News & Politics » Feature

Up In The Air

In the fight over airborne pollutants, the real stink may be the smell of opposing sides cooking the facts.

by

comment

By Harold Henderson

The day before Thanksgiving, the Environmental Protection Agency announced that it knew how to save 20,000 lives a year: establish and enforce new regulations limiting the number of fine particles in the air.

These tiny foglike particles are really fine, as in invisible. They're more like smoke than dust as we normally think of it. Some solid, some liquid, they come from tailpipes and smokestacks and from chemical reactions in the air. The technical term is PM2.5, which stands for particulate matter 2.5 microns and smaller. They stand accused of causing shortness of breath, chest pains, and coughing; aggravating heart and lung ailments and asthma; increasing emergency room visits and hospital admissions; and--ultimately--killing people before their time.

The agency proposed to allow no more than 50 micrograms per cubic yard averaged over a day, and no more than 15 micrograms averaged over a year. A gram is less than one-twenty-eighth of an ounce, and a microgram is one-thousandth of that, so these amounts are small--but they're still roughly three or four times "natural" levels in the eastern U.S.

EPA has since reduced its estimate of the number of lives the new regulations would save each year to 15,000, citing a "technical error in the characterization of data." Even so, if fine particles are as dangerous as the agency thinks, its new rules would save about as many lives as cutting highway deaths by one-third. (EPA has also proposed tighter limits on ground-level ozone, but did not make such strong claims for that measure. Both proposals are due to be decided on in mid-July.)

Are the charges true? There is no vault in which 15,000 death certificates accumulate every year with the cause of death conveniently labeled as "fine particulate air pollution." Nor have researchers found the biological mechanism by which these particles do their alleged respiratory dirty work. So business and environmental lobbyists mount their well-worn barricades. The Environmental Working Group and Sierra Club say the science behind EPA's proposed standards is "exceptionally powerful and consistent." Stephen Milloy, who coauthored a January 7 Wall Street Journal column criticizing the new standards, regularly refers to the same body of research as "junk." They can't both be right, but they could both be wrong. Chicago's own commissioner of environment, Henry Henderson, thinks they both miss the point.

The battle came to Chicago in the form of a two-day public hearing January 14 and 15. So did a snowstorm. As the white stuff piled up outside, the words piled up inside the mirror-walled, chandelier-lit ballroom of the Midland Hotel.

Congressman Bobby Rush led off in support of the proposed regulations. "Our lives literally depend on it. In Chicago, we have about 3,500 deaths a year from particulates. Under the new standard it would be less than 2,000." Jacky Grimshaw of the Center for Neighborhood Technology invoked her asthmatic nieces and nephews, ages two to seven, in favoring even tougher standards than EPA had proposed.

EPA is practicing "tabloid regulation based on extremist agendas," snarled Mike Wilkins of the Uno-Ven oil refinery southwest of the city. "I'd say I was pleased to be here," he told the hearing officer, "but that would be as disingenuous as you saying you're listening....We reformulate our products, then the rules change. Are they based on proven health concerns? Absolutely not."

"Listen to the doctors, not the polluters," said Dr. Edward Garrity of Loyola University. "We probably know more about these pollutants today than we did about tobacco 30 years ago. EPA should adopt the most protective health standards possible."

I didn't need a scorecard to tell where each new witness would line up. Anyone who said that air pollution has declined would oppose EPA. (Who said these clues were logical?) Anyone who alluded to respiratory problems would speak in favor of the new regs--at least until Kathi Kuehnel came to the table.

"For ten years I spent every Saturday out of doors with my father," she said, "hiking, biking, horseback riding, going to the zoo, looking for fossils. I got my love of the outdoors from him." In the mid-60s the family moved from Colorado to Illinois, and his "breathing problems" got worse. Kuehnel found herself growing up outside emergency wards. Allergy treatment helped him a bit; being stuck in the smoking car on a commuter train was almost lethal. But no diagnosis was ever forthcoming. "He came into the hospital DOA at least two times I can think of." When he did die, in 1978, she was in college, a biology major thinking she might end up working for an environmental group.

