Seems we can't get rid of phthalates fast enough. Yet another study suggests that the chemicals, which are found in many plastic toys, household items and personal-care products, may be detrimental to children.

The U.S. Environmental Protection Agency last year added phthalates to its list of "chemicals of concern" targeted for possible future regulation. California law prevents any product made for young children that contains more than one-tenth of 1 percent of phthalates from being made or sold in the state.

In a study published in the journal Environmental Health Perspectives, researchers measured phthalates in the urine of 319 pregnant women, then followed the children born to these women until age 3. The study found that children whose mothers had the highest levels of phthalates had increased rates of behavior problems and decreased skills related to voluntary movement compared to children whose mothers had the lowest levels. Girls whose mothers had the highest levels were also found to have decreased mental development at age 3 compared with girls whose mothers had the lowest phthalate concentrations.

It's unclear why phthalates may be harmful to children. One theory is that the chemicals interfere with thyroid function, which is known to have a significant effect on all aspects of fetal, infant and child development.