Newest Articles:  Health troubles for 9/11 rescue workers Page 2

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CIG-BANNING DR. BLOOMY FANS THE FUMES OF HYPOCRISY

September 8, 2006
Steve Dunleavy

MAYOR Bloomberg is too smart a man to miss the irony he brought on his shoulders this week.

Let's go back to Dec. 30, 2002, when Bloomberg said of the bar-smoking ban, "We will save literally tens of thousands of lives."

He was talking about secondhand smoke in bars and restaurants and said we would all be healthier, if not wealthier, after the city curtailed it.

So smoking became the first legal product sold in New York that was partly banned in the city, based on Bloomberg's medical expertise, or access to pristine statistics about the effects of secondhand smoke in bars.

Some bars have lost from 10 to 30 percent of their business from Bloomberg's genius as a medical doctor - not to mention places that have gone out of business and lost the city tax money.

In fact, there has been absolutely no scientific, completely scientific study that links secondhand smoke to cancer. The city has never come up with one credible statistic.

But there has been a complete scientific study - from Mount Sinai research that shows that at least 70 percent of the thousands who labored at Ground Zero as first responders reported, and proved, that they had awful trouble breathing or worse.

Some are dead.

Bloomberg thinks these highly respected doctors are so crazy that they're barbecuing with the leprechauns.

"I don't believe that you can say specifically a particular problem came from this particular effect. There is no way to tell for sure and you've got to be very careful . . . If I say, 'I've got something because of this,' that's not just the way it works," said Dr. Bloomberg.

So now I have it perfectly clear: You ban smoking in bars with no statistics on secondhand smoke, but you are telling Mount Sinai, one of the best facilities in the world, they don't know their ear from their elbow when it comes to poison attacking the lungs like a spear.

Mayor Bloomberg, stick to politics and being a genius businessman, but you are as much of a medical expert as Dr. Kildare.
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MEDIA TORMENT
GETTING IT WRONG ON GROUND ZERO HEALTH

September 8, 2006
MICHAEL FUMENTO

STARTING in early 2002, firefighters who responded to the World Trade Center on that awful day the previous September began reporting what became labeled "World Trade Center Cough." Since then, numerous other first responders, later responders involved in search and clean-up and people who simply lived in the general WTC area have also reported a variety of respiratory and other ills.

Clearly, these people are suffering. But the question is: Are they suffering from a variety of toxins or alleged toxins that filled the air after the fiery explosions, or is their problem stress-caused psychogenic illness with perhaps some non-psychogenic illness mixed in?

Some scientific papers have indicated stress is a major factor. But the media have always favored the multiple toxin or "environmental illness" theory, and now insist as a chorus that a new report from the Mount Sinai School of Medicine in the journal Environmental Health Perspectives has settled it.

Certainly the study's authors don't equivocate: "Many who worked at Ground Zero in the early days after the attacks have sustained serious and lasting health problems as a direct result of their exposure to the environment there," Dennis Charney, Mount Sinai's dean for academic and scientific affairs, said in a statement issued with the study.

The media then dressed up these findings. For example, The New York Times claimed pneumonia among responders was "significantly more common the report actually says responders were merely more likely to have "sought medical help" for the illness. It had no data on actual diagnoses.

What the report did find, and which sounds awfully persuasive, is that 69 percent of some 9,500 responders said they suffered new or worsened breathing problems at the time of their WTC work. Further, in 59 percent symptoms persisted until their examinations (conducted from 2002 to 2004).

But these are just self-reported claims. The best indication these people have real symptoms is that, among non-smoking responders, twice as many had abnormal readings on spirometer (a device that accurately measures your ability to breathe) when compared to the general population.

Case closed? Not by a long shot.

One glaring problem is that those evaluated in the Mount Sinai study aren't a representative sample of responders, but merely an assessment of fewer than 10,000 from a total of about 40,000.

