"After six months of stalling, EPA not only failed to address the grave dangers posed to communities and children by its cap-and-trade program for mercury emissions, it made the program worse by further weakening standards," New Jersey Attorney General Zulima Farber said. The petition was filed in federal court in Washington.

Mercury from smokestacks can enter waterways and be consumed by humans who eat contaminated fish. The toxic metal can cause nerve damage and damage the heart, brain and kidneys, according to the EPA.

The states argue that the cap-and-trade system will endanger children near some power plants that pollute but use credits to do it legally.

The agency has defended its mercury rules in the past, saying they will reduce mercury emissions by 70 percent and they represent the nation's first attempt to control such emissions.

The other states included on the petition are: Wisconsin, California, Connecticut, Delaware, Illinois, Maine, Massachusetts, Michigan, Minnesota, New Hampshire, New Mexico, New York, Pennsylvania and Vermont.

-- Associated Press