Certain vinyl baby bibs sold at Toys "R" Us stores appear to be contaminated with lead, laboratory tests have shown, making the inexpensive bibs another example of a made-in-China product that may be a health hazard to children.

The vinyl bibs, which feature illustrations of baseball bats and soccer balls and Disney's Winnie the Pooh characters, are sold for less than $5 each under store brand labels, including Especially for Baby and Koala Baby.

Tests this summer, financed by the Center for Environmental Health of Oakland, Calif., found lead as high as three times the level allowed in paint in several styles of the bibs purchased from both Toys "R" Us and Babies "R" Us stores in California.

A separate test by a laboratory hired by The New York Times of the same Toys "R" Us bibs, purchased in Maryland, found a similar level of contamination.

"These bibs are exposing children to lead in an unnecessary way," said Caroline Cox, research director at the Center for Environmental Health, a nonprofit agency that for the last decade has been testing consumer products for lead, in an effort to remove them from the market.

The study, which included more than 1,000 families with infants or toddlers, was published Tuesday in the Journal of Pediatrics.

"The most important fact to come from this study is, there is no clear evidence of a benefit coming from baby DVDs and videos, and there is some suggestion of harm," lead author Frederick Zimmerman, an associate professor of health services at the University of Washington and Seattle Children's Hospital Research Institute, said in a prepared statement. "The bottom line is, the more a child watches baby DVDs and videos, the bigger the effect. The amount of viewing does matter."

"The results surprised us, but they make sense," added study co-author Andrew Meltzoff, co-director of the University of Washington's Institute for Learning and Brain Sciences, in a prepared statement.

"There are only a fixed number of hours that young babies are awake and alert. If the 'alert time' is spent in front of DVDs and TV instead of with people speaking in 'parentese' -- that melodic speech we use with little ones -- the babies are not getting the same linguistic experience," Meltzoff said.