When you think of pollution, you might picture an industrial center like Camden, N.J., or Jersey City. But new research shows that when it comes to a potent class of cancer-causing toxic chemicals, many American parking lots are a lot worse.

New studies paint an increasingly alarming picture – particularly for young children – about how these chemicals are being spread across big swaths of American cities and suburbs by what may seem an unlikely source – a type of asphalt sealer. These sealants are derived from an industrial waste, coal tar.

Four new studies (links are at the end of this article) announced this week further implicate coal tar-based asphalt sealants as likely health risks.  The creosote-like material typically is sprayed onto parking lots and driveways in an effort to preserve the asphalt. It also gives the pavement a dark black coloring that many people find attractive.

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Coal tar is a byproduct of the steelmaking industry. In 1992, the U.S. Environmental Protection Agency declared that it would not be classified as a hazardous waste, even though it met the characteristics of one, because it could be recycled for uses that include coating asphalt. That meant steel mills didn’t have to pay for costly landfilling or incineration of the waste.

 

 

 

Only in recent years have scientists discovered the ill effects of this practice.

Coal tar sealants are used most heavily in the eastern United States, but were applied in all 50 states until Washington state banned the products last year. More than a dozen local governments, including Washington, D.C., and Austin, Texas, also have banned the coal tar sealants in favor of the other major type of sealant, which is asphalt-based.

Asphalt-based sealants contain about 1/1000^th the concentration of the cancer-causing chemicals that coal tar-based products do. Home Depot and Lowe’s stores have dropped the coal tar sealants from their product lines, but still some 85 million gallons of the coal tar-based sealants are applied annually in the United States.

The new research, published in peer-reviewed science journals, focuses on a class of chemicals found in coal tar and known as “polycyclic aromatic hydrocarbons,” or PAHs. Previously, researchers believed that people’s exposure to PAHs came primarily through food, which contains trace amounts produced primarily from smoking food or cooking it at high temperatures in practices such as grilling, roasting, and frying. PAHS are produced when any organic matter burns.

The new research shows:

• It appears that children – especially those from 3 to 5 years old – living by coal tar-sealed parking lots and driveways are getting a bigger dose of PAHs from house dust than from their food. The kids who put their hands in their mouth most often are likely receiving 9 ½ times more exposure through house dust than through food, according to research led by E. Spencer Williams, a Baylor University human health risk assessment expert. That’s just from the house dust. When the kids are outside in the yard or playing on coal tar-sealed pavement, they likely are picking up much larger doses.
• While researchers previously theorized that airborne PAHs come mostly from power plants, factories and cars’ and trucks’ tailpipe emissions, U.S. Geological Survey researchers measured large amounts vaporizing into the air off coal tar-sealed parking lots.  The concentrations coming off parking lots in suburban Austin, where the researchers are based, were higher than in centers of heavy industry, including Jersey City and Camden, N.J.; Chicago; London and Manchester, England; and Guangzhou, China. The Austin parking lots tested were three to eight years old. Much more off-gassing occurs in the first few years after the sealants are applied, researchers said.
• Concentrations measured four feet above the coal tar-sealed lots in some cases exceeded health-protection guidelines recommended by a European Union science panel to protect against cancer. The United States has no similar guidelines.
• Extrapolating from the 85 million gallons of coal tar sealants laid down annually and the out-gassing rates measured in Austin, Geological Survey researchers calculated that nationwide, more PAHs are getting into the air from coal tar-sealed parking lots, driveways and playgrounds than from all the auto and truck exhaust.

“That’s a lot,” said Barbara Mahler, a USGS scientist involved in the research.

Researchers previously had shown that coal tar-sealed parking lots were shedding tiny bits of the material, which was washed by rain into nearby waterways – killing, sickening and maiming aquatic creatures such as salamanders, minnows and, importantly, bugs at the base of the food chain. The chemicals kill tadpoles, cause tumors on fish, stunt growth of aquatic creatures and reduce the number of species able to live in a waterway.

As a result of being washed into waterways by stormwater, these chemicals’ concentrations have been rising over the last two decades, even as levels of most contaminants are headed down, Geological Survey researchers showed.

The chemicals are getting into the house dust, researchers think, when small bits are eroded off pavement and tracked into nearby homes.

