TRENTON, N.J. (AP) – New Jersey filed suit against the federal government Tuesday, leading a nine-state challenge of new rules it says fail to protect children and expectant mothers from dangers posed by power plants’ mercury emissions.

The suit, filed in the U.S. Court of Appeals for the District of Columbia Circuit, criticizes rules announced March 15 by the Environmental Protection Agency as failing to do all the Clean Air Act requires. The eight other states involved in the suit are California, Connecticut, Maine, Massachusetts, New Hampshire, New Mexico, New York and Vermont.

“Our ultimate goal is to persuade the court to invalidate the EPA’s rules dealing with mercury emissions,” Attorney General Peter C. Harvey said. “Our goal is to reduce mercury emissions that we know are harmful to pregnant women and children.”

The EPA-ordered reductions would cut mercury emissions from the nations 600 coal-burning power plants by nearly half within 15 years, from 48 tons of mercury pollution a year down to 24.3 tons in 2020. Opponents of the plan say that so-called cap-and-trade rules provide an out for the worst polluters by allowing them to trade “pollution credits” with cleaner plants.

“EPA’s emissions trading plan will allow some power plants to actually increase mercury emissions, creating hot spots of mercury deposition and threatening communities,” Harvey said. “It’s an anti-human health position. The EPA is putting private profit ahead of public health, and it’s a mistake.”

New Hampshire Attorney General Kelly Ayotte said states cannot wait for stricter national controls.

“EPA has ignored sound science, the Clean Air Act and New Hampshire’s recommendations on setting strict federal controls for mercury,” Ayotte said.

“We have no choice but to seek reversal of this misguided rule.”

An EPA spokesman did not immediately return a call seeking comment.

Mercury from smokestacks can wind up in waterways and ultimately be consumed by humans who eat tainted fish. The toxic metal causes nerve damage, which can be harmful to children and fetuses even at low levels of exposure.

The cap-and-trade rule sets a nationwide cap on allowable pollution, then allocates an amount to each state, which then set limits on each plant. Plants that exceed the limit can buy pollution credits from plants emitting less mercury pollution than they’re allowed.

Cap-and-trade starts in 2010. Until then, utilities don’t have to do anything specifically to control mercury. Instead, they must follow another regulation to reduce two other pollutants – which EPA says will also help control mercury.

The lawsuit challenges the deadline given to power plants for compliance, and assails the EPA for exempting power plants from having to install the strictest emissions control technology available. That technology would cut mercury pollution by 90 percent, according to the New Jersey Attorney General’s office.