"You grow up differently when you face death as a kid," she reflected in an interview after her testimony. "I never got into trouble in high school or college. There was no need to invent problems! Most kids think life is forever; I could always hear the clock ticking."

But Kuehnel can hear other things too. She directs state government relations for Ford Motor Company from an office on North Michigan Avenue. "My life has been touched by lung disease. But I have to look at the other side. I've walked the Second Congressional District"--where Ford's big Taurus plant accounts for about half of the 5,000 employees on the company's Illinois payroll--"with Congressman Jesse Jackson Jr. I've seen the boarded-up malls and industries, what it's like for a child to grow up with no hope for jobs."

It's conceivable--no one will ever know--that Kuehnel's father might have lived to see her graduate from college if Chicago's air had been less polluted. But at the Midland hearing she spoke against the standards intended to clean it up even more. "I'm afraid the science doesn't justify the huge expenditures. We will have burdens that our competitors in [less polluted, exurban] areas won't have. This could be a huge burden on the south side."

Was Kuehnel's testimony crass corporate exploitation of a human tragedy? It didn't strike me that way. It struck me that she just happened to be placed so that she could see two legitimate sides. Just because you care about someone who can't breathe easily doesn't mean you hop on every bandwagon labeled "clean air." It may not be going where you think.

First, some perspective. American air has been getting cleaner for decades, and air pollution isn't the most serious killer human beings face. Even as air pollutants go, tobacco fumes are more dangerous than anyone claims fine particulates to be.

Getting cleaner. In a particularly low point in the debate, Jeffrey St. Clair wrote in the Chicago-based biweekly In These Times (February 3) that "185 different scientific studies support the conclusion that the nation's air is becoming ever more toxic." They don't, and it isn't. Between 1986 and 1995, EPA measurements show that the amount of lead in the air nationwide dropped 78 percent, carbon monoxide 37 percent, sulfur dioxide 37 percent, particulates under 10 microns 22 percent, nitrogen dioxide 14 percent, and ground-level ozone 6 percent. Overall emissions of these "big six" pollutants are estimated to have declined by 29 percent since 1970. (Fine particles are a partial exception if you measure them by long-range visibility. East of the Mississippi, visibility declined greatly during the 1970s and recovered only slightly during the 1980s.)

These facts are inconvenient for environmentalists, who would find it handy to blame rising asthma rates on "increasing" air pollution. Businesses, on the other hand, are happy to cite them--and then to conclude, with impressive illogic, that therefore EPA should do nothing about fine particles.

The big killers. Last year Christopher Murray from the Harvard School of Public Health and Alan Lopez of the World Health Organization published what they call the "Global Burden of Disease Study" (Science, November 1, 1996). In an attempt to set worldwide public health priorities, they quantified the causes of deaths and prolonged disabilities. To measure death and disability by the same yardstick, they calculated Disability-Adjusted Life Years, or DALYs, as "the sum of years of life lost because of premature mortality and years of life lived with disability, adjusted for the severity of the disability." Then they tabulated the worldwide toll from ten selected risk factors in 1990.

The worst was malnutrition, which accounted for almost six million deaths worldwide--11.7 percent of deaths and 16 percent of DALYs. "Poor water supply, sanitation, and hygiene" was the runner-up, blamed for 5.3 percent of deaths and 6.8 percent of DALYs. Then came unsafe sex, tobacco use, alcohol use, occupation, hypertension, "physical inactivity," and illicit drug use. Last on the list was air pollution, blamed for 568,000 deaths worldwide--1.1 percent of total deaths and 0.5 percent of DALYs. The figures indicate that air pollution is by no means a negligible health problem, but for every sign reading Air Pollution Kills there should be at least ten saying Malnutrition Kills.

Smoking, the deadliest air pollution. The American Lung Association estimates 419,000 Americans die of "smoking-related diseases" every year. The most extreme estimate for fine particulates is 64,000.

While environmentalists exaggerate, the business and antiregulation lobbyists lie. They're investing a lot of money to propagandize and lobby against the proposed standards through groups like the Air Quality Standards Coalition and Citizens for a Sound Economy, as is their right. But on current evidence they're not getting a respectable return on their investment.

