Even the ancient Romans knew lead was a deadly toxin. How did it end up in America’s gas tanks and backyards?
Almost a century ago, at a Main Street service station in Dayton Ohio, the world’s first gallons of leaded gasoline were pumped into the cars of customers who filled their tanks at the Refiners Oil Co. The company prominently announced its new Ethyl gasoline as a “product of the General Motors Research Corporation.” It was February 1923.
Engineer Thomas Midgley and his associates at the General Motors Research Laboratory discovered in 1921 that tetraethyl lead, a compound of metallic lead, could make internal combustion engines run more smoothly and reduce engine knock.
But in the fall of 1922, the U.S. Public Health Service’s William Mansfield Clark, then the division chief of the agency’s hygienic laboratory, wrote a letter warning the agency’s assistant surgeon general that tetraethyl lead was a “serious menace to the public health.”
The U.S. Public Health Service then requested that its Division of Chemistry and Pharmacology investigate, but the division director suggested that the agency should instead obtain the data from the industry itself.
General Motors researchers already knew of a safer alternative to leaded gasoline: ethyl alcohol — also known as ethanol — was among the best anti-knock fuels. It was renewable, nontoxic, and burned more cleanly than gasoline, but couldn’t be patented and therefore offered no profits for GM, according to “The Secret History of Lead” by The Nation’s Jamie Lincoln Kitman.
In late 1922, U.S. Surgeon General H.S. Cumming wrote to Pierre du Pont and asked about the potential health hazards connected to lead gasoline exhaust and the cumulative effect on people who absorb lead daily in small quantities. The DuPont company manufactured and supplied General Motors with tetraethyl lead.
Midgley told Cumming that there was no experimental data, but that General Motors and DuPont were confident that “the average street will probably be so free from lead that it will be impossible to detect it or its absorption,” according to historians Gerald Markowitz and David Rosner.
This was Midgley’s conclusion despite falling ill at the time from working with lead, which compelled him to head to Miami “to get a large supply of fresh air,” according to The Nation.
General Motors subsequently provided the funding to the U.S. Bureau of Mines to investigate the dangers of tetraethyl lead, but demanded that no publicity regarding the research be provided to the press. And the Ethyl Gasoline Corporation, formed by General Motors and Standard Oil in 1924, also required that the federal agency’s work be submitted to Ethyl prior to publication for “comment, criticism, and approval.”
From Florida, Midgley recommended that General Motors pursue the leaded gasoline business aggressively as, by his calculations, the company had much to gain financially from the move. “Midgley barely scratched the surface of the wealth to come,” wrote Kitman, noting the profits from GM’s patents on the product.
In 1924, five workers died and dozens more were lead poisoned in a disaster at Standard Oil Company’s experimental laboratories in New Jersey. But Ethyl Corporation’s manufacturers continued to claim the additive was safe. And the Bureau of Mines issued its report on the heels of those deaths in 1924 and exonerated tetraethyl lead, finding the danger of lead accumulation on streets via car exhaust to be remote.
In the 1920s, two of the most adamant voices on the dangers of leaded gasoline were Yandell Henderson, a Yale University physiology professor, and Alice Hamilton, a Harvard University professor of industrial medicine.
Henderson warned the federal government that lead exhaust from cars would cause widespread chronic lead poisoning in urban centers, and criticized the Bureau of Mines report as shoddy.
Henderson said that “conditions would grow worse so gradually and the development of lead poisoning will come on so insidiously … that leaded gasoline will be in nearly universal use and large numbers of cars will have been sold … before the public and the government awaken to the situation,” according to Markowitz and Rosner.
Hamilton, a pioneer in industrial medicine and occupational health hazards, became convinced that the danger workers faced was from breathing lead-contaminated air.
At a Washington, D.C. conference in 1925, the U.S. surgeon general convened experts to discuss the dangers of leaded gasoline. Henderson and Hamilton’s warnings about lead’s dangers and the need for data and government intervention were prescient, but not everyone agreed.
Ethyl Gasoline Corporation representative, Frank A. Howard, objected on the grounds that the GM Corporation and Standard Oil Co. of New Jersey had invested years of research to produce “this apparent gift of God.”
