Chemicals known as phthalates, used as a softening agent in a variety of widely used vinyl-based plastics, have been shown to mimic prenatal estrogen, and may cause stunted genital development in boys.
Phthalates (THAY-lates), some forms of which were recently banned for use in European products, is used to make polyvinyl chloride (PVC) more pliable. The chemicals are so common in plastic products that they are nearly unavoidable.
They can be found in cosmetic products like nail polish, nail polish remover, hair products, skin lotion, deodorants and perfumes; soft vinyl teethers, toys, raincoats, and vinyl miniblinds, miniblind dust, wallpaper and flooring; IV tubing and other medical devices used for ill infants/children, plastic wrap, adhesives, makers, and some oral medications. Phthalates can found in anything containing vinyl, and are even responsible for that “new car smell.”
While normal exposure is considered to be safe enough for adults, high exposure to some phthalates can cause cancer. And after years of prenatal testing on animals, the first test has been done on humans-with startling results. Baby boys whose mothers had high exposure phthalates showed smaller penis volume, stymied testicular descent, and a decrease in anogenital distance (the distance between the anus and the base of the penis, AGD).
Shanna Swan, of the University of Rochester School of Medicine and Dentistry in New York, conducted the study of 85 baby boys. Swan’s team measured the level of phthalate metabolites in the urine of pregnant women and found that four were linked with shorter ADGs on their sons. All the boys had genitals classified as normal, but 21% of them had below average ADGs. Typically, a shorter ADG translates to a smaller penis.
When tested on animals, babies with high exposure to phthalates exhibited a lack of “masculine” behavior associated with testosterone like “rough-and-tumble” play and lesser aggressiveness.
Phthalates are becoming an increasing concern of environmentalists and continues to lose friends. But manufacturers maintain that the chemicals are thoroughly tested and deemed to be safe. The FDA deemed them safe in 1984 and hasn’t reviewed them since then.
Critics of Swan’s study say that a larger sample and more urine tests of each subject need to be included in replicated studies for the results to hold more power.
The results of the study will appear in Environmental Health Perspectives.
A list of products containing phthalates can be found here.