Scientists also had previously demonstrated that toxic constituents of coal tar were showing up in the dust of homes adjacent to parking lots and driveways, raising questions about health effects on children in those homes, especially toddlers who frequently put their hands in their mouths. Coal tar is known to cause cancer in humans, as well as genetic mutations in lab animals.

One of the new studies helps quantify that risk. Kids who are average in terms of how often they put their hands into their mouths are getting 2 ½ times as many PAHs from house dust as from food, while those in the 95^th percentile of hand-to-mouth behavior – they do it more than 94 percent of other kids – get 9 ½ times as much from the dust.

Researchers still would like to know how much of a toxic dose those same kids are getting when they play outside in yards next to coal tar-sealed asphalt, or on the asphalt itself. The level of cancer-causing chemicals in the dust on the asphalt itself has been measured at about 37 times the levels found in house dust.

“Those concentrations are a good bit higher and this study doesn’t include that at all,” said Williams, the Baylor researcher. “That may be important because just one little fingerful could be a relevant dose,” meaning one that worries health experts.

While researchers have known about contamination of water and dust, the findings about air pollution are new. Significant amounts of PAHs continue to vaporize off coal tar-sealed lots even years after the sealant is put down.

“When we look at a seal-coated parking lots, in any direction we look we see these really strongly elevated concentrations,” said Peter Van Metre, a U.S. Geological Survey scientist based in Austin. Of the dust on the coal tar-sealed pavement, he said: “It would just take a tiny amount of that to be a large enough dose for it to be significant.”

Companies that sell and use the coal tar sealants have previously disputed the growing body of evidence of the coal tar sealants’ danger being amassed by scientists from the Geological Survey, the University of New Hampshire, Baylor and other institutions.

Repeated attempts this week to reach an industry representative, Anne LeHuray, executive director of the Pavement Coatings Technology Council, for comment on the new studies were unsuccessful. In an email on Thursday, LeHuray said she was tied up at a meeting of the pavement council in Memphis.

Generally, the pavement council has attacked previous coal tar research on technical grounds.

Read previous articles on coal tar sealants:

Study sees parking lot dust as a cancer risk

State bans coal tar sealants in big win for foes

The pavement council has fought bans – sometimes successfully – when they have been proposed by local and state governments. In addition to the local governments that have forbidden use of the coal tar sealants, some governments have placed restrictions on their use, including the state of Minnesota and the California Department of Transportation. Restrictions also are in effect in more than 40 Illinois municipalities.

U.S. Rep. Lloyd Doggett, a Democratic congressman from the Austin area, has previously filed legislation calling for a nationwide ban on coal tar sealants. He plans to refile the legislation, a Doggett spokeswoman said, but is currently embroiled in a redistricting fight.

Tom Ennis, an Austin city official who helped get coal tar sealants banned there, has now launched a campaign to support a nationwide ban.

“You’re looking at a big urban air quality” problem, Ennis said. “It’s completely unacceptable and something needs to be done.”

The studies announced this week appeared in the science journals Environmental Science and Technology, Chemosphere, Atmospheric Environment,  and  Environmental Pollution.

InvestigateWest is a non-profit journalism center based in Seattle. If you value this kind of in-depth, independent news reporting, please consider making a tax-deductible donation to support further work of this kind.

By Myron Levin, FairWarning.org

Wind power is riding a strong breeze. In the last five years, generating capacity in the U.S. has nearly quadrupled. Clusters of tubular wind towers, rising up to 300 feet above ridgelines and gusty plains, are an increasingly familiar sight.

But in the scramble to expand clean energy and green jobs, the wind industry has fallen short on worker safety.

Thousands of the giant wind machines violate a federal requirement to give technicians who work inside the towers enough maneuvering space to get up and down their ladders safely. The standard says the space near the ladder should be free of permanent obstructions that could cause serious head or back injuries if a climber slips or is moving fast.

There are about 36,000 of the wind towers in the U.S., and more are being added all the time. Most are produced overseas to meet international codes. For reasons they won’t explain, the manufacturers either ignored the U.S. standard, or thought it wouldn’t apply to them.

The companies "evidently didn’t look into U.S. codes and standards, especially safety standards, in doing their designs," said Patrick Bell, a senior safety engineer with the California Division of Occupational Safety and Health, or Cal-OSHA, and a member of a federal OSHA wind energy task force.

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OSHA officials say they’re not aware of any serious injuries so far. Still, the violations are so widespread that they have flummoxed safety regulators, who are trying to figure out the extent of the hazard and what to do about it.

