Last week, the Environmental Protection Agency put new limits on the amount of soot that industrial plants can pump into the air.

The agency was meeting a deadline set by a federal court that ruled existing limits on fine airborne particles were not strict enough. The new standard limits the soot particles to 12 micrograms per cubic meter - down from 15 micrograms - and is the first tightening of these standards since 1997.

These fine particles, 2.5 micrometers in diameter, about one-seventh the width of a human hair, can penetrate deep into lungs and even into bloodstreams. Health studies show they contribute to heart and lung diseases, asthma and early deaths.

Communities that fail to meet the new standard by 2020 face penalties that could include the loss of federal transportation funds.

New Jersey plants already meet the new soot limits, but the rule will still be good for state residents because it will force our neighbors to clean up the emissions they send our way.

The state Department of Environmental Protection figures that about one-third of the air pollution in New Jersey comes from states to our west. This imported pollution is the reason New Jersey does not meet federal standards for clean air.

Only federal regulation can make a dent in that kind of pollution.

And the EPA, headed by former state DEP commissioner Lisa Jackson, has been pushing for tighter air pollution regulations while New Jersey officials have sent mixed messages about the state's commitment to battling out-of-state polluters.

In 2011, Gov. Chris Christie sued to try to shut down the Homer City Station, a western Pennsylvania power plant that ranks as one of the biggest polluters in the country. But at the same time, he declined to join with other states in a lawsuit to support the EPA's Cross-State Air Pollution rules, which sought to limit sulfur dioxide and nitrogen oxide pollution across state lines.

Fortunately, Jackson's EPA has been busy while New Jersey dithered.

A year ago, the agency issued regulations limiting the amount of mercury, arsenic and other deadly pollutants produced by the oldest and dirtiest coal plants in the country. The regulations had been delayed for 20 years, and they finally addressed the largest remaining source of uncontrolled pollution in the country.

Then, as now, some business groups attacked the regulations, saying they were too costly and would hurt local economies.

Our answer is the same now as it was then: Any area that seeks a competitive advantage by sacrificing the health of its residents is practicing a false economy.