Back in the early 1920s, the U.S. automobile industry had a problem. The public wanted cars that would go faster, but the industry was stuck with internal-combustion engines that had a maddening tendency to "knock," rather than speed up, whenever a driver pressed the accelerator to the floor.
Then, in 1922, came a breakthrough. A General Motors research team, headed by Thomas Midgley (soon to be known as the "Father of Ethyl Gas"), perfected a gasoline additive that seemed to possess magical qualities. It eliminated knock, increased engine compression, and delivered the higher speeds that everyone wanted.
There was only one hitch, and that was the evidence suggesting that the additive-tetraethyl lead-was dangerous. So when GM and its big chemical partner Du Pont announced in 1924 that they were launching a venture called the Ethyl Corporation to manufacture and market tetraethyl lead (TEL), a major outcry from scientists, public-health specialists, and labor leaders ensued. That same year, a terrible disaster among workers at an experimental TEL plant operated by Standard Oil of New Jersey left at least five dead and thirty-five others suffering from tremors, palsies, and hallucinations-the neurological symptoms of lead poisoning. The press soon dubbed the substance "loony gas."
The question was, What would this stuff do to the public at large? Those scientists not already in the employ of the automobile or petrochemical industries expressed horror at the prospect of hundreds of thousands of pounds of lead getting released directly into the air of American cities. But the officials at Ethyl felt differently and argued that the levels of lead in the air would be too low to affect anyone. One company representative told a special conference convened by the U.S. surgeon general that TEL was an "apparent gift of God." At a news conference, Midgley dramatically illustrated how safe TEL would be for workers to handle, when he instructed an attendant to bring him some pure tetraethyl lead, in which he proceeded to wash his hands. "I'm not taking any chance whatever," he announced to reporters who were present. "Nor would I take any chance doing that every day." What Midgley did not care to mention was that, only the year before, he had to take a prolonged leave from work in order to recover from lead poisoning.
After all sides had been heard from, including those who warned that leaded gas would severely endanger the public, the government chose to side with Ethyl.
Seven decades later, lead contamination has spread to virtually every corner of the planet, with vehicle emissions blamed for an estimated 80 percent of it. There is no longer much debate over lead's deleterious nature. Even at very low levels, it is known to cause irreversible brain damage, developmental problems, and behavioral abnormalities in children. But since TEL had been eliminated from most U.S. gasoline over the past seventeen years, its story would mainly be of historical interests, were it not for the two little-known facts.
First,
the Ethyl Corporation quietly continues to manufacture up to sixty million
pounds of TEL a year at a plant in Canada, and, along with two other
operations, sells the toxic additive throughout the Third World. Lead levels
in many places, including Mexico City and Jakarta, have reached alarming
levels, threatening an entire generation of people with serious
central-nervous-system damage. (See box below.)
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Second, just as lead levels in the environment and in children are finally dropping in the United States, Ethyl Corporation is carefully preparing to get approval from the government for a new gasoline additive-in a campaign eerily reminiscent of Ethyl's lead-related strategy seventy years ago.
The new substance is MMT, or methylcyclopentadienyl manganese tricarbonyl, another compound that has as its key ingredient a heavy metal-this time, manganese. Again, there are alarming reports of brain diseases among those who mine or process it, and voices of concern from those knowledgeable about its potential public-health effects. Again, the evidence points to a particularly pernicious impact on children and the unborn.
And once again, Ethyl Corporation believes it will prevail in putting a new additive in your tank. If things go according to Ethyl's plan, manganese will likely be coming out of American tail pipes as early as next year, long before anyone can be certain of how dangerous it is.
Likely, that is, unless the relatively obscure research of a feisty, Scotland-born, Canadian neurotoxicologist named John Donaldson reaches center stage.
For the past thirty years, John Donaldson has been studying how brain cells die. In the process, he and his colleagues have documented that, when enough neurons in strategic areas of the brain have perished, symptoms such as tremors and muscular rigidity, similar to those of Parkinson's disease, are the probable result.
Much of Donaldson's research has centered on determining how the normal cell-dying process brought about by aging is accelerated by toxic "hits," which perhaps go as far back as infancy or even the womb. "An early toxic insult may act like a computer virus that is inserted into a program," Donaldson explains. "The effects would not produce symptoms until at least mid-life." In Parkinson's patients, for example, symptoms don't usually appear until 75 percent of the brain cells that produce a basic chemical called dopamine have been destroyed.