"We could conceivably issue citations," said Bell of Cal-OSHA, "but we might end up taking all of our compliance officers off other industries to run from one wind farm to the next."

"We are trying to work with the industry," he said, "because it’s a huge industry with all the wind towers going up."

The manufacturers have been reluctant to talk about the problem. Officials with Vestas Americas, part of Vestas Wind Systems A/S of Denmark, the world’s biggest turbine supplier, declined to be interviewed and would not respond to written questions. GE Energy, the top U.S. wind turbine maker, took the same stance. Both companies referred inquiries to the American Wind Energy Assn., a trade group.

Michele M. Mihelic, the association’s manager of labor, health and safety policy, said in an email to FairWarning that the group "cannot make a blanket statement that all wind turbines comply or not."

"Each wind turbine make and model is different," she said.

The OSHA standard dates to the 1970s, and applies to the use of fixed ladders at work sites generally, not to wind towers specifically. It requires a clearance of 30 inches from the ladder so workers can safely move up and down. If there are permanent obstructions within the climbing space, they must be shielded so workers can squeeze past without getting hurt.

The main issue with tower designs is the use of heavy steel bolts and rims known as flanges to join their long, tubular sections. In the two or three spots where the sections are fastened, the bolts and flanges intrude at least several inches into the safety space.

Two field technicians have sought to draw attention to the issue, saying they were stunned by the prevalence of the problem.

"Between my friends and I … we’ve been in thousands of wind turbines and haven’t found one that’s compliant with this issue," said Ed Oliver, 47, of Dana Point, Calif.

"We can’t believe this exists everywhere we go," said Nick Nichols, 45, of Zephyr Cove, Nev. "The regulations are there for a reason."

The men said they have seen nothing worse than bruised tailbones and minor scrapes from encounters with the flanges. But they said it’s only a matter of time before there are serious injuries. They pointed to the growing use of "climb assists" that use motors and pulleys to support part of the weight of technicians, allowing them to climb faster and basically rappel downward in the descent.

Oliver and Nichols have complained to OSHA. They also took the unusual step of offering the industry their own version of a safety device, called a deflector. The website for their company, Pinnacle Wind USA, shows what looks like a short section of a playground slide covering a flange. "Developed BY tower climbers, FOR tower climbers," it says.

Their efforts haven’t brought any love from the wind industry. In August, they were stunned by an email to Nichols from Mihelic of the wind association.

"You should…be aware that there are people posing as OSHA compliance officers and/or OSHA consultants and are threatening people in the industry with citations if they don’t buy your product," the email said.

Mihelic added that OSHA had been told about the scheme and "has requested that if any of our members are approached in this manner to please report it to them so they can investigate."

The two men immediately suspected it was a bogus claim designed to discredit them. Soon after, Nichols enlisted the help of U.S. Sen. Dean Heller, R-Nev., to see what OSHA knew about it.

David Michaels, assistant secretary of labor for Occupational Safety and Health, responded Oct. 11 with a letter to Heller that seemed to contradict Mihelic. OSHA officials were unaware of "any reported cases of OSHA impersonators threatening companies to purchase Pinnacle Wind USA products," the letter said.

Mihelic told FairWarning she stood by her email to Nichols.

Meanwhile, the ladder issue remains up in the air.

OSHA has not yet issued citations for violations of the standard. Brian Sturtecky, OSHA’s area director in Jacksonville, Fla., and chairman of its wind energy task force, said the agency is preparing a "letter of interpretation" to clarify how the standard will be applied

The result could be a mandate for the industry to retrofit thousands of towers. Or, the industry could get a pass if the agency decides the hazard can be controlled by other measures, such as training.

The task force is examining other safety issues in the industry in the wake of some serious accidents.

In August, 2007, a worker was killed and another injured in the collapse of a tower at a wind farm near Wasco, Ore. Also, OSHA fined Outland Energy Services $378,000 for safety violations after an employee suffered serious electrical burns at an Illinois wind farm in October, 2010.

FairWarning is a nonprofit, online investigative news organization focused on public health and safety issues.

By Myron Levin, FairWarning.org

Federal health officials are calling for protective measures at job sites where workers may be exposed to erionite, a cancer-causing mineral similar to asbestos that is found in rock and soil in at least a dozen western states.

