there are three factors: genetics; failure to consume nutritious foods in reasonable portions and to get regular physical activity; and failure to adapt healthy weight control habits. And The Centers for Disease Control probably best sums up the state of scientific knowledge: “Rising rates of obesity seem to be a consequence of modern life, with access to large amounts of palatable, high calorie food and limited need for physical activity.”
Toi get another viewppoint, see Michael Fumento's article at http://www.spectator.org/dsp_article.asp?art_id=11205.
Posted by Marian at 11:10 AM | Comments (0)