Donaldson, who started his work at the University of Manitoba and is now a private consultant in toxicology in the Ottawa area, had been conducting his research for about fifteen years when, in the mid-1970s, he came across reports about manganese that aroused his curiosity. There are a number of reasons why the metal had not been a prime suspect in brain disease. It is one of the elements essential for healthy human development and is widely distributed through water, soil, and air. In fact, most people's daily diets are rich in manganese-wheat, rice, and tea are examples-and its intake, when ingested, is generally well regulated by the body.
Donaldson became suspicious when he read reports of hallucinations, similar to those suffered by Parkinson's patients, among miners, ore processors, welders, and battery makers exposed to high levels of manganese in Japan, Chile, Italy, Morocco, Mexico, Russia, and Romania. In addition, biochemical analysis of central-nervous-system tissue in humans and monkeys poisoned by manganese showed that the metal reduced dopamine levels, causing brain cells to die. The data suggested that manganese could target the region of the brain known as substantia nigra, where dopamine-containing cells originate and then project into the basal ganglia region.
Brain-chemistry disruptions and cell death in these regions appear crucial to the development of other progressive neurological disorders, including amyotrophic lateral sclerosis (Lou Gehrig's disease), Huntington's chorea, and Alzheimer's. Discovering the links between manganese and brain disorders, Donaldson found himself reflecting on the metal's ancient Greek name, manganin, which means the occult, voodoo, or black magic.
Slowly, Donaldson and other researchers came to believe that, when inhaled, low doses of manganese are transformed in the brain to trigger a complex chemical process resulting in cell death. This, if confirmed, might explain why manganese in the air could be dangerous, while in food it is generally not. Probably most vulnerable to the metal's toxic "hit" are infants, young children, and women, whose defense systems against the retention of excess manganese have been shown to be less efficient. For these groups, researchers warn, high levels of ingested manganese may be potentially harmful, as well.
"What we're talking about here is that manganese is insidious, a stealth toxin, hitting early and perhaps often and then revealing its damage as we get older," Donaldson says. His studies on animals suggest that moderate doses of the metal may disrupt sex-hormone levels and cause impotence. There are also studies of prisoners that connect high levels of manganese in human hair with violent behavior, though Donaldson cautions that "a lot of work needs to be done before we start concluding things about manganese and violence." (See box for a complete list of the metal's potential health impacts.)
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When he first began investigating the link between exposure to manganese and brain-cell death, Donaldson considered the issue mainly an intriguing scientific challenge. But that was before he ran into the folks at the Ethyl Corporation and found out about their efforts to bring to the public their new apparent gift of God.
Prior to passage of the Clean Air Act in 1977, Ethyl had been able to sell some MMT to U.S. refiners. But back then, the substance's use was limited to the relatively few companies that needed it to obtain an extra-octane boost over what the legal limit for TEL could achieve. MMT was also used in some of the unleaded gasolines that came onto the market in the 1970s, but that stopped when the Clean Air Act put the onus on Ethyl to prove that its additive would not lead to the failure of new emissions-control systems.
Since that time, the EPA and Ethyl have spent most of their time battling over this technical issue-and not over health questions.
So far, on three occasions the EPA has denied Ethyl's requests for approval of MMT. The EPA's latest ruling, however, in January, found that Ethyl's test data met the agency's technical criteria, except for some discrepancies between emissions data supplied by Ethyl and data developed by the Ford Motor Company.
Even though the EPA had sponsored a conference last year that raised serious questions about the potential health problems associated with MMT, those following the behind-the-scenes jockeying between the agency and Ethyl were alarmed by the January ruling. The particular EPA review process, invoked by Ethyl's application, was established by the Clean Air Act. It addresses only vehicle and emissions standards and does not, according to Ethyl, require the evaluation of health data. This claim worries environmentalists. "It would be a gross abuse of EPA discretion if [the agency] didn't use its full powers under the Clean Air Act," says Karen Florini, a lawyer with the Environmental Defense Fund.
But Barry Nussbaum, chief of the EPA's field operations and compliance policy branch, says it is not clear that the agency's discretion in this case can include the consideration of health data: "I'll be frank with you, it's not a closed legal issue. There is no simple yes or no to that one."