An advisory published Tuesdayby the National Institute for Occupational Safety and Health recommended a series of steps to prevent employee exposure to eronite fibers at sites such as gravel quarries and road projects. The NIOSH alert noted that erionite was responsible for "remarkably high" rates of mesothelioma, a lethal form of cancer that devastated several Turkish villages where erionite was concentrated in rock and soil.

Erionite fibers pose an inhalation hazard similar to asbestos, but available research suggests erionite is more dangerous.

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As reported in October by FairWarning and msnbc.com, authorities have long known that erionite is widespread in the West but haven’t investigated the potential risks, apparently believing there was little chance of human exposure.

As a result, amid an expansion of roads, pipelines, and power lines in remote areas, erionite remains unregulated, and federal agencies until now have failed to alert land-use officials, developers and residents so they might take precautions.

About 30 officials and scientists from federal health and environmental agencies last month held a day-long erionite workshop in North Carolina. "At a minimum, we can begin to start to educate the public and policymakers," said Dr. Aubrey Miller, a senior medical advisor at the National Institute of Environmental Health Sciences, who chaired the meeting. "I certainly don’t want to count bodies later."

The steps recommended Tuesday by NIOSH, though purely voluntary, are a first attempt to address potential occupational risks.

"From the evidence at hand …it’s prudent and it’s reasonable to approach controlling exposures as one would control asbestos,"said NIOSH spokesman Fred Blosser.

Erionite, a member of the zeolite family of minerals, is formed from volcanic ash that has been weathered by water. Like asbestos, it is harmless until it is disturbed, and the microscopic, needle-like fibers waft into the air.

Until the late 1970s, when the mesothelioma epidemic was first reported in Turkey, asbestos was thought to be the only cause of the rare cancer. But erionite was found to be the culprit. In the hardest-hit villages, where 40 percent to 50 percent of all deaths were caused by mesothelioma, erionite was abundant in soil and rock, and was used to build homes.

Animal studies showed erionite to be 100 to 800 times more carcinogenic than asbestos and, according to a scientific paper, "almost certainly the most toxic naturally occurring fibrous mineral known."

The NIOSH alert acknowledged the paucity of data on erionite risks in the U.S. According to co-authors David Weissman, director of the agency’s division of respiratory disease studies, and Max Kiefer, director the NIOSH’s western states office, "little is known about exposures currently experienced by U.S. workers." But it said there is some evidence of health effects among road construction workers exposed to erionite-containing gravel or soil.

It cited studies in North Dakota. In 2005, it was revealed that erionite-laden gravel mined in the western part of the state had been used to cover hundreds of miles of unpaved roads.

Mesothelioma develops decades after initial exposure, and no proof has emerged of high rates of the disease in North Dakota. However, air sampling along the gravel roadways and in vehicles, including inside school buses, revealed erionite level similar to those in some stricken Turkish villages. And a preliminary health study found that two road maintenance workers had mild lung scarring consistent with breathing mineral fibers.

In the absence of clear risk data and regulations, however, use of erionite-containing gravel has continued in the state. The North Dakota Department of Transportation has banned its use in state road projects, but some local governments and private companies rely on it still.

Complicating the picture, the state is in the midst of one of the greatest oil booms in U.S. history, with a huge spike in truck traffic tearing up unpaved roads and increasing the need for maintenance. To use only erionite-free gravel to patch the roads would mean hauling from 40 miles away, which is “cost prohibitive,” Reinhard Hauck,  the auditor and treasurer of Dunn County, N.D., told FairWarning. Local officials are "behind the 8 ball constantly trying to figure out how to maintain the infrastructure we have."

Scott Radig, director of waste management for the state Department of Health, said the agency has provided advice to energy companies and construction contractors on controlling dust and avoiding gravel with erionite content. But Radig said such steps are purely voluntary, and he doesn’t know how many companies comply.

The NIOSH advisory listed more than a dozen measures to control potential hazards, including employee training and determining if erionite-containing material is present before beginning work.

Other steps included wetting soil and rock to reduce dust; using respirators and other protective equipment; showering and changing clothes before leaving work; and ensuring work clothes and boots are left at work to prevent hazardous fibers from being brought home. 

FairWarning is a nonprofit, online investigative news organization focused on public health and safety issues.

By Myron Levin, FairWarning.org

Mesothelioma, an exceedingly rare and lethal form of cancer, was once thought to be caused only by inhaling asbestos fibers.

