In its most critical response yet, the U.S. Environmental Protection Agency has denounced as “seriously flawed” and deceptive a mining industry critique of the federal agency’s El Dorado Hills asbestos testing.

The National Stone, Sand & Gravel Association’s review of the 2004 air tests on Community Park playgrounds and nearby schoolyards largely contradicted the agency’s findings of naturally occurring asbestos.

The EPA found none of the criticisms valid, according to its 17-page response released this week.

Overall, the industry’s evaluation runs afoul of “widely accepted scientific standards” for sampling and measuring asbestos in the environment, the agency report said. The point-by-point rebuttal also spotlights 10 instances where the industry consultant, R.J. Lee Group Inc. of Pittsburgh, omitted or mischaracterized key details when it said that its air tests “showed no significant exposure” to asbestos. “The R.J. Lee Group’s report misleads the public and muddles the message to the community,” said Daniel Meer, the EPA’s emergency response chief in San Francisco.

Rich Lee, president of R.J. Lee Group, called Meer’s remarks “unfortunate.” He stood by his critique: “We used only generally accepted scientific procedures in our analysis and review.”

At issue is a decades-old standoff between public health scientists and the mining industry over the definition of “asbestos,” a category of fibrous minerals.

At stake for the mining industry are regulatory constraints on a bedrock industry, figuratively and literally, which supplies sand and gravel for the building and highway industries. For the EPA and other public health agencies, the misidentification of asbestos carries life-or-death consequences. Development in rapidly growing El Dorado Hills and other foothill communities has churned up asbestos in the native rock and soil, releasing the breathable fibers into the air.

Fibers that get lodged in the lungs can lead to fatal respiratory disease years later.

The dispute centers on the identity of particles the EPA collected in October 2004 in air and soil sampling at Community Park and on playgrounds at Silva Valley Elementary, Jackson Elementary and Rolling Hills Middle School. Technicians wearing air monitors simulated dust-raising games such as baseball. The EPA’s findings, released last May, were striking: Every activity “significantly elevated” individual exposure to a form of asbestos called amphibole.

Most disease experts regard amphibole asbestos as many times more toxic in causing mesothelioma – a deadly cancer of the chest lining – than the more common chrysotile asbestos owners of older homes might see wrapped around pipes for insulation.

The mining lobby commissioned its $81,000 review on behalf of the El Dorado County superintendent of schools, Vicki Barber, who has touted the report to dozens of officials.

Barber stops short of endorsing the mining report. But the critique fuels doubts she and many other local officials harbor over the reliability of EPA tests. On the EPA’s latest response, Barber said, “We are very pleased the dialogue is continuing and we are hopeful the questions we have asked will be addressed.”

Following in the unenviable footsteps of El Dorado Hills, asbestos concerns have swept into the city of Folsom like a dry wind carried down Highway 50. Due to heightened levels of naturally occurring asbestos in the Empire Ranch area, the public is being given until Tuesday to comment on the Department of Toxic Substances Control’s mitigation plan for the Empire Ranch Elementary School site.DTSC site investigations between April 2004 and July 2005 discovered asbestos clusters at both the site of the new high school and the elementary school site, and further tests revealed heightened asbestos levels in several parts of the Empire Ranch subdivision site being developed by Elliott Homes.

Whether the contamination is more widespread isn’t known, according to DTSC officials.DTSC school unit chief Mark Malinowski said the tests were restricted to the proposed school boundaries themselves. Using these results to predict what may exist in surrounding areas is misguided, he explained, because even the levels found at the adjacent elementary and high school sites differed significantly from each other.”The asbestos fibers are so dependent on geology,” Malinowski said. “It is difficult to make assumptions about what’s in the surrounding areas.”

Given that, a September 2004 board letter from the Sacramento Metro Air Quality Management District implied the problem may be in other parts of the city as well. “I anticipate that much of the city of Folsom, though not all, may be included as part of the jurisdictional area for ATCM (airborne toxics control measure) requirements, and I shared this with the city,” air pollution control officer Larry Greene said in the letter.

Terry Trent, a former El Dorado County resident and asbestos activist, also fears the problem may be larger than Empire Ranch.”The mesothelioma cluster in Folsom is troublesome, due to several variables,” he said in an email. “One is that Folsom residents have been exposed much longer than El Dorado (County) residents and the community was historically small, dense and somewhat isolated.”The question that’s on everyone’s mind, of course, is just how dangerous is this stuff.

“That’s the 64 million dollar question,” said Melanie Marty, the state Office of Environmental Health Hazard Assessment chief of air toxicology and epidemiology branch. If that were known, “we would have a much better handling on the issue than we do.”

“We do know that environmental exposure can cause cancer,” she added. “We don’t know the levels.” Given that, Marty said most regulatory agencies don’t employ a threshold when it comes to policing asbestos. In that vein, Malinowski said the DTSC developed conservative health safety criteria, saying the department was “very aggressive about requesting actions.”

So aggressive, in fact, that it has received criticism in the past for requiring school districts to do costly mitigations that some say could pay for books or extracurricular programs. Mitigation costs at Vista Del Lago are costing the district around $1.5 million, while costs at the elementary school site hover around $1.2 million.

“We’re really striving to be both safety conscious and also have a balance,” said Malinowski.

To combat what was found at the school site, the cleanup plan proposes to place geotextile fabrics in playfields and landscapes; cover the fabric with 8 to 12 inches of clean soil; place erosion control blankets over sloped areas; and develop and operations and management plan for further control. The geotextile fabric resembles a tightly woven cloth and is used to suppress dust.

Meanwhile, asbestos remains a troubling area of study in which much is feared and little is known. State and federal funding for asbestos study have only begun to pick up again. There are different strains and different levels of toxicity, but Marty said that doesn’t mean that some forms are not dangerous, “which is how some people interpret it.”

Asbestos use remains widespread in the building industry, and Marty said more forms are being found in California, primarily in the foothills. Soil-based asbestos is responsible for heightened mesothelioma risks, but both Marty and Malinowski said there is no qualitative understanding of what levels of exposure lead to disease.