SMO — Ultrafine particulates and black carbon levels in the neighborhood surrounding the Santa Monica Airport dropped significantly during a four-day period in 2010 when all airport activities were suspended for repaving, according to a new study by the South Coast Air Quality Management District.

The study was conducted over the course of approximately three weeks surrounding the airport’s full closure between Sept. 19 and Sept. 24, 2010 for repaving of the runway, which was mandated by the Federal Aviation Administration.

Scientists from the South Coast Air Quality Management District took the opportunity to conduct experiments to see what the difference in combustion-related pollution was when no planes were taking off from the airport.

Three monitoring stations were placed at different distances and downwind of SMO’s runway 21, which sees the majority of the takeoffs and landings.

Another two stations were put in the living room and back yard of Virginia Ernst, a longtime resident of the neighborhood whose home is 300 feet from the east end of the airport.

“They had the equipment going for several weeks,” Ernst said. “There was a cart about 3 feet by 2 feet, and it had equipment on top of that.”

A second piece of equipment, about the size of a microwave, was also placed in her home.

Scientists came between 6 a.m. and 6:30 a.m. every few days to check on the equipment and get readings on pollution, leaving before Ernst went to work in the morning.

“Anything to solve this problem,” she said.

The problem rests with jet fumes, which Ernst says have been getting worse in the past 19 years.

One jet blast blew Ernst’s lawn furniture across her patio — it was replaced by the owner of the plane — and another knocked down a neighbor’s fence.

“Douglas was a dream, compared to what they’ve got now,” Ernst said, referring to the aircraft developer that created the predecessor to the modern jet at SMO.

Monitors followed jets and turbo prop planes, but not piston planes.

The equipment Ernst hosted did find spikes in both ultrafine particle and black carbon emissions before and during take off of airplanes, although the readings inside the home were considerably lower than those taken at any of the outdoor sites.

When the airport shut down, the emissions levels reduced considerably.

According to the study, concentration of ultrafine particles at the East Tarmac site before and after the repaving project were about 12 to 17 times more elevated than the highest spike recorded when the airport was shut down.

The back yard site showed considerably less dramatic reductions, with levels before and after the shut down only reaching four to seven times as high as the highest reading when no planes were landing or taking off from the airport.

Larger planes tended to create more emissions, with highest emissions typically seen within the last two minutes of a holding period — when planes are waiting to take off — and during take off.

Although the study could quantify the peaks and troughs in ultrafine particles and black carbon, the substances are mostly unregulated by the federal government, and there aren’t many studies about their effects on human health.

Those effects aren’t a mystery to Janice Nolen.

“Well, they can kill people,” said Nolen, the assistant vice president for national policy and advocacy for the American Lung Association (ALA).

Ultrafines and black carbon have been associated with heart attack, stroke and worsening symptoms of asthma, Nolen said.

Most data the ALA uses comes from studies surrounding highways rather than airports, but health risks have been identified in an area 300 to 500 meters from major roadways.

SMO officials could not comment on the study, which is now in the hands of the airport’s consultant Dr. Paul Roberts, who conducted an air quality study on the Central Valley for the California State government.

“We’ve given the report to our experts. Once the analysis is done, we can comment,” said Airport Manager Robert Trimborn. “We’ve always been proactive in any kind of emissions study, which are done by the agencies that set the standards, and want to get that information out to the public.”

ashley@smdp.com