The most egregious example is a quote repeated by the Chicagoland Chamber of Commerce, the Palatine-based Heartland Institute, and the Reason Foundation. According to these groups, EPA's independent Clean Air Science Advisory Committee (CASAC) said that the agency had failed to "provide a scientifically adequate basis" for setting a fine-particulate standard. CASAC is made up of top epidemiologists, toxicologists, and atmospheric scientists with no other connection to EPA. Such a judgment, if it had in fact been rendered, would have been devastating.

The quotation is accurate. But in no way does it represent the committee's conclusion. It appears in a letter CASAC sent EPA January 5, 1996, commenting on rough drafts of EPA documents summarizing the research on fine particles. CASAC did not reach a conclusion on the fine-particle standard for another five months, and then expressed it in a five-page, single-spaced "closure letter" to EPA administrator Carol Browner on June 13, 1996.

In the June 13 letter CASAC chair George Wolff, who works for General Motors, wrote that the committee had reached "a consensus" that EPA should establish a new fine-particle standard. Nineteen of CASAC's 21 members joined this consensus. In other words they agreed the scientific case against fine particles was strong enough to establish a standard. They did not agree that PM2.5 had been scientifically proven to kill people. (This is a perfectly reasonable position, no matter how the business lobbyists hoot: what good driver waits until a collision is certain to take evasive action?) Nor did the 19 agreeing members of CASAC concur on how low the fine-particle standard should be set. But they had decided that there was adequate scientific basis for it.

The June 13 closure letter shows that EPA staff had managed to strengthen their case between January and June. This letter was readily available to anyone who was interested. But it did not say what Reason, Heartland, or the Chicagoland Chamber wanted it to say. Their flagrant misuse of this evidence casts doubt on their repeated claims to support "sound science" in environmental decision making.

An experiment could settle the scientific issue. But it would be immoral, illegal, and impossible. You'd have to herd matched sets of people with the same lifestyles into two separate cities identical in every respect, except that one had 100 micrograms of fine particles in every cubic meter of air and the other had 5--then wait and see in which city people died sooner.

Failing that, epidemiologists look for real-life situations that come close. At the simplest level, they can see if more people in a given city die or get sick on days when pollution is high ("time series") or compare death rates between more and less polluted cities ("cross section"). More sophisticated and expensive are time-series and cross-sectional studies in which you don't depend on gross death rates, but instead track "cohorts" of individual people as pollution levels vary. In all cases, the more you can rule out interfering factors (people dying of the heat or because they chain-smoked for 40 years), the more reliable the result.

What you get at the end of any such epidemiological study is a number--a "risk ratio" comparing the chance of death (or illness) among the polluted to the chance among the unpolluted. Risk ratios come in all sizes. The U.S. surgeon general's classic 1964 report Smoking and Health summarized seven studies showing that smokers had a risk ratio of 10.8 for lung cancer as compared to nonsmokers. In other words, where 170 nonsmokers would be expected to die of lung cancer, 1,833 smokers did. That is huge. By itself it may not be ironclad proof that smoking "causes" lung cancer in the crudest sense--some nonsmokers died of it too--but at the very least it shows a serious relationship. (Do we know more about fine particles now than we knew about cigarette smoke then? We have more studies now, but the risk ratios are an order of magnitude lower. Flip a coin.)

A 10.8 risk ratio is the epidemiological equivalent of finding pebbles of pure gold on the Lake Michigan shoreline. Epidemiologists normally deal with much smaller risk ratios. If real, they aren't trivial because they affect lots of people--everyone who breathes, in the case of fine particles. But it's no simple matter to tell if they're real.

For instance, Douglas Dockery and colleagues at the Harvard School of Public Health published their "Six Cities Study" in the New England Journal of Medicine December 9, 1993. They followed more than 8,000 people in six towns for 15 years beginning in 1974. The key result: the risk ratio for the city most polluted with fine particles (Steubenville, Ohio) compared with the least polluted (Portage, Wisconsin) was 1.26. That doesn't prove that the fine particles killed, but it's suspicious: the difference between the two cities remains about the same even after the researchers correct for age, sex, cigarette smoking, level of education, body-mass index, and exposure on the job. Holding all those factors constant over the 15-year period, you were still 26 percent more likely to die in Steubenville than in Portage.