That is, this is not an epidemiological study. "An epidemiological study would want a group of people who are selected using a sampling design, where the group represents a study population," observes John Fairbank, co-director of the UCLA-Duke University Medical Center National Center for Child Traumatic Stress. "This doesn't."

This study looked only at the minority of responders who came to Mount Sinai to have their health monitored. People who "self-select" to participate in such medical studies tend to do so because they believe they're sick. So you can't make any meaningful comparisons to responders who didn't volunteer for the study or to the general public. This problem alone wholly invalidates the significance Mount Sinai and the media gave the report.

But what about those spirometer readings that were compared to those of the general population? All this device (invented 150 years ago) can do is measure, in various ways, breathing capacity. And labored breathing is a main symptom of psychogenic illness.

That is, a spirometer and its operator have no way of distinguishing labored breathing from psychogenic illness or non-psychogenic illness. There are devices that are much more valuable for this and they're commonly found in major hospitals such as Mount Sinai - but the Mount Sinai researchers didn't use them.

Ultimately, nothing in the Mount Sinai paper offers the least shred of evidence that the suffering responders aren't by and large suffering from psychogenic illness. Commonly misinterpreted as meaning "it's all in your heads," this actually means the symptoms can be quite real and debilitating but that they originated with stress. And 9/11 is synonymous with stress for the entire nation, and certainly far more so for the responders.

All stress disorders are unique, but the WTC illnesses do follow certain patterns. Denver psychologist Herman Staudenmayer, a critic of "environmental illness," points out one: "Typically with mass-psychogenic illness nothing happens initially and if you don't have an immediate affect you shouldn't have a long-term effect."

Indeed, in this case it took several months before responders began to complain. Now some say they were afflicted at the time; but they didn't then. As such, it's a direct parallel to Gulf War Syndrome, in which no complaints were registered until long after the war ended.

Another pattern is that suggestions that people are suffering environmental illness can wreak havoc on huge numbers of people.

In the Serbian province of Kosovo in 1990, for example, at least 4,000 residents suffered a mystery illness that included headache, dizziness, hyperventilation, weakness, burning sensations, cramps, chest pain and nausea. It began at a single high school and rapidly spread to dozens of schools in the province. Observed researchers: "An outbreak of respiratory infection within a single class appears to have triggered fears that Serbs may have dispensed poison." They hadn't.

Rumors of Israeli-spread poison gas caused a similar mass outbreak of illness among West Bank Palestinians in 1983.

That brings us to perhaps the most distressing aspect of the WTC outbreak.

In addition to the trauma experienced at the WTC site, the best explanation for these ills is that they have been induced by the media and select scientists who steadily beat the drum insisting responders ought to be sick. The bastion of these scientists since 2002 has been - surprise! - Mount Sinai.

A co-author of this study, Dr. Philip Landrigan at Mount Sinai, is the probably the nation's leading proponent of environmental illness. Another co-author, Jeanne Stellman, has been an influential (and heavily criticized) advocacy researcher on Agent Orange and dioxin since 1986.

Mount Sinai and the sycophantic media are no friends of those brave men and women who rushed to the World Trade Center on 9/11 or helped in the cleanup; they are their tormenters.

Our heroes deserve our compassion and help for their WTC-related illnesses, whether psychogenic or not. But true compassion begins with informing them there is no scientific evidence indicating they should be sicker than anyone else.
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Ground Zero ma: Mike heartless

August 17, 2006
MICHAEL SAUL

The mother of deceased Ground Zero worker James Zadroga described Mayor Bloomberg as a "cold, heartless person" for opposing a series of new laws that address the health battles of 9/11 rescuers.

"I don't think he realizes how the common people live - maybe for one month he should try and live on $500 a week," Linda Zadroga wrote in a letter to the Daily News.

"But when [you're] a billionaire, you have no concept of the so-called middle class. Well, one day he may have some tragedy in his family he will need to deal with, and then maybe he'll realize."