“Because some animals die and some do not die in some experiments, shall we give this thing up entirely?” he asked the conference. The industry wanted more definitive proof of lead’s threat to human health.
“Because some animals die and some do not die in some experiments, shall we give this thing up entirely?”
Henderson pointed out that three years before the conference, the same corporations approached him and other scientists to investigate lead. But the Ethyl Gasoline Corporation “dropped the matter,” said Henderson, and did not proceed after the scientists emphasized the investigation should focus on public safety.
That conference led Ethyl Corporation to suspend production and distribution of leaded gasoline until the public health concerns were addressed. A blue ribbon committee organized to investigate the matter ultimately found that “there are at present no good grounds for prohibiting the use of ethyl gasoline… provided that its distribution and use are controlled by proper regulations.”
The committee warned the surgeon general that if leaded gasoline use became more widespread those conditions could render it more hazardous, leading to chronic diseases that were of a “less obvious character.” The committee strongly urged that Congress fund further investigations, but those suggestions were never carried out, wrote Markowitz and Rosner.
By the late 1920s, the role of the federal government transitioned from skeptical oversight to commercial support of Ethyl. It was then that the surgeon general began writing introduction letters for Ethyl Corporation officials to health ministers of foreign nations and “actively promoted Ethyl-brand leaded gasoline at European scientific conferences,” according to William J. Kovarik, a communications professor at Radford University.
The U.S. government’s failure to scrutinize the long-term effects of leaded gasoline would directly impact the health of millions of American children over the next century.
The ‘torturous path from science to policy’
Environmentalist and microbiologist René Dubos once observed that when it came to childhood lead poisoning: “The problem is so well-defined, so neatly packaged, with both causes and cures known, that if we don’t eliminate this social crime, our society deserves all the disasters that have been forecast for it.”
In 1943, a groundbreaking study on the effects of lead poisoning on mental development showed that the assumptions at the time — that a child was lead poisoned only if she or he showed certain clinical signs and symptoms — were wrong, wrote Harvard University Professor David Bellinger and his co-author Andrew Bellinger in their report “Childhood lead poisoning: the torturous path from science to policy.”
“The problem is so well-defined, so neatly packaged, with both causes and cures known, that if we don’t eliminate this social crime, our society deserves all the disasters that have been forecast for it.”
But research and scientific advancements lagged behind the industrial production of lead products such as leaded gasoline, so lead pollution grew at a faster rate than the ability of researchers to diagnose lead’s effects, said soil lead contamination expert Howard Mielke of Tulane University’s School of Medicine.
“Long after the industry had already put huge amounts of [lead] material into the environment, we didn’t have a way of measuring it in the blood,” said Mielke.
Throughout the 1960s, the effects of lead were still being measured through what epidemiologist Philip Landrigan described as an “either/or phenomenon”: The child was either lead poisoned or well, based on whether she or he showed clinical signs or visible symptoms. At that time, the federal government defined elevated pediatric lead levels as concentrations 60 micrograms per deciliter (mcg/dL) or higher.
Scientists made major advancements in the 1970s and 1980s on techniques that measured lead in the blood at lower levels, allowing researchers to begin to understand the health issues connected to different exposure levels, said Mielke.
And as researchers began to show that lead could affect children’s behaviors and reduce intelligence—at lower exposure levels that didn’t produce obvious symptoms—the federal government began lowering the threshold for what was considered an elevated lead level for children.
“Long after the industry had already put huge amounts of [lead] material into the environment, we didn’t have a way of measuring it in the blood.”
The federal government dropped the level from 40 mcg/dL in 1971, to 30 mcg/dL in 1978, ultimately reducing the level to 5 mcg/dL in 2012, a level at which the Centers for Disease Control and Prevention [CDC] recommends public health intervention for children.
Today, the CDC states that that no level of lead in children is safe, and later this year may reduce the reference level further to 3.5 mcg/dL based on a recommendation by the Board of Scientific Counselors that advises the CDC’s National Center for Environmental Health and the Agency for Toxic Substances and Disease Registry. That recommendation is currently under review by the CDC, according to an agency spokeswoman.
