A third of the most popular children's toys in the United States this year contain harmful chemicals including lead, cadmium, arsenic and mercury, a US consumer group found on Wednesday.
The Ecology Center, which published its findings on the website HealthyStuff.org, tested nearly 700 toys ahead of the Christmas shopping season and found that 32 percent contained one or more toxic chemical.
The number of products exceeding current federal limits for lead in toys has dropped by 67 percent since 2007, though the chemical, which can affect the nervous system, was still present in 18 percent of toys, according to the center.
Lead levels in toys varied, with seven percent containing more than 40 parts per million (ppm), the highest level recommended by the American Academy of Pediatrics in 2007.
Another three percent of the products tested had levels exceeding 300 ppm, the federally-mandated limit, the study said.
Among the toys with detectable lead levels were the Barbie Bike Flair Accessory Kit, the Dora the Explorer Activity Tote and the Kid's Poncho sold by Wal-Mart stores, the Michigan-based Ecology Center said.
The study, which used a portable x-ray fluorescence analyzer, also found cadmium levels greater than 100 ppm in 3.3 percent - or 22 - of the products tested and arsenic levels over 100 ppm in 1.3 percent - or nine - of the toys.
The authors said they were also concerned after finding that 42 percent of the toys tested contained PVC.
"PVC is the worst plastic from an environmental health perspective because it creates major hazards in its manufacture, product life and disposal, and can contain additives that are dangerous to human health," the study said.
The center, which has tested some 4,000 children's products over the past three years, has created an online database where consumers can check whether the toys they have purchased contain toxic chemicals.