Zadroga was specifically angered by the mayor's pledge to donate $125 million of his personal fortune for a campaign to stop smoking worldwide, saying the billionaire should use that money instead to aid the 9/11 workers who helped the city.

"It is unrealistic that he could stop the world from smoking," wrote Zadroga, a smoker. "He gave so much money to other charities - why not accept [that] these people got sick from 9/11 and help [the] 9/11 fund?"

Her son NYPD Detective James Zadroga, 34, died in January of brain and respiratory complications, leaving behind his 4-year-old daughter, Tylerann.

On Monday, Gov. Pataki signed three bills aimed at covering the health costs of 9/11 responders - thousands of whom are suffering from debilitating illnesses as a result of their heroic actions nearly five years ago.

Bloomberg has voiced strong opposition to the legislation, saying he agrees with the intent of the laws but doesn't believe it's fair for Albany to impose costs on the city.

Asked to respond to Zadroga's letter, Stu Loeser, the mayor's press secretary, said, "While the mayor believes that this bill was flawed, that in no way discounts the respect he has for Detective Zadroga's heroic service to this city, or the sympathy the mayor feels to the Zadroga family for their loss."

The bills signed by the governor will ensure that Tylerann will receive 100% of her father's last salary as a pension benefit until she is 19. But Linda Zadroga told The News yesterday, "It's not about the money."

Zadroga said she wants Bloomberg to afford her son and all the other 9/11 workers the recognition they deserve.

"He's such a pompous ass, so cold-hearted," she said.

Mom's anguish

Here are excerpts from the e-mail Linda Zadroga, mother of 9/11 hero cop James Zadroga, sent to the Daily News:

"I read the article today about [Mayor] Bloomberg giving [$125 million] for the world to stop smoking."

"Well I don't think it could be done. He's still complaining about the bills passed for 9/11 victims; well maybe he should come down to reality and for one month live on $500 a week like my son did for four years.... "

"He lives in a mansion and after he leaves as mayor he would still be able to live in a mansion. He doesn't know the sacrifices the 9/11 workers suffered...."

"Well all I can say is Bloomberg is a cold, heartless person...."

"[My granddaughter] is 4 years old and has lost both her parents in a matter of three years, but Bloomberg doesn't seem to think about that in his perfect world."
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Health troubles persist for 9/11 rescue workers

6/25/2006
Stephanie Armour

It was late in the night when James Zadroga, sleeping beside his 4-year-old daughter, woke up to fetch her some milk. It was no easy errand: The former New York City police detective's lungs were so scarred that he needed supplemental oxygen to breathe.

In 2001, after the attack on the World Trade Center, he'd donned a paper mask and toiled at Ground Zero on rescue and recovery missions. Then he developed a cough and damaged lungs. Four years later, the 34-year-old was dying.

Sometime in that January night, Zadroga fell to the bedroom floor. At dawn, his father came into the room and found him, then gently woke the girl to tell her that Zadroga was dead. Her bottle was still in his hand. "I told her that her daddy has passed and she cried, 'No, no, he's just sleeping, he just got up to get me a bottle,' " says Joseph Zadroga, of Little Egg Harbor Township, N.J., who is now raising his granddaughter, Tyler Ann. Her mother died two years earlier.

An autopsy done by a New Jersey coroner attributed James' death to dust from Ground Zero. He had never been a smoker and had no previous respiratory problems. "No one should have to go through this," his father says.

Nearly five years after the terrorist attack, thousands of workers who toiled at the World Trade Center site continue to experience health problems, according to doctors at Mount Sinai Center for Occupational & Environmental Medicine in New York.

Zadroga's death — the first death linked by an autopsy to toxins at the site — has galvanized u nion leaders and politicians such as Sen. Hillary Rodham Clinton, D-N.Y., to call for more aid and investigation.

Concern over ongoing ailments plaguing World Trade Center workers is also leading to accusations that federal safety oversight at Ground Zero was lax — a charge that federal officials vigorously deny. Environmental Protection Agency (EPA) officials said in a statement issued to USA TODAY in May that they responded immediately as events unfolded, with the highest priority being to protect the environment and health of the people of New York.

