OFFICIALS: EPA RULES TOO LAX LOCAL CONCERN OVER MINE DUST.

Byline: Kerry Cavanaugh Staff Writer

Southern California air regulators have warned that proposed national standards for soot don't go far enough to protect public health and could limit the region's ability to regulate dust from mining operations.

The U.S. Environmental Protection Agency has proposed new standards to cut the level of particulate matter - microscopic particles and droplets in the air.

As planned, the new particulate matter standards are stiffer than current pollution limits, but they're more relaxed than what the EPA's own scientific advisory council recommended.

That troubles the AQMD and other health organizations, that point to research that links low levels of particulate matter to decreased lung function in children and an increased risk of cardiovascular disease.

``We feel the proposed standards don't adequately protect public health within the margin of safety recommended,'' said Jean Ospital, health effects officer with the South Coast Air Quality Management District.

The AQMD is preparing a letter to the EPA outlining the agency's concerns.

Local air officials also are concerned that the EPA proposal would exempt mining and agriculture from regulations for coarse particulate matter, or PM10, which includes particles smaller than 10 microns in diameter that are formed from dirt, tire dust and gases.

That's a big concern in Santa Clarita, where residents and the city are fighting a 56.1 million-ton gravel mine planned in Soledad Canyon near Agua Dulce.

The potential increase in particulate matter is one of the main reasons Santa Clarita is opposed to the mining project as proposed, said Gail Ortiz, a city spokeswoman.

``Our studies have shown the air quality will be severely impacted, and anything that will limit the South Coast Air Quality Management District's ability to regulate mining is something we would be extremely concerned about,'' Ortiz said.

U.S. Environmental Protection Agency spokesman John Millet said the agency exempted mining and agriculture from being regulated under coarse particulate matter standards because there is no evidence that windblown dirt and dust kicked up in earth-moving activities is unhealthful.

``We determined that they don't pose a risk. People have dealt with windblown dust for a long time,'' Millet said.

But Ospital with the AQMD pointed to studies in the Coachella Valley, where the particulate matter is largely windblown dirt, that have shown an increased rate of hospital visits and death when coarse particulate matter levels are higher.

The EPA proposal would cut the level of daily fine particulate matter to 35 micrograms per cubic meter from 65 micrograms. The annual standard would stay the same. Fine particulate matter is smaller than 2.5 microns and can get trapped deep in the lungs and move into the blood stream.

For comparison, a human hair is about 70 microns.

The federal agency would limit coarser particles, or those between 2.5 and 10 microns at 70 micrograms per cubic meter per day.

The EPA is taking comments on its proposal until April 17. For information, visit www.epa.gov/air/particlepollution/actions.html.

Kerry Cavanaugh, [phone]

kerry.cavanaugh(at)dailynews.com