Do Phthalates Mess Up Genital Development in Baby Boys?

Are environmentally ubiquitous chemicals called phthalates, which leach from certain types of plastics, making the penises of baby boys smaller or hampering their testicles from descending into the scrotum? That’s the concern raised by a new paper published this month in the journal Environmental Research.

The study, the latest in an ongoing salvo against the chemicals by University of Rochester researcher Shanna Swan, is an extension of preliminary results that she published in 2005. That earlier paper—and the newer one—make the case that prenatal exposure to low doses of phthalates muck with several aspects of human male genital development, including the distance between the anus and the genitals at birth. Swan’s critics have railed against her research, which has received loads of media attention over the years despite being what they call scare science. The new paper seems to be flying largely under the radar, except for the coverage of it in this USA Today article.

In May, I published an article about phthalates and a sidebar that explained how--if you’re so inclined--you can try to avoid these extraordinarily widespread chemicals.