Two new studies raise new concerns about phthalates -- specifically the one known as DEHP, or di(2-ethylhexyl) phthalate.
Phthalates are a class of chemicals used widely in a variety of products, from fragrances to No. 3 soft plastics (others: IV bags and tubing, beauty products, PVC toys, vinyl shower curtains, car seats, and wallpaper). The U.S. recently banned the use of several phthalates in children's products, because of evidence that early exposure affects the normal development of boys by reducing testosterone levels. Other research has linked exposure to certain phthalates to obesity and related health problems. While one recent study cast doubt on the theory that phthalates affect young boys, two new studies raise concerns.
One small German study, published in Pediatrics, linked DEHP to liver problems in premature babies, and pointed to plastic intravenous feeding tubes as the likely route of exposure.
A second study of lab rats published in Environmental Health Perspectives (pdf) examined the effect of a mixture of chemicals, including DEHP, all of which are known or suspected of being endocrine disrupting chemicals -- meaning they interfere with the normal action of hormones. In this case, each of the chemicals studied interferes with the action of male sex hormones (androgens). The study found that a combination of chemicals magnified the effect, so that the total response in rats was greater than the effect predicted by the sum of each chemical.
In addition to DEHP, the researchers tested a prostate cancer drug, finasteride, and two fungicides -- vinclozolin (found as a pesticide residue in highest concentrations on strawberries and frozen green beans) and prochloraz. "According to the study results, combined exposure on malformations of external sex organs was synergistic, and the observed responses were greater than would be predicted from the toxicities of the individual chemicals," according to a summary of the research by Beyond Pesticides. "In relation to other hallmarks of disrupted male sexual development, including changes in anogenital distance, retained nipples, and sex organ weights, the combined effects were dose additive. When the four chemicals were combined at doses equal to no-observed-adverse effect levels estimated for nipple retention, significant reductions in anogenital distance were observed in male offspring."
To avoid phthalates, avoid No. 3 plastics, and scrutinize the ingredients of products for "fragrances" or the acronyms DBP, DEP, DMP, DEHP, BxBP or DMP -- all of which signal the presence of phthalates.
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