JUNEAU (AP) The discovery of asbestos in rock at a city quarry has slowed work on construction projects.
Plans to repave a street near the Costco store and lay down gravel at some subdivisions and a trailhead on Glacier Highway halted last week because contractors were afraid of exposing their workers to tremolite, one of several minerals lumped together under the commercial name asbestos.
Exposure to asbestos can cause lung diseases such as asbestosis and mesothelioma. Several contractors say they will not touch rock from city-operated Stabler's Point Rock Quarry until new test results come back in a few weeks.
''The research I read about tremolite ... it's nasty stuff,'' said Larry Bingham, operations manager for Secon Construction. ''We can't risk our workers,'' he said.
The city and Secon Construction collaborated on tests at the quarry and Juneau's rock-crushing operations last week.
The Alaska Department of Transportation, which uses Stabler's Point rock for road projects, has shipped off mineral samples for analysis at the Colorado School of Mines.
So far, city engineers do not believe there is a public health risk from the tremolite-bearing rock and they have not found asbestos at other quarries.
Michelle Helmick-Murphy acquired about 190 tons of Stabler's Point rock to fill in her residential lot. She was planning to cover it with soil and plant a vegetable and flower garden.
''I'm going to wait for the test results before getting excited about it,'' she said.
Asbestos seems to be part of the local geology, said Rorie Watt, the city's chief capital-improvement project engineer.
Tremolite can contain one of the most dangerous forms of asbestos, but asbestos fibers are only dangerous when they are inhaled. It can take 15 to 40 years for asbestos-related diseases to show up in people's lungs, said John Wheeler, a toxicologist with the federal Agency for Toxic Substances and Disease Registry in Atlanta.
''What you really want to evaluate is air levels,'' Wheeler said.
City officials say they believe there is little risk to the public from Stabler's Point rock because contractors bury it or mix it with asphalt.
Watt said he does not plan to track all locations where Stabler's Point rock has been placed unless test results show a potential health hazard.
In California, scientific modeling has shown a public health risk from asbestos-related diseases because toxic dust from exposed rock along roads and construction projects invaded homes, schools and ball fields.
State and federal officials have spent millions paving over asbestos-tainted gravel roads and covering up asbestos-contaminated soil in a high school soccer field in El Dorado County, Calif.
Levels of naturally occurring asbestos in El Dorado County rock can be about 10 percent, Wheeler said. Initial tests at Stabler's Point showed two rock samples contained 3 percent and 5 percent tremolite asbestos.
The state and the municipality of Juneau do not have asbestos laws, Watt said. He intends to draft local rules for handling asbestos based on California regulations.
People who blast or crush rock at the quarry likely would face the greater risk of asbestos exposure, scientists said.
The quarry contains thin veins of the fibrous material. Workers have been blasting rock there for at least five years.
City and state transportation officials said they did not realize asbestos was there until a private contractor commissioned tests earlier this summer.
The city sent out a memo Friday telling quarry users and contractors that federal law requires them to wear respirators when working around asbestos.
Ongoing testing could confound the school district's construction schedule. The district will not tolerate any safety hazard to its students, said projects director Deb Morris.
Information from: Juneau Empire, http://www.juneauempire.com
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