Then in the late 1970s, when astonishing rates of the disease were reported among villagers in central Turkey, studies determined that a different fibrous mineral was the culprit. Erionite was abundant in native soil and stone, and so easy to work with that villagers had used it to build homes.

In the most devastated communities, known locally as “cancer villages,” mesothelioma rates were off the charts--responsible for 40 percent to 50 percent of all deaths. Animal studies showed erionite to be 100 to 800 times more carcinogenic than asbestos and, according to a scientific paper, “almost certainly the most toxic naturally occurring fibrous mineral known.”

In the U.S., medical journals and news stories presented the Turkish epidemic as a gruesome, but distant, catastrophe. They largely omitted a key fact: Erionite deposits are present scores of sites in at least a dozen western U.S. states.

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Interviews and documents from the 1980s show there was a flicker of interest in assessing the risks in the U.S., but researchers and officials lost interest and moved on to other things.

The result is that, after three decades, erionite remains a word most Americans—and many environmental officials--have never heard. Amid an expansion of roads, pipelines, power lines, wind and solar farms and recreation sites in remote areas of the West, erionite is unregulated, and federal agencies have failed to alert land-use officials, developers and residents of affected areas so that they might take precautions on their own.

Uneasy about the long silence, some government officials and scientists  are trying to fashion a federal response. Toward that end, a meeting planned next week at the National Institutes of Health, will bring together representatives of the Environmental Protection Agency, the National Institute for Occupational Safety and Health, the Mine Safety and Health Administration, and the U.S. Geological Survey, to discuss potential risks from erionite and other hazardous minerals.

“We need to be cautious because there’s clear evidence of disease” from mineral fibers, said Dr. Aubrey Miller, a senior medical advisor at the National Institute of Environmental Health Sciences who will chair the meeting.

“At a minimum, we can begin to start to educate the public and policymakers,” he told FairWarning. “I certainly don’t want to count bodies later.”

Driving the renewed interest is fear of repeating past government failures to promptly inform the public of potential hazards.

One case involved Libby, Montana, where asbestos contamination from a mine near the town was blamed for scores of deaths and illnesses among workers and residents. Vermiculite ore tainted by asbestos and mined from about 1920 to 1990 was given to unwary residents for use as insulation and in other building projects. When the EPA arrived on the scene in 1999, it came under scathing criticism for failing to act earlier to inform the community and launch a cleanup.

Another was the disclosure that road crews in North Dakota, heedless of the danger, had used erionite-tainted gravel to cover hundreds of miles of unpaved roads in the western part of the state, including school bus routes, along with parking lots and recreation sites.

Erionite is found where volcanic ash and rock have been weathered by alkaline water, Like asbestos, it is harmless until it is disturbed, and the microscopic, needle-like fibers become airborne. And like asbestos, greater and more frequent exposure generally means higher risk.

No proof has emerged of erionite-related illnesses in North Dakota or other western states, but experts say that is less than reassuring. Mesothelioma usually takes 30 to 50 years to develop, is sometimes mistaken for other cancers, and when identified often is automatically assumed to be asbestos-related.

In Mexico, a mesothelioma cluster has been reported in a rural area near the border of Zacatecas and Jalisco states. Medical reports say victims had no known exposure to asbestos, but lived on a plain rich in zeolites, the mineral family that includes erionite.

When Turkish researchers in the 1970s found soaring rates of mesothelioma in the Cappadocia region, they linked it to villagers inhaling dust while farming potatoes and scallions. They soon discovered that residents were also being exposed inside their homes built with erionite-containing stones.

Research later uncovered a genetic factor. People in the hardest-hit villages had long been shunned by horrified outsiders, leading to inbreeding and magnifying the risk for those with a genetic predisposition to the harmful effects.

Documents reflect a brief interest in the health implications for the American West.

In an area of north central Nevada where erionite was present in road dust, researchers from the University of Utah examined chest radiographs from a local hospital, but turned up nothing unusual. But they also published a case report describing a local road construction worker with respiratory disease whose lung biopsy showed fibrous particles “consistent with erionite” An investigation of mesothelioma “in the Intermountain region and exposure relationships would be useful,” they wrote.

But according to two of the researchers, Dr. William Rom, currently director of the pulmonary division at the New York University School of Medicine, and Dr. Kenneth Casey, now at the University of Cincinnati College of Medicine, their request for a grant from the Institutes of Health was turned down.