The phase-down in the use of leaded gasoline starting in the 1970s also played a role in helping researchers study children who had been exposed to smaller amounts of lead in the environment, said Mielke. Lead emitted as an aerosol into the environment accumulates in soils and does not biodegrade, so it can remain in the soil for hundreds of years and thus also contributes to chronic lead exposure in children, according to research by Mielke and his colleagues.
“So we’ve done a massive experiment on the human population and we are seeing some of the results in our healthcare system in different ways,” said Mielke.
In 2000, when Landrigan wrote his public health commentary, epidemiologist Bruce Lanphear and his colleagues had just published research on lead’s toxic effects at levels lower than 5 mcg/dL.
But even with mounting scientific evidence documenting the effects of low levels of lead exposure, the Bellingers point to other factors that contributed to the lack of public action on childhood lead poisoning in the last half of the 20th century. Health providers focused just on patient behavior rather than examining broader community issues that may have contributed to childhood lead poisoning.
As a result, “the responsibility for lead poisoning was placed on the victim and his or her family rather than on the dilapidated housing that caused it or on the institutions, policies, and regulations that permitted such lead hazards to exist,” wrote the Bellingers.
“In effect, children were treated as sentinels, used to identify the presence of lead hazards in much the same way that miners used canaries,” wrote the Bellingers.
Researchers battle it out in the court of public opinion
The lead industry’s aggressive marketing campaign, starting in the 1920s and lasting through the 1960s, played a major role in casting doubt about the dangers of lead. By funding research by its own scientists and physicians, such as Robert A. Kehoe, the Ethyl Corporation effectively shut down arguments about the risks of polluting the air with leaded gasoline emissions.
Kehoe claimed that since lead was found in the natural environment, introducing more lead into the environment would pose no danger to people. He also asserted that his research had “conclusively” shown that lead poisoning did not occur below 80 micrograms per deciliter, “even in infants and children.”
In 1965, at a conference sponsored by the U.S. Public Health Service, Kehoe made the argument that humans could excrete lead as rapidly as they inhaled or ingested it, according to the Lead Wars: The Politics of Science and the Fate of America’s Children by historians Gerald Markowitz and David Rosner. But evidence-backed science on lead poisoning was growing, and speakers at the conference “dismantled” Kehoe’s assertions.
Earlier that year, Clair C. Patterson, a California Institute of Technology geochemist who had pioneered techniques to measure lead levels, published a paper that challenged the notion that high levels of lead were naturally found in the environment, and showed how massive amounts of industrial lead had contributed to widespread contamination of the environment.
That fall, the American Petroleum Institute responded in the Wall Street Journal to Patterson by concluding that his findings had “no real bearing on the public health aspects of lead.”
Ultimately, policy makers implemented regulations on lead starting in the early 1970s as public awareness and outrage over environmental pollution increased across the country. The EPA’s first administrator, William D. Ruckelshaus, credits this public support and demand for helping to establish the Environmental Protection Agency. In an EPA oral history interview, Ruckelshaus explains how President Richard Nixon was motivated to create the agency by, more than anything, public outrage over environmental issues.
“Public opinion remains absolutely essential for anything to be done on behalf of the environment. Absent that, nothing will happen because the forces of the economy and the impact on people’s livelihood are so much more automatic and endemic,” said Ruckelshaus in that interview.
In 1973, the EPA issued a study confirming that lead from automobile exhaust posed a direct threat to public health, and followed those conclusions by issuing regulations that called for a five-year reduction of lead in gasoline, from 2 grams to 0.5 gram per gallon, starting in 1975. Public pressure, the environmental movement, and a lawsuit filed by the Natural Resources Defense Council motivated the EPA to act.
The lead industry fought the regulations, with a senior researcher for the Ethyl Corporation arguing that most studies had shown that automobile lead emissions had no impact on human health, according to Lead Wars. The Ethyl Corporation, DuPont, and others then sued the EPA to try to halt the agency from regulating lead in gasoline.
