Chemicals called phthalates commonly used in vinyl and other plastic products may interfere with the normal development of baby boys' genitalia, University of Rochester scientists concluded from new research.
The chemicals are also found in some perfumes, soaps, makeup, paints, and pill coatings, according to a report in Friday's San Francisco Chronicle.
Twenty-one percent of sons whose mothers' urine contained significant levels of phthalates had complications, including incomplete testicular descent and a smaller penis, versus 8 percent of other boys, the newspaper said.
The European Union has banned the chemicals and the California legislature is debating a measure, opposed by the chemical industry, to do the same, the newspaper said.
The researchers, noting that their study involved a relatively small sample of 134 babies aged 3 months to 24 months, recommended more research involving a larger pool of participants.
The study is published in the journal Environmental Health Perspectives.