The agency took more than 10,000 samples of air, water and dust, which yielded more than a quarter of a million results, and worked with other federal agencies to caution that workers should wear protective gear. Officials acknowledge that some workers from the site now are ill.

A class-action lawsuit has been filed alleging that the agency made false reassurances about the air quality at the site. No trial date has been set.

"The EPA said there was no danger, but this was the perfect storm of environmental toxins, and now we're paying the price," says Thomas Cahill, an air pollution expert and professor emeritus at the University of California, Davis, who studied the air quality around Ground Zero. "It was wildly toxic, and the EPA knew that. Hopefully, this will lead to a renewed effort not to forget these people."

About 40,000 workers toiled at Ground Zero, including immigrant day laborers, contractors, volunteers from other towns, paramedics, firefighters and police officers. They carried out myriad tasks, from digging through rubble in search of survivors to delivering ice and water. It's uncertain how many may now be sick.

A medical screening and monitoring program coordinated by Mount Sinai Center for Occupational & Environmental Medicine in New York indicates that more than half need immediate medical or mental health treatment. The estimate is based on a sample of the 16,000 workers screened to date. In fact, demand is so great that the waiting list for care through an independent treatment program offered by Mount Sinai is 16 weeks. The study looks at those who worked at the site during or shortly after the disaster.

Rare lung diseases emerge

One concern now is the emergence in first responders of rare lung-scarring diseases that could be fatal, says Robin Herbert, director of the World Trade Center program at Mount Sinai. Another concern is the potential for an increased rate of cancer in coming years. Asthma, chronic sinusitis and mental health problems also are common among those who were first on the scene.

"It's tragic. Our work has identified large numbers of heavily exposed workers who were never provided with appropriate respiratory protection," Herbert says. "A more vigorous public health approach might have prevented illnesses we're seeing today."

Glenn Greene, a Department of Justice lawyer representing former EPA administrator Christine Whitman, declined to comment on allegations that safety precautions were lax, as did the DOJ's press office. "From the moment the planes hit the World Trade Center, the men and women of the (EPA) ... began to do everything in their power to protect the people of New York," Whitman said in a February statement.

The city of New York, which has also been criticized for its handling of safety issues, said in a 2002 release from the law department that it "did everything in its power to assist people" and that "decisions were made with the best possible information available."

Vinny Forras just doesn't want his sacrifices to be forgotten. He believes more funding for treatment of first responders, as well as some sort of memorial for those who die after 9/11 of diseases related to exposure, is vital.

Forras, 48, was a volunteer firefighter at the South Salem (N.Y.) Fire Department who was dispatched to the World Trade Center the day of the attack. The first thing he saw was the firetruck that his best friend had been riding in smashed by the debris from the collapsing towers; his friend had been killed. Forras worked at the site night and day.

On his second day, he woke up at a triage center gasping for air; he was given steroids by the medical staff, he said, and sent back to work. At one point, Forras was working on rescue and recovery when he tried to climb down a beam; instead, he found himself buried briefly under the rubble. For an hour and a half, he says, he remained trapped underground.

Three months later, his breathing problems began, he says. Forras, who has never smoked, used to be able to run two or three miles a day. Now, he can get winded walking from the car to his home, he says.

He uses steroids and inhalers to breathe, antidepressants to help combat post traumatic stress disorder and sleep medications. He lives on disability payments from workers' compensation and Social Security. "It's very hard to see your own kids taking care of you," says Forras, founder of the Gear Up Foundation, a non-profit that donates fire equipment, prevention and training around the world. "We humbly did what we did. It was our job. But in 10, 15 years, we'll be ghosts. We're the Ground Zero walking wounded."

And that has become a growing fear: that some first responders at the scene could develop lung diseases and other ailments that will kill them — adding to the attack's death total. Many responders, such as volunteers from other cities, may not realize their health problems are related or get the assistance they need.

One million tons of dust

An estimated 1 million tons of dust rained down on the city and the 16-acre disaster zone, showering the area with asbestos, Freon, carcinogens, concrete, glass fibers, lead and other hazards. Workers inhaled caustic fine cement dust and a mixture of sulfuric acid, a byproduct of combustion, which defeated the lungs' defense system and allowed particles to become deeply embedded, Cahill says.

David Worby, a lawyer in White Plains, N.Y., represents about 8,000 clients with health problems who are suing supervisors, the EPA, the Port Authority of New York & New Jersey, contractors and others involved in the cleanup. He says more than 50 families have lost loved ones due to their Twin Towers work. No trial dates have been set.

"There are thousands of people who will get cancer and will die from this, and the government isn't doing anything," Worby says. "Every week I get one or two calls from a cop saying, 'What do I do for my wife and kids? I've just been diagnosed with leukemia or sarcoidosis (an inflammation that creates scar tissue, often in the lungs).' "

The Port Authority declined to comment on any pending litigation.

There has been financial assistance, including a $125 million federal package that will help fund a health registry of World Trade Center first responders and nearby residents. The money includes $75 million for screenings, exams and treatment for rescue and recovery workers, as well as $50 million to the New York State Uninsured Employers Fund for reimbursement of 9/11-related claims. But some, such as Mount Sinai's Herbert, say more will be needed, because even a few severe illnesses can run up staggering medical costs. An April study from the Centers for Disease Control and Prevention found more than half of survivors reported new or worsening respiratory symptoms after the attacks.

EPA says it gave help

EPA officials say in a statement that the agency "provided masks and goggles for rescuers and crew workers. EPA also encouraged rescue workers to wet down the debris to help protect themselves from asbestos, smoke and dust."

The agency says it provided more than 22,000 respirators, more than 32,000 respirator cartridges and other protective gear and emphasized the need for respiratory protection at daily operations meetings at the site.

"As our nation continues its effort to keep Americans safe from future attacks on our country, EPA remains passionately committed to protecting the health of our citizens and our environment," the agency said in a statement.

But the EPA and other federal offices are coming under criticism for their response.

In an 82-page pretrial ruling in a class-action lawsuit filed by residents and workers in the area, U.S. District Court Judge Deborah Batts said Whitman's "deliberate and misleading" statements about the air quality "shocks the conscience. "

She also said in her February opinion that the EPA knew as soon as Sept. 12, 2001 — the day after the attack — that one of the first air samples contained an asbestos level four times higher than the EPA threshold for danger. The judge was ruling on motions to dismiss counts in the case; Batts agreed to let the lawsuit continue.

Whitman responded with a release that said, "every action taken by the EPA during the response to this horrific event was designed to provide the most comprehensive protection and the most accurate information to the residents of Manhattan. To imply otherwise is completely inaccurate."
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Air Sickness
How microscopic dust particles cause subtle but serious harm

Aug. 2, 2003
Janet Raloff

On Oct. 26, 1948, a temperature inversion laid a blanket of cold, stagnant air over Donora, Pa., a tiny mill town on the Monongahela River. Over the next 5 days, the buildup of pollution cloaked the sun, sometimes restricting vision to just a few feet. Twenty people died outright and 50 more perished within a month from lingering health damage, says consulting epidemiologist Devra Davis, a former Donora resident whose own family survived the tragedy.

As bad as her hometown's pollution had been, its impact would pale against a 5-day killer smog that settled on London in December 1952. It killed some 12,000 people within 3 months, according to calculations in a June 2001 report by Davis and Michelle L. Bell of Johns Hopkins University in Baltimore. "With a death rate more than three times the norm for this period, the London fog of 1952 is widely regarded as a catalyst for the study of air pollution epidemiology," the pair noted.