The U.S. Court of Appeals of the District of Columbia ruled in favor of the EPA in 1976, but the lawsuit led the EPA to proceed more cautiously, according to Markowitz and Rosner.
So at the turn of the 21st century, with mounting scientific evidence showing that no level of lead was safe for children, similar battles began to play out in California as the industries responsible for putting lead in the environment began to challenge the state government.
At the heart of the matter was the question of who was responsible for paying the costs to identify and treat the children who have been chronically exposed to lead in California’s environment: a predicament that Yandell Henderson foresaw in the 1920s when he said the public’s health would be threatened from pollution due to the lead exhaust from cars.
California ‘missing a lot of children’ with lead exposure
Identifying the extent of California’s childhood lead poisoning problem was one of the first responsibilities of the state’s Department of Health Services [now known as the California Department of Public Health].
In 1986, when California passed its first Childhood Lead Poisoning Prevention Act, the state declared childhood lead exposure as the “most significant childhood environmental health problem in the state.”
Legislators established the Childhood Lead Poisoning Prevention Program within the Department of Health Services to determine how widespread the problem was, and directed the agency to “to take steps necessary to reduce the incidence of childhood lead exposure in California.”
Four years later, however, the agency landed in legal trouble for not following through on this mission.
“Public opinion remains absolutely essential for anything to be done on behalf of the environment.”
In 1990, the NAACP Legal Defense and Educational Fund and other organizations filed a federal civil rights lawsuit against Department of Health Services’s Child Health and Disability Prevention [CHDP] program on behalf of two Oakland children who were denied blood lead level assessments by the program.
The case was settled the following year with the state agreeing to take action on several key fronts: to perform blood-lead testing on all 1 and 2-year-olds that received CHDP services, and to collect all blood lead tests analyzed by laboratories of children in the program as well as all other children up to age 15.
The program also had to focus on “reducing and eliminating sources of lead to prevent further exposure,” a goal that California legislators incorporated that same year into the 1991 Childhood Lead Poisoning Prevention Act, which expanded the agency’s responsibilities to evaluate all children for lead poisoning risk and test those at risk.
The law also established a fund to support the state program by imposing fees on industries that had significantly contributed to or continue to contribute to, environmental lead contamination.
But in 1999, nearly a decade after the NAACP lawsuit was filed, the California State Auditor found that the Department of Health Services hadn’t met two of its key goals: ensuring that all at-risk children were tested, and using those test results to determine how widespread lead poisoning was throughout the state.
The agency had also fallen short on a number of other basic requirements: evaluating all children for lead exposure; testing all children enrolled in the state’s healthcare program for low income families (less than 25 percent of these children were tested); ensuring that all laboratories reported blood lead test results to the state; and case-managing children who are lead poisoned.
Eight years earlier, the CDC had published recommendations calling for virtually all 1 and 2-year-old children to receive blood lead testing “unless the states had evidence that lead poisoning was not a problem in the child’s community.”
“Children were treated as sentinels, used to identify the presence of lead hazards in much the same way that miners used canaries.”
And even though state law required DHS to adopt regulations that would set a standard requiring providers to evaluate all children to determine their risk for lead poisoning, the agency told the state auditor that the department did not follow this guideline due to the national and local controversy surrounding the CDC recommendation.
“As early as 1994, national data suggested that screening all children was no longer necessary,” DHS wrote in its response to the state audit. “These national surveys indicated that the prevalence of lead poisoning among children six years or younger dropped in half between 1988 and 1993, and lead poisoning increasingly was concentrated in low-income minority children residing in old, deteriorated urban housing stock.”
A year after the California State Auditor issued its critical report of California’s Childhood Lead Poisoning Prevention Branch, an environmental research organization released its own report detailing the findings from a nearly year-long investigation that revealed the state had failed to identify or provide care for an estimated 200,000 lead poisoned young children from 1992 to 1998.
The report determined that more than 43,000 young children (ages 1 to 5) lived in critical hot spots for lead, and another 239,000 children lived in very high risk areas throughout California.
Based on existing state data on the number of children tested for lead poisoning, the nonprofit concluded that statