Bookshelf: 'Toxic Truth'

Sometimes it takes an SOB to get anything accomplished, especially against steep odds, and the battle to protect children from lead was especially uphill. Anyone who cares about children’s brains—for lead is a potent neurotoxin—can therefore thank two men who were arrogant, abrasive, and uncharitable with colleagues who did not see things their way. One of them, geochemist Clair Patterson of Caltech, was well known for insisting he was right, and for pointing out to others in great detail all of the mistakes and limitations in their work. The other, psychiatrist/epidemiologist Herbert Needleman of the University of Pittsburgh, was impatient, passionate about his science and social justice, and inclined to divide the world into those who were with him and those who were not, and not to waste much effort trying to get along with the latter.

With protagonists like this, a new book by journalist (and my former Newsweek colleague) Lydia Denworth called Toxic Truth, reaching bookstores next week, manages to do something else that has steep odds against it: make the process of scientific research riveting. She chronicles the fight to prove that lead in the environment was poisoning children’s developing brains, and then the fight to reduce lead exposure. While the latter struggle still goes on, the former was won in the 1970s thanks to Patterson and Needleman. It’s sort of a dual biography, tracing the two men’s scientific careers and discoveries, and recounting the political skirmishes and controversies that embroiled them.

Patterson’s early research sought to determine the age of the earth, using lead isotope ratios in ancient rocks. (He is credited with discovering, in 1953, the age of Earth, 4.55 billion years.) His success was based on the ability to measure, very accurately, tiny differences in the amounts of different isotopes. When his initial efforts to do that produced clearly erroneous results, Patterson discovered that everything in his laboratory—glassware, reagents, tabletops, floors, walls—was contaminated with lead, brought in with the air, itself contaminated with the exhaust of millions of cars burning leaded gasoline. Within a decade, he had amassed enough evidence to conclude that most of the lead in plants and animals—and about 99 percent of the lead in the human body—came from pollution. Increasing human exposure to lead 100-fold above natural background levels, he argued in 1965, could not be good for health.

This was not a message the lead industry or mainstream toxicologists wanted to hear. Although lead poisoning had been known since ancient times (it was thought to have contributed to the fall of Rome, where the wealthy and powerful drank wine stored in lead-lined casks, and drew water through lead pipes), most scientists in the 1960s insisted that the amounts of lead in our bodies were far too low to have any adverse effects. Industry spokesmen described the amounts of lead in Americans’ bodies as “normal, natural background levels.” The petroleum industry, which funded some of Patterson’s research, cut him off as soon as he pointed the finger at leaded gasoline as a health hazard. And the establishment lead research community dismissed his work. It threatened to overturn most of their own accepted wisdom, and nobody could replicate his findings—his techniques gave him a unique capability to see things others could not see.

Patterson, however, never doubted that he was correct, and he persisted—amassing a mountain of evidence that began to convince doubters.  Ironically, when he died in 1995, Patterson, long ignored by many of researchers and reviled by others as a “troublemaker,” was convinced he had failed; he did not know that within a few years his work would be accepted as incontrovertible fact, and cited as a basis for aggressive lead-control policies.

Needleman, working at Children’s Hospital in Philadelphia, was often consulted on cases where a patient had behavioral problems or learning disabilities. After encountering a few cases of lead poisoning among the clinic’s low-income patients, he began testing children’s blood for lead. He was astonished at the number who had high lead levels, which he realized were associated with poverty: old, run-down inner-city housing was filled with deteriorating lead paint, lead in soils from industries and auto exhaust, and old lead plumbing.

A 1979 study by Needleman and colleagues compared children’s performance on a dozen indices of learning and classroom behavior with the amounts of lead in their baby teeth. The results were striking: For each increment of lead exposure, performance on intelligence and learning-behavior tasks decreased. These were not children who had lead poisoning; they were normal kids, with no overt symptoms, with lead levels typical of kids in any urban area. Published in the New England Journal of Medicine in 1979, it suggested that, just as Patterson had speculated 14 years earlier, we were all adversely affected by lead, at least when we were young, and even the “normal” levels of lead in our industrialized environment could damage the developing brain.

The lead industry and its friends reacted as you'd expect. They attacked the study on scientific grounds, questioning its methodology and demanding that it not be accepted as valid until replicated by others. (Sound familiar? See phthalates, bisphenol A, . . . ) But within a few years, the results were confirmed by different teams in other countries, and ultimately more than a dozen studies would support Needleman’s observations.

But controversy persisted. When the U.S. EPA cited Needleman’s work as a basis for its phase-out of lead in gasoline, in 1983, the lead industry and a scientist named Claire Ernhart challenged Needleman’s study, arguing that its data did not support its conclusions. The EPA sponsored an independent re-analysis of the data, which reaffirmed the original conclusions.

But still it didn’t stop. In 1992, Ernhart and a colleague accused Needleman of scientific misconduct, claiming he had manipulated data and falsified results in his 1979 paper. A hearing was held at the University of Pittsburgh (where Needleman worked at the time), and he was found not to have engaged in misconduct. Still, his critics would not let go. They filed a formal complaint with the federal Office of Research Integrity alleging scientific misconduct. Again, after an extensive investigation, Needleman was cleared.

It was a long battle, but lead was phased out of gasoline, lead-soldered food cans were replaced with lead-free containers, and steps were taken to reduce lead in drinking water. The use of lead in new paint was banned, although old lead paint still remains in place in millions of older homes. The average American’s exposure to lead is now at least 95 percent lower than the 1960s “normal,” and the number of children with elevated blood lead levels has been markedly reduced. The problem has not been totally solved, but it has been shrunken and contained, and Denworth’s fascinating historical, biographical, scientific and political saga shows how we got even this far. She suggests, too, that what happened with lead has happened again and again—initial scientific discoveries suggesting a hazard are challenged by industry or skeptical researchers. PR techniques are used to discredit their research, and denial dominates the official response until the evidence is overwhelming. Even then, action is taken only grudgingly, with great deference to avoid “unacceptable” economic impacts.

Pick your poison—phthalates in toys, methylmercury in fish, pesticide residues in foods, carbon dioxide and climate change, the list goes on—and the pattern looks familiar. The amazing thing is that industry gets away with it time and again. As Santayana said, those who forget the lessons of history are condemned to repeat it.