This risk ratio is typical of the particle studies. It sounds more definitive than it is, because there are so many more factors you might need to control for, and it takes so little to overwhelm a small risk ratio. It's like trying to listen to a drum and cymbal concert on AM radio during a thunderstorm: there may be a station there, but the noise is almost as loud as the signal. Dissenting epidemiologist Suresh Moolgavkar wrote a letter to the Journal pointing out that the risk ratio for a nonsmoker to die of lung cancer at age 51 as opposed to age 48 is 1.29. Just getting three years older has about the same effect on lung cancer odds as moving from Portage to Steubenville. (Moolgavkar was actually questioning Dockery's control for age, which turned out to be OK.)

Epidemiologists know that risk ratios this small often mean nothing. Most of those interviewed in Science (July 14, 1995) "said they would not take seriously a single study reporting a new potential cause of cancer unless it reported that exposure to the agent in question increased a person's risk by at least a factor of 3--which is to say it carries a risk ratio of 3. Even then, they say, skepticism is in order unless the study was very large and extremely well done and biological data support the hypothesized link."

Well, on particulates we have 86 studies published in the last ten years, though fewer than a quarter of them deal specifically with fine particles. About three-quarters of the 86 find serious health effects. (It is possible that some additional studies finding no effect did not see the light of day. There's an understandable bias among researchers, publishers, and funders in favor of work that shows something.) The 86 studies aren't all carbon copies of one another: there are cohorts, time series, cross sections; studies involving Philadelphia, Boston, Toronto, Detroit, Chicago, Saint Louis, Cincinnati, Kingston (Tennessee), Birmingham (Alabama), the Utah Valley, Los Angeles, and Santa Clara County, California; studies that track health problems ranging from coughing to death. They show "coherent" effects--that is, fine particles correlate with respiratory problems (more reasonable than if they correlated with, say, pancreatic cancer), and they seem to cause more illnesses than deaths (suggesting a typical dose-response relationship).

To put it another way: if fine particles are not the culprit, each new study means that the alternative explanation for the excess mortality must become more complex (and at some point less plausible). In Philadelphia, people might be dying because of sulfur dioxide, not fine particulates. But then in Utah, where there is almost no sulfur dioxide, it would have to be because of carbon monoxide or ozone, not fine particulates. And so on. As Harvard's Douglas Dockery and Joel Schwartz wrote in a November 1995 commentary in the journal Epidemiology (part of their continuing professional duel with Moolgavkar), "We find it difficult to believe that confounding by carbon monoxide in some communities, SO2 in others, and unspecified air pollutants in still other cities would produce effect estimates for particulate air pollution that are so quantitatively similar in these different locations....The challenge to those who question these associations is to present an alternative explanation."

The challenge to those who think fine particles are indeed the culprit is to figure out how they hurt people. "There are no complementary data from toxicologic studies or from acute human exposures to similar levels of respirable particles," reported a committee of the American Thoracic Society in a 1996 "state of the art" report on outdoor air pollution. In other words, fine particles appear to be killing people in general (epidemiology) but to be largely harmless in particular (toxicology). The smaller the risk ratio, the more important it is to resolve this contradiction.

Unfortunately, EPA has not been showing the requisite sense of urgency about further research. In a March 12 letter to administrator Carol Browner, the Clean Air Science Advisory Committee complained that a draft agency report "conveys the notion that the direct causality of PM, and especially PM2.5, in the health effects observed by epidemiology is established." It is not. Worse, "only approximately 5% of EPA's research staff is focused on PM issues. The Panel was unanimous in expressing its strong concern that this level of funding and staffing falls far short of the resources needed." In fact, they said, the agency is devoting more resources to "issues having lesser estimated health and economic impacts."

You might wonder why so many people put themselves through so much grief. A 1995 Harris poll found that 64 percent of the public feels existing air and water quality controls are not strict enough. As the American Lung Association says, "When you can't breathe, nothing else matters." Why worry so much about the science? Why not just err on the safe side?