"We'd be willing to sit down with Ethyl and try and work out the differences between their data and Ford's," says Richard Wilson, director of the EPA office that is handling the proposal. "We've told them that privately and publicly. We're sympathetic to their problem." EPA administrator William K. Reilly concurs. "Ethyl's cooperation with the agency...has been excellent," Reilly said in January. Ethyl vice-president, Gary Ter Haar, who heads up the company's MMT project, says that the company is willing to conduct "some reasonable research" to resolve the data discrepancy and suggests that the "EPA could allow us to use the product and stipulate certain experiments." But he warns that Ethyl will take the agency to court if it has to in order to get MMT into U.S. gas tanks more quickly. "We're going to pursue certification [of MMT] with all the energy we have," vows Ter Haar, "whatever that requires-including continued discussions with EPA, legal action, and whatever action it takes to pursue this as aggressively as we can." (In February, Ethyl filed a "petition for review" of the EPA's latest denial of its application in Federal Appeals Court in Washington, D.C.)
Ter Haar rejects any discussion of health issues. As far as he is concerned, that file is closed, because MMT emissions would be too low to cause any possible sort of health problem. That, of course, is similar to what his predecessors said seventy years ago about TEL.
In fact, Ethyl argues that MMT, rather than proving a threat to health, will actually help to clean up air pollution. On the basis of its test results, the company contends that, since fuel burns more efficiently with the additive, MMT will actually decrease nitrogen oxide and carbon monoxide emissions and make possible lower levels of the carcinogenic substance benzene in gasoline. Altogether, Ethyl's tests indicate, the use of MMT could remove 1.7 billion pounds of pollutants from U.S. air annually by 1999, and save up to thirty million barrels of crude oil a year.
Added to these potential environmental benefits, says Ter Haar, is the company's position that "pure and simple, the product does not cause adverse [health] effects."
John Donaldson and a host of other scientists disagree.
In 1987, Donaldson consolidated all of his knowledge about manganese into a book chapter commissioned by the National Research Council of Canada. In his draft, which was submitted to the council before being revised for publication, he observed that the health risks of MMT had thus far received only cursory attention, despite the additive's use in Canadian gasoline for a decade.
Soon he began receiving calls from the Ethyl Corporation, leading him to conclude that someone in the Canadian government had sent Ethyl his manuscript. But Ethyl, then preparing for the third time to obtain EPA approval to use the additive in the United States, asked him to send his ideas for research, which he decided to do.
Donaldson said that the "obvious and critical studies" that were necessary would involve determining how monkeys of different ages process various forms of inhaled manganese. Periodic brain scans would track the results over a year's time, and special attention would be paid to the effects on dopamine-containing cells.
Citing his previous studies, Donaldson suggested that a "magic-like transformation" of low-dose manganese occurs in the basal ganglia region of the brain, triggering the production of chemical assassins known as "free radicals," which can damage the cells that make dopamine. "A low-dose hit of manganese going to the right place might be all that would be needed," he said.
This scenario is supported by other scientists, including Alejandro Daniels of the large pharmaceutical company Burroughs Wellcome. "I totally agree with Donaldson," he says, on the basis of his own animal research.
Michael Ashner, a neurotoxicologist at Albany Medical College in New York, also backs Donaldson's theory. Ashner's rat studies have demonstrated that iron deficiencies can lead to higher concentrations of manganese in the brain. This is worrisome because iron deficiency is a serious problem worldwide. It is particularly likely to affect low-income women and children in inner cities, where MMT levels in air tend to be highest. Infants and young children absorb and retain more manganese than other people do, and iron deficiency plays a similar role in the epidemic of lead poisoning among inner-city poor. That is one especially cruel aspect of both additives-they seem to target the most vulnerable members of society for damage.
"Much more research will have to be done to understand better the interplay of iron and manganese and possibly other metals in brain disorders," Ashner cautions. "In the meantime, we shouldn't be jumping the gun by rushing into using manganese in gasoline. The first thing we ought to determine is a safe level for manganese. We really don't have one now."
Donaldson agrees: "It makes no bloody sense for Ethyl to put a neurotoxin into the air before we have a good grasp of what it can do at low levels." He recommended that Ethyl conduct studies on the reproductive system to determine how manganese affects sperm levels, the maturation of testes in young animals, and mating habits. In some studies of the wives of manganese-foundry workers, he says, "there were increases reported in stillbirths and spontaneous abortions, and this is something we need to know more about."
But his cooperation with Ethyl did not produce results. The company opted not to take Donaldson's advice, because, Ter Haar says, carefully, "We never thought a program with Donaldson would have a chance at legitimate success."
Last year, when the EPA held the conference to review the research done on the health effects of manganese, there was no hint of whether this would affect its MMT decision. Kathryn Mahaffey, a toxicologist with the National Institute of Environmental Health Sciences, who attended the sessions, says: "Very little is known about the effects of exposure to low-to-moderate doses of manganese. Anyone who thinks we have the answers to these questions is not looking at the issue carefully."