That science would eventually show that even the diffuse dust wafting in seemingly clear air could kill. Its victims are just harder to identify than those in the London and Donora catastrophes because most who succumb are elderly or already in ill health. Indeed, a trailblazing 1991 analysis by Joel Schwartz, then at the Environmental Protection Agency, concluded that some 60,000 U.S. residents die from heart attacks and respiratory problems each year because of the effects of airborne dust at concentrations within federal pollution limits (SN: 4/6/91, p. 212).

Stunning as those numbers were at first, they're now accepted by most researchers. In that 1991 study and subsequent ones, Schwartz, now at the Harvard School of Public Health in Boston, has shown that community death rates rise and fall nearly in lock-step with local changes in concentrations of tiny dust particles—even when concentrations of those particulates are just one-quarter of the federal limit for outdoor air.

Yet more than a decade later, nagging questions remain: What makes dust and smoke particles, especially small ones, toxic? Is particulate matter, as scientists call it, inherently poisonous, regardless of its composition? Or does a large surface area per unit mass make those particles robust vehicles for ferrying toxicants such as metal atoms deep into the lungs?

In the past 2 years, a flurry of new data has finally begun answering these questions. The research links the greatest harm to the tiniest dust: particulate matter no more than 2.5 micrometers in diameter, called the PM-2.5 fraction. Some studies suggest that the most dangerous of all may be ultrafines, particles less than 0.1 micrometer across—a class of dust that environmental studies and regulations have generally ignored.

Remodeled airways

Although most people who die from particulate pollution had heart disease or respiratory problems, the new data are showing that even young and healthy people aren't immune to the violence that dust can perpetrate on lung tissue.

In Fresno, Calif., for instance, outwardly robust people routinely harbor damage in their lungs' small airways, setting the stage for respiratory and cardiovascular disease. These lung effects appear to trace to Fresno's high level of PM-2.5 pollution, which is as bad as that in Los Angeles and worse than that in nearly any other U.S. city, according to Kent E. Pinkerton of the University of California, Davis and his colleagues. They surveyed the airways of more than 80 men who had been longtime residents of Fresno—many of them in their 20s to 40s—who died from auto accidents and other events unrelated to pollution.

Pinkerton's team found that PM-2.5 has little effect on the lungs' larger passages but injures the deeper, smaller, thin-walled bronchioles that mark where the body begins to extract oxygen from air. The damage was apparently caused by the ravages of molecular fragments called free radicals. The affected tissue exhibited a kind of scarring called fibrosis and an abnormal thickening, two features that make breathing more difficult.

To confirm the role of particulate pollution in these subtle changes to the lung, Pinkerton's colleague Kevin R. Smith exposed young-adult rats for 4 hours on 3 consecutive days to air deliberately concentrated with the particulates in Fresno's atmosphere. The amount of PM-2.5 in the test air, Pinkerton notes, reflected "what can exist in Fresno on bad-air days."

After the exposures, Smith examined areas of the rats' lungs and extracted unusually large numbers of inflammatory cells, called neutrophils, as well as hosts of dead cells.

"It's not unusual to see an occasional dead cell" in the lungs of rats that had breathed only clean air, Pinkerton notes, but the dust-exposed rats showed many dead lung cells, including macrophages—the organ's housekeeping cells. Because macrophages normally gobble up cellular trash such as pollutant particles, their loss could prove important, the Davis team notes in the June Environmental Health Perspectives.

In the May issue of that journal, Andrew Churg of the University of British Columbia in Vancouver and his colleagues report similar findings in the autopsied lungs of 11 nonsmoking women from Mexico City, but not in an equal number from Vancouver. Though the Canadian city's air is relatively clear of particulates, Mexico City's air carries a dense haze of fine dust much of the year.