That rhetorical question makes sense only if you already know which side is safe, and if you are not personally paying the bill. For instance: several epidemiological studies have found that kids in day care (especially under age two) have risk ratios of around 2.0 for things like croup, bronchitis, and wheezing when compared to kids cared for at home. Sure, they're not dying of it--but that is a bigger risk ratio than anyone has found for fine particles. Day care may be more likely to make your toddler sick than fine-particle pollution. So where is the movement to restrict out-of-home child care "just to be on the safe side"?

Business has its own idea of erring on the safe side, and it involves not spending money. Of course regulating fine particles would be a waste if the problem lies elsewhere; that's what the epidemiological debate is about. But when the Chicagoland Chamber of Commerce complains, for instance, that fine-particle regulations will cost between four and nine billion dollars in Chicago alone, it has little credibility. "So far nearly all forms of conservation have cost less than expected," environmental reporter Gregg Easterbrook pointed out in his 1995 book A Moment on the Earth. "When the nationwide conversion to unleaded gasoline began in 1977, petroleum companies predicted price increases of 20 cents per gallon in 1994 cents. Instead refining unleaded gas now costs only an added one cent per gallon. Acid rain permits were expected to sell for $600 to $700 per ton. Instead they are selling for about $150, as controls are costing utilities substantially less than expected." In addition, as Ron Burke of the American Lung Association points out, when the market does not respond so promptly to the regulatory whip, EPA has repeatedly postponed clean-air deadlines for cost reasons.

Where is the "safe side"? Chicago's commissioner of environment, Henry Henderson, gave that question a new twist at the EPA hearing January 14. Assuming that EPA's assessment of the fine-particle research is correct, he told the agency that nevertheless, "Implementation of your proposal as it currently stands will have negative health effects."

Henderson's argument for this paradoxical claim is much like Kathi Kuehnel's. Basically, EPA enforces the Clean Air Act by territory. "Attainment areas"--cities and counties where a given type of air pollution falls below the standard--get off easy. On the other hand, people and businesses in "nonattainment areas" have to sweat, or risk losing federal funds for crucial programs. The six-county Chicago area is a severe nonattainment area for ozone. Thus factories here are considered "major sources" (and required to use specified technologies) if they emit 25 tons of certain ozone-producing chemicals per year. In Rockford or Bloomington or Kendall County, you have to pump out 100 tons--four times as much--to be a major source. Major sources are limited in how they can expand or build new facilities; above a certain threshold they must find another business to offset their added emissions, or relocate to an area where they can pollute more freely. These requirements, too, kick in sooner in the six counties than they do in attainment areas.

Similar restrictions would be imposed for fine particles if the new standard goes through, Henderson fears. He's not arguing that it's bad to control air pollution, or that it costs too much--just that the costs involved are disproportionately borne by industries in established city and suburban areas. EPA implements the Clean Air Act in such a way as to encourage businesses to leave town, or never enter in the first place. "If we are to comply with the new standards," Henderson says, "we have to further regulate the already highly regulated stationary industries...possibly jeopardizing jobs and the city's economic health." This will "drive more companies to the urban fringe, reversing years of progress on brownfields remediation and generating significantly more atmospheric pollution from automotive exhaust."

Ron Burke of the American Lung Association, who takes a backseat to no one as a sprawl fighter, thinks the city would help itself more by making its concerns known during the implementation process for the new rule. Henderson doesn't believe it; he thinks the standards and their implementation are, in effect, one package. If you want to be on the safe side, he says, make sure you're really cleaning the air and not just taking a feel-good whack at polluters. "In order to honestly promise health improvements, you've got to look at it holistically." Why should the federal government promulgate tougher federal standards with one hand while at the same time it allows the CTA--"this wonderful pollution fighting machine"--to decay? Henderson would like EPA to convene an "interdepartmental task force" where EPA, the Department of Transportation, and the Department of Energy together could formulate "a coherent federal approach" to cleanup. "That's what environmentalism is all about--not just setting standards in the abstract without paying attention to how they're implemented."

Art accompanying story in printed newspaper (not available in this archive): Illustration by Carl Kock.

Add a comment