The federal government has strengthened the national air quality standard for soot and fine particle pollution.

The new standard is 20 percent more stringent than the current standard, which was set in 1997. It will require communities to make sure fine particle pollution is limited to 12 micrograms per cubic meter annually (the current limit is 15).

Fine particle pollution, or soot, comes from power plants, refineries, diesel trucks and buses. EPA Administrator Lisa Jackson says the stricter rule will have a major effect on health.

“Science shows us that microscopic particles can penetrate deep into the lungs,” she said. “This can lead to a wide range of serious and costly health effects including heart attacks, strokes and aggravated asthma.”

Jackson estimates the strengthened standard could provide health benefits worth up to $9 billion by 2020. That’s $170 dollars for each dollar invested in implementing the standard, she says.

The only counties that are projected to not meet the new standard by 2020 are in California. Jefferson County isn’t currently meeting the new standard, but is close. Air Pollution Control District spokesman Tom Nord says so far in 2012, the county has only exceeded the new 12 microgram per cubic meter standard twice. A decade ago, particle levels were routinely in the 20s.

Nord says he anticipates the county will be in compliance with the new standard within several years.

“This is something we’ve been expecting for awhile from the EPA,” he said. “We are going to work with the local community, the business community, to make sure that we can meet this standard; we feel confident that we will.”

Nord says he doesn’t expect meeting the new standard to be a “particularly painful” process, but he wasn’t sure by how much upcoming power plant retirements and upgrades will reduce the soot in the community. Louisville’s Cane Run coal-fired power plant is scheduled to be retired and replaced with natural gas by 2016, and the Mill Creek power plant will be updated with new pollution controls. Also playing a role are new fuel standards for vehicles, which will also reduce the amount of soot pollution in the city’s air.

Local groups including the Sierra Club, Rubbertown Emergency ACTion, Kentucky Interfaith Power and Light and the Kentucky League of Women Voters applauded the new standard.