Closer look at factors needed to measure risk of asbestos at sites, experts say

Whether asbestos found in soil poses a threat to humans depends on a variety of factors, including what type of asbestos it is and how much was found, according to experts and government officials.

Asbestos, which prosecutors say has been found in soil at two sites in Islip Town, is a mineral fiber used in construction and linked to lung cancer. Asbestos is hazardous only when tiny fibers of it are inhaled into the lungs, said Chuck Nace, an environmental toxicologist with the U.S. Environmental Protection Agency.

“In the soil itself, it’s not a big issue,” said Nace, who spoke generally and not specifically on the ongoing asbestos dumping investigation in Islip Town. “Where you have a bigger issue is when . . . you get asbestos fibers that can get released into the air. That’s where the problem is.”

Where asbestos is in the soil is also a factor, Nace said.

“If it’s lying on the surface of the ground, anything that disturbs the ground — wind, people walking on it, running, driving on it — those are all forces that could take those fibers and give them energy and put them into the air,” he said.

Earlier this month, Suffolk County District Attorney Thomas Spota said investigators had found asbestos at Brentwood’s Roberto Clemente Park and a privately owned site in Central Islip. In addition, Spota’s office is investigating whether multiple sites in the Town of Islip may have been used to dump illegal fill.

The town has said that air quality tests from the area around the park show no evidence of asbestos fibers in the air.

The type of asbestos at the park and any other location is important in determining the level of hazard to humans.

Even pulverized construction debris containing asbestos might not be an issue if the asbestos is tightly bound to other materials in floor tiles or shingles and hasn’t broken off into tiny fibers, said Dr. Brooke Mossman, professor of pathology at the University of Vermont School of Medicine.

“There are only certain fibers and certain sizes that you can breathe,” Mossman said. “Chunks in floor tiles are frequently bound to resins, and when they come out, they don’t come out in fibers.”

In addition, the type of asbestos commonly used in construction in the United States — chrysotile — is not as dangerous to human health as the amphibole asbestos once used in shipbuilding during World War II, or in insulation in the United States before it was banned in the 1960s, she said.

“Since the 1990s, we’ve learned that the amphiboles are definitely much more pathogenic and much more able to cause disease at lower levels than chrysotile,” Mossman said. “They are more durable in the lung.”

The amount of asbestos in the soil also is a factor, Mossman said, with higher amounts posing more of a threat than lower concentrations.

Even if asbestos fibers are breathed in, it doesn’t necessarily lead to mesothelioma or lung cancer — two cancers associated with the mineral that can take decades to develop. Typically, disease is seen at high exposures of high amounts of asbestos, and shorter exposures mean disease is less likely, according to Nace.

“The human body has some really good defensive mechanisms where they can clear things out of the lung,” Nace said. “You have white blood cells that will attack the fiber” and expel it from the body.

A typical probe includes investigators in protective gear performing activities that would normally be done on the contaminated site while monitors on their bodies collected air samples, he said.

“We’d be able to see whether the activities they’re doing are releasing fibers at a concentration that we feel would cause adverse health effects,” Nace said.

Asbestos in soil is often addressed either by capping it in place — placing a layer of fabric over the area, then covering it with clean soil — or removing the contaminated soil to a regulated landfill, Nace said.

Removing the soil, however, requires a slew of protective measures to ensure particles don’t become airborne, which is why capping is often a better solution for soil found within communities, he said. –JENNIFER BARRIOS, http://www.newsday.com/news/health/closer-look-at-factors-needed-to-measure-risk-of-asbestos-at-sites-experts-say-1.8209927?firstfree=yes