It’s been a bad month for chemicals and masculinity. Last week 80beats covered the discomforting link found between the chemical bisphenol A (BPA), which is found in any number of consumer products, and erectile dysfunction. Now the villains are phthalates, chemicals used to make plastics softer and more flexible. A new study in the International Journal of Andrology has raised a storm of concern that prenatal exposure to these chemicals could make boys less masculine in their play preferences.
Phthalates, which block the activity of male hormones such as androgens, could be altering masculine brain development, according to Shanna H. Swan, a professor of obstetrics and gynecology at the University of Rochester Medical Center and lead author of the new report [Los Angeles Times]. To test whether that link extended into behavior, Swan’s team tested women for phthalate levels midway through their pregnancy and then checked back in on the children four to seven years later.
The researchers asked parents to report their children’s patterns of play, but they knew they also had to separate any potential phthalate effect from the “nuture ” side of question. To determine how parental views might sway behavior, parents completed a survey that included questions such as, “What would you do if you had a boy who preferred toys that girls usually play with?” They were asked to respond with whether they would support or discourage such behavior, and how strongly [TIME].
To truly assess the risks posed by a ubiquitous group of chemicals found in everything from vinyl shower curtains to bug spray, researchers need to study their cumulative impact on human health, declares a 