About the same time, with the Defense Department proposing to build a network of “racetracks” to shuttle nuclear MX missiles over a vast area of the Great Basin, opponents seized on the problem of erionite dust. The plan was abandoned, and interest in erionite faded, too.

It was revived by chance after an official from the U.S. Geological Survey gave a talk at the spring banquet of the University of North Dakota geology department in 2005. He spoke of the need for geologists to be aware of naturally occurring hazards, mentioning erionite. An assistant professor named Nels Forsman piped up: “Hey, we’ve got some of that right here in North Dakota.”

In the mid-1980s, Forsman, had done a field study in the Killdeer Mountains of western North Dakota for the state geological survey. His 1986 report noted the presence of erionite, but he knew nothing of the events in Turkey and didn’t give it much thought.

“Nobody in our department had heard anything about it” until the banquet, Forsman told FairWarning.

But Forsman then alerted the geological survey, which contacted the state health department, which in turn brought in the EPA. Their investigation launched in 2006 revealed that erionite-containing gravel from pits in western North Dakota had been spread over some 300 miles of unpaved roads.

Air sampling along the gravel roadways and in vehicles, including inside school buses, revealed erionite levels similar to those in some stricken Turkish villages, though at lower concentrations than the most devastated communities. A preliminary health study that included 15 people thought to have high exposure to road gravel found two with pleural plaques, or lung scarring, consistent with inhalation of mineral fibers.

Though the erionite situation quickly erupted into a major story in North Dakota, it drew virtually no media attention outside the state. So complete was the blackout that last December, when Dr. Michele Carbone, a prominent mesothelioma researcher, briefed lung specialists at a national medical meeting in Chicago, it was the first they had heard of it, according to some who attended.

In response to the discovery, the North Dakota Department of Transportation has banned the use of erionite-containing gravel on state roads. But the western part of the state is in the midst of a gigantic oil boom, bringing a massive increase in truck traffic and road dust that residents say clouds visibility and may be harming crops and human health. Last month the state industrial commission and two of the most affected counties authorized a study of the best ways to reduce road dust.

Some agencies in other states are taking safety measures, though the efforts have been isolated and piecemeal.

In eastern Oregon, which has large erionite beds, the state transportation department is conducting a study. The idea is to avoid being “blissfully ignorant” of the locations of erionite or other naturally occurring hazards in future construction and maintenance work, said Matthew Mabey, a research engineer with the Oregon Department of Transportation.

In Montana, where road building crews in the 1960s ripped the top off an erionite-bearing mountain and spread the fill along more than three miles of state highway 323, soil samples have shown erionite levels as high as 20 percent.   Highway workers have been directed to use protective suits and respirators when their work involves land disturbance, such as clearing ditches and mowing vegetation.

Erionite also occurs in rocky outcrops in parts of the Custer National Forest in southeastern Montana and western South Dakota. Forest Service officials have adopted dust control measures, including wetting down helicopter landing spots when fighting wild fires.

In a joint report, Custer National Forest and Montana officials cited the need for a federal policy to reduce risks from erionite and naturally occurring asbestos.

Mining is another activity without any rules on erionite exposure. No erionite has been mined in the U.S. for about 30 years, but it is sometimes mixed in with other types of zeolites that are produced at a few mines in the West. According to an EPA report in1987, a producer contacted by the agency stated that its zeolite products “can contain 10 to 30 percent erionite.”

Most zeolites produced today are of two varieties, chabazite and clinoptilolite. With their ability to trap and filter contaminants, they have been used to purify water and to treat radioactive and other hazardous wastes.

From its Mud Hills mine in the Mojave Desert in California, Steelhead Specialty Minerals has produced clinoptilolite for cleanup of the tsunami-stricken Fukushima nuclear plant in Japan, said its president Wallace McGregor.

Along with others in the industry, McGregor said current operators are well aware of erionite, and take pains to avoid it. But “I wouldn’t say there isn’t a trace,” he added. It’s “maybe an overstatement that there are not traces of a little bit of this, and a little bit of that, in a zeolite deposit.”

Carbone, who will be among those presenting at the meeting at the Institutes of Health, has called for action to prevent and detect mesothelioma cases in North Dakota and other erionite-rich areas.

Mesothelioma is “a cancer that in most cases can be prevented,” he said in an interview. “We really have the possibility to do something…to prevent cancer in future generations.”

FairWarning is a nonprofit, online investigative news organization focused on public health and safety issues.