Monitors at Los Alamos National Laboratory have detected no radiological or chemical contamination in the air since the start of the Las Conchas Fire on Sunday, a lab official said Tuesday.

"We've detected no releases, and we wouldn't expect to. The fire has not burned in any areas of concern," said Fred de Sousa, spokesman for the lab's environmental programs.

Air quality is a worry among nearby residents and environmental activists as the Las Conchas Fire continues to burn near the town of Los Alamos and a national lab that has played a decades-long role in the U.S. nuclear bomb-making program. On Tuesday, the fire was burning to the south and west of the lab, and, at some points, only a road separated the fire from lab property, said Los Alamos County Fire Chief Doug Tucker.

Except for a small blaze quickly extinguished Monday at one of the technical areas, the fire has not burned on lab property where trace amounts of nuclear and chemical contaminants remain, including the lab's nine landfills, eight of which await remediation, de Sousa said. In addition, soil in some canyon bottoms around the lab contain trace amounts of nuclear materials such as plutonium, tritium and uranium due to runoff from work done on ridges above during the lab's early decades, the lab spokesman said.

"Contaminants that were acceptable at the time are present at the bottom of the canyons," de Sousa said. He listed some of the areas in question as Los Alamos Canyon, Pueblo Canyon, DP Canyon and Cañon de Valle.

"Each canyon is a separate case," de Sousa explained, adding that not every canyon contains traces of every element.

The concern among activists and nearby residents is that a blaze in those areas would throw nuclear and chemical particulates into the air.

That concern led U.S. Sen. Tom Udall to call on the U.S. Environmental Protection Agency to conduct extra air-quality testing.

"I have requested that the EPA do additional monitoring — not because I question anything that LANL is doing," Udall said during a Tuesday news conference in Los Alamos about the Las Conchas Fire.

Already, extra air-quality monitors are on their way to the area from the nation's Environmental Protection Agency and the U.S. Forest Service, a state official said Tuesday.

"EPA had eight of them in Las Vegas, N.M., three hours ago," Tom Skibitski said around 4 p.m. Tuesday. Skibitski heads up a state Environment Department bureau that oversees the lab. "We expect we will take six monitors and send them to downwind communities."

Monitors also are likely to be installed in Santa Fe, Española and Taos to measure the air quality as the Las Conchas Fire burns, Skibitski said.

The extra monitors — about 70 of them — will supplement the lab's air-quality testing, measuring the atmosphere for everything from metal particulates to radioactive materials, de Sousa said. Results from 60 or so of those monitors are tested every two weeks, while data from 11 monitors is produced every 15 minutes "near real-time," de Sousa said. In addition, the lab has deployed four high-volume monitors, used only in special circumstances, which "suck in many more times air than our other monitors."

"They are very sensitive," de Sousa said.

In addition, the EPA said Tuesday night that it will fly a specialized aircraft, the ASPECT plane, designed to collect air quality data. The flights will start Wednesday morning and will continue through Saturday.

Meanwhile, five monitors posted around the lab's perimeter by the state test continuously for isotopes of plutonium, uranium and americium, and for metals ranging from "arsenic to zinc," Skibitski said.

A sixth state-owned monitor — mobile and solar-powered — will be deployed soon after a location is determined, Skibitski said.

Data from the state's monitors haven't been analyzed since the start of Sunday's blaze. "We just swapped out the filters today," Skibitski said, adding that a commercial laboratory contracted by the state will analyze the particulates captured in the filters.

Since the fire started, communication between state and federal officials has been nearly continuous, Skibitski said.

The state bureau chief spent most of Tuesday sitting with officials from the EPA at LANL's Emergency Operations Center in Santa Fe.

"The communication is very good," he said.

Contact Trip Jennings at 986-3050 or tjennings@sfnewmexican.com.