SOOTY RESIDUES. This chain of ultrafine particles came from mucus lining an airway of a nonsmoking, lifetime resident of Mexico City. The sooty, submicron-scale spheres appear to be diesel-exhaust particles.
Churg/Univ. of British Columbia

The scientists focused on the lungs' smallest, oxygen-absorbing airways. Compared with those from the Canadian women, the tiny airways from residents of Mexico City "were very abnormal," Churg says. They were twisted and exhibited significantly more fibrosis and thickness than normal lung tissue. "A heavy smoker could have airways that look very much the same," he told Science News.

Churg's colleague David Bates plans to test whether the effects the team documented translate into breathing problems in healthy Mexico City adults.

Lilian Calderón-Garcidueñas of the University of North Carolina at Chapel Hill says she knows what Bates will find. At the Experimental Biology meeting in San Diego last April, she documented mildly obstructed breathing in 10 percent of the 174 ostensibly healthy Mexico City children she examined. All the children came from middle- to upper-class nonsmoking families living where the air wasn't the city's dustiest.

Heart of the matter

Despite the natural expectation that lungs should be especially vulnerable to dust, "the worst effects, it turns out, are on the cardiovascular system," observes particle toxicologist Ken Donaldson of the University of Edinburgh.

Some of the most intriguing clues to what underlies these effects are emerging from studies on endothelin. This small protein, produced in healthy lungs, ordinarily prompts blood vessels to constrict to maintain proper blood pressure.

Renaud Vincent of Health Canada in Ottawa, Ont., and his colleagues had been wondering what makes some people particularly vulnerable to an increase in pollution, even in a relatively unpolluted Canadian city. To find out, the researchers exposed healthy volunteers to high concentrations of PM-2.5. They found that endothelin concentrations doubled in healthy people's blood when their exposures tripled from 50 micrograms per cubic meter (µg/m3) to 150 µg/m3, a range typical for the world's most polluted cities.

Although the endothelin jolt didn't hurt these healthy volunteers, previous studies have shown that people with artery-clogging atherosclerosis have a higher risk of dying after a heart attack if they had endothelin concentrations comparable to the spikes observed in the volunteers' blood.

Interestingly, Vincent notes, his team could trigger increases of endothelin only with the kind of dirty dust usually encountered outside—particles that carry some chemical hitchhikers, including metals and hydrocarbons. When the researchers washed the particles to remove those hitchhikers, the PM-2.5 exposures had no impact on blood concentrations of endothelin.

Harvard School of Public Health scientists also have begun exploring dust's cardiovascular effects. Gregory A. Wellenius and his colleagues exposed dogs to either clean filtered air or air seeded with 30 times the concentration of particulates that local outdoor air carried that day. The exposures lasted 6 hours on 3 or 4 consecutive days.

Right after each exposure, the researchers simulated a heart attack in the dogs by constricting a surgically implanted balloon that temporarily shut off a coronary artery. During this blockage, the researchers measured the heart's growing oxygen debt.

The debt was significantly larger in animals that had been exposed to fine airborne dust, the scientists reported in the April Environmental Health Perspectives. A dog's other coronary arteries couldn't dilate as well and couldn't compensate for the blocked vessel if the animal was inhaling particulates, Wellenius speculates. Such a reaction is "entirely consistent" with an endothelin boost from exposure to particulate pollution, he says.

A nose for clues

The collective message from the 200-or-so Mexico City mongrels that Calderón-Garcidueñas and her colleagues studied is also alarming.

A neuropathologist, she was concerned that if dust could damage lung tissue, it might also break down the capacity of nasal passages to block substances from entering the brain. She now reports tracing metals associated with fossil fuel combustion—chiefly vanadium and nickel—from the dogs' nasal tissue, through the olfactory bulb, and into the frontal lobe and hippocampus of the animals' brains.

Because such metals can foster damage by generating free radicals, Calderón-Garcidueñas looked for signs of brain changes in dogs living in areas with heavy particulate pollution.