The biggest uncertainty of all is whether that lack of knowledge will be used as a reason to approve the use of MMT, or to delay it.
One basic question lurks behind the debate every time a government agency considers banning a substance that seems potentially harmful to human health and the environment. Despite all the environmental legislation of the past two decades, that question-Is it up to the manufacturer to prove a product safe, or the government to prove it dangerous? - remains unresolved. Those primarily concerned with industrial progress argue that products should be considered innocent until proven guilty; those who place their highest priorities on health and safety say that the burden of proof should lie with the private interests who profit from government approval.
When the predecessors of today's EPA officials faced this dilemma back in the 1920s, they addressed it by creating what was supposed to be an impartial scientific inquiry into TEL, but what was in fact an inquiry carefully controlled by industry: General Motors was allowed to fund (as well as to review and control the release of) a government study conducted by the Bureau of Mines, which, not surprisingly, determined TEL to be safe. In addition, certain established public-health specialists were secretly recruited by industry to speak out in favor of TEL.
Today, everything has changed and nothing has changed. The essential question of whether Ethyl has to prove MMT safe or the EPA has to prove it dangerous is still an open one. It appears that the ambiguity that worked for Ethyl in the past may be working again.
The EPA's position seems to be that the data necessary to make a proper risk assessment is not available. As to any difference this might make in its MMT ruling, the agency remains silent.
Speaking for the EPA, Richard Wilson explains: "Our health researchers would like to see some additional data to make them feel more comfortable. They don't think it's a major health threat. It's one of those handwringers. If that was the only issue, you'd have to decide if the uncertainty was enough to tell them they can't market it until they do the testing, or let them go ahead and require them to do testing, or just let them go ahead and let well enough be. In these types of issues, you don't decide until you have to decide."
This approach signals danger to those familiar with how TEL originally got into gasoline. Toxicologist Ellen Silbergeld, formerly with the Environmental Defense Fund and now at the University of Maryland, warns: "MMT is exactly lead. All you have to do is substitute the word 'lead' and you'll have what they said [back in 1925]." In each case, Silbergeld points out, no data is available "on the potential cumulative health effects of massive inputs of a toxic metal into the environment." Again, Ethyl argues that the amount of manganese in gasoline is insignificant in health terms but very important for the nation's economy. "As Yogi Berra once said," Silbergeld concludes," 'deja vu all over again.' "
Last year, to back up its position that MMT is safe, Ethyl Corporation sampled twenty-five people in Toronto, including office workers and cab drivers fitted with monitors to measure their exposure. The office workers' manganese levels averaged 0.013 micrograms per cubic meter per workday, and the cab drivers' 0.035 micrograms. Others tested between these two extremes.
The company compared these readings to the "safe level" of 1 microgram per cubic meter set by both the World Health Organization and the California state government on the basis of industrial exposure to the heavy metal. "This is proof that MMT in gasoline poses no health risk," says Ethyl's Ter Haar.
The Toronto test is reminiscent of an earlier study, on lead exposure, which was performed on gas-station attendants and chauffeurs in Dayton and Cincinnati during the 1920s at the instigation of the U.S. surgeon general's office. Though that study demonstrated that low levels of TEL were stored in human tissue, the committee of scientists reviewing the data did not find the results alarming enough to recommend against allowing the substance in gasoline.
Recognizing, however, that the storage of low levels of lead over time might lead to disease, the committee called for a longer-term follow-up study. But it was never performed; instead, government officials went ahead and allowed TEL in gas.
Today, scientists know that it is precisely the buildup of lead in the environment that creates the threat to those most at risk. And, Silbergeld and others warn, the dispersal of manganese via car exhaust risks a replay of the lead disaster.
Much, therefore, rests on how the EPA will rule. If, as Ethyl Corporation hopes, the agency approves the additive, MMT will be here for years to come. Then, even if MMT is eventually established, like TEL, to be a public-health threat, it will be too late for the thousands or millions of people whose capacities for full lives have been reduced by exposure to it. And experience shows that any future battle to get the substance out of gasoline, once it's in, will be a slow and difficult one.
Meanwhile, there is evidence that the phaseout of leaded gas has at least temporarily improved the quality of life for inner-city children. Dr. Sergio Piomelli of Columbia Children's Hospital in New York City recently reported that the number of local kids with elevated levels of lead in their blood has, since the phaseout began, fallen from about thirty thousand to fifteen hundred-a reduction of 95 percent.
The
question now facing the EPA is whether these same children will soon be
breathing a new form of black magic in place of the old.
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