Results of a national study released Thursday show that plastic baby bottles, including some popular brands, leach dangerous levels of a toxic chemical into the fluids they contain. The chemical, a synthetic hormone known as bisphenol-A, is linked to the development in laboratory animals of breast and prostate cancer, obesity, diabetes and other disorders.

Health and environmental groups in Maine said the study underscores the need to monitor the chemicals used in products for infants and children and urged support for a bill that would put Maine at the forefront of promoting safer consumer products.

Bisphenol-A is used in the manufacturing of many hard plastic products. In addition to baby bottles sold by major manufacturers such as Gerber, Playtex and Evenflo, the chemical is used in making some hard plastic Nalgene water bottles popular with hikers and other outdoors enthusiasts, some sippy cups for toddlers, some dental sealants and the linings of many food and beverage cans, including all infant formulas, according to information provided by the Alliance for a Clean and Healthy Maine.

The group, which released a report on the study Thursday, includes the Environmental Health Strategy Center, the Learning Disabilities Association of Maine, the Natural Resources Council of Maine, the Maine Council of Churches and other advocacy organizations.

Researchers at the University of Missouri tested 10 new polycarbonate baby bottles purchased at popular retail outlets such as Target, CVS, Wal-Mart and Toys “R” Us. The bottles were purchased at stores in eight states, including Maine, and Washington, D.C.

The bottles were filled with water and let stand for 24 hours. The water then was tested for the presence of bisphenol-A, first at room temperature and then after the bottles were heated to 80 degrees Celsius to simulate repeated washings. At room temperature, the chemical was not detected in the water. After heating, the water contained bisphenol-A at levels the researchers deemed “a potential health risk for infants.”

Dr. Brown’s brand bottles leached the most bisphenol-A, while Avent brand bottles leached the least.

The report notes that the bottles in the study were brand-new and that repeated washings would further degrade the plastic and hasten the release of bisphenol-A.

Telephone calls seeking comment from Gerber, Playtex, Dr. Brown’s and Avent were not immediately returned Thursday. A spokeswoman for Evenflo released an e-mail statement saying the company “has no comment due to pending legislation.”

The study recommends parents look for baby bottles made of glass or polypropylene plastic, which is often stamped with a “5” on the bottom and does not contain bisphenol-A. One manufacturer is BornFree.

The release of the study report fueled support Thursday for a legislative proposal sponsored by House Majority Leader Hannah Pingree, D-North Haven. LD 2048 would require manufacturers of children’s products that contain “chemicals of high concern” to disclose the presence of those substances to the Maine Department of Environmental Protection. It would authorize the DEP to require manufacturers to substitute safer alternatives, when available, and to participate in an interstate clearinghouse for product safety information.

In a prepared statement, Mike Belliveau, executive director of the Environmental Health Strategy Center, said, “Maine lawmakers have a golden opportunity to help fix our broken chemical safety system. Passing this bill sends a common-sense message to manufacturers: Tell us what dangerous chemicals are in your products and offer safer alternatives to protect children’s health.”

A public hearing on LD 2048 has not yet been scheduled. A spokeswoman from the DEP said Commissioner David Littell “strongly supports the concepts and goals of the legislation but remains concerned about the fiscal impact.” Gov. John Baldacci is expected to submit “safer chemical” legislation that is “complementary” to Pingree’s bill, according the spokeswoman.

To read the full report, visit www.babystoxicbottle.com. For more on bisphenol-A in consumer products, visit the National Geographic “Green Guide” site at www.thegreenguide.com/doc/114/bpa.