Dogs often serve as a model for human age-related cognitive impairments. Some dogs at age 10 and older develop the waxy brain plaques characteristic of Alzheimer's disease (SN: 11/3/01, p. 286: Available to subscribers at http://www.sciencenews.org/20011103/bob17.asp). "In Mexico City," Calderón-Garcidueñas told Science News, "we are seeing [plaque] pathology in 11-month-old pups"—a dramatic acceleration in the development of the signature of Alzheimer's disease.

These data are "definitely worrisome," she says, especially in light of her preliminary findings of a similar breakdown in the nasal tissue of many people living in Mexico City.

Another new study in mice, this one by EPA scientists, suggests that particulates do their harm via the metals they sometimes carry. They found signs that exposure to metal-laden PM-2.5 aggravates asthma much more than does relatively metalfree dust.

Stephen H. Gavett of the agency's Research Triangle Park, N.C., laboratory and his colleagues used dust collected in two eastern German towns—one an industrial community polluted with metals and other combustion products and the other a farm village with relatively clean air. The metal-rich dust, gathered by Joachim Heinrich of the GSF Institute of Epidemiology in Neuherberg, Germany, proved far more potent in aggravating asthmatic constrictions of an animal's airways, the researchers will report in the September Environmental Health Perspectives.

Ultrafines, ultrabad?

If such studies suggest that the composition of inhaled particles affects their toxicity, other findings indicate that particle size can greatly exacerbate the problem.

In studies with isolated lung cells, for example, ultrafine particles proved to be between 10 and 50 times as potent as PM-2.5 or PM-10 particles in inducing free-radical damage, such as inflammation. Andre Nel of the University of California, Los Angeles and his team reported their findings in the April Environmental Health Perspectives.

Nel's team also found that ultrafine particles from urban air carry far more toxic combustion hydrocarbons on their surface, per unit mass, than larger particles do. Further probing showed that the smaller motes tend to lodge in cells' mitochondria, the organelles that generate power. The particles turn the mitochondria into "functionless bags," says Nel. And when these powerhouses die, he says, so do the cells they power.

Donaldson has tested "particles that are completely naked"—motes of pure carbon or titanium dioxide, for instance—and shown they cause no damage when delivered to rat lungs as 10-micrometer-wide particles. But crush them into submicron pieces, he says, and "they become highly inflammogenic to the lungs."

Why? Lung-defending macrophages can easily catch and discard the occasional big particle that gets lobbed their way. Exposing the lungs to large numbers of the smallest particles, however, "may completely overwhelm their defenses," Donaldson says. His team's data support that scenario.

After decades of research, says Donaldson, toxicologists are still discovering ways that fine dust particles can kill. And as the dust particles in their sights get ever smaller, the challenge of controlling their release gets ever larger.

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Dust Rules

A finer standard governing particulate pollution is on the horizon

Environmental agencies around the world today regulate dusty pollutants on the basis of mass—not chemistry—and most governments focus on the particles easiest to catch and quantify: those that are 10 micrometers across (the PM-10 fraction), rather than 2.5-micrometer particles (PM-2.5) and smaller ones.

Seven years ago, the U.S. Environmental Protection Agency announced it would soon require states to regulate airborne concentrations of PM-2.5 pollution in recognition of the smaller particles' significantly greater toxicity than larger particles and ability to move far deeper into the lungs, (SN: 12/21/96, p. 410). Almost immediately, the agency was sued by several industries that would be affected.

It took a Supreme Court ruling 2 years ago to get the regulations back on track (SN: 3/10/01, p. 159: Available to subscribers at http://www.sciencenews.org/20010310/note17.asp). Yet "we're definitely several years away" from enforcement of any regulation limiting PM-2.5 pollution, says EPA spokesman Dave Deegan in Washington, D.C.

So, for now, federal law prohibits PM-10 concentrations in air from exceeding an average of 150 micrograms per cubic meter (µg/m3) over any 24-hour period or a 50 µg/m3 daily average over an entire year. When PM-2.5 rules do go into effect, they'll restrict the 24-hour average air concentration of those small particles in any city to 65 µg/m3 and the annual average concentration to just 15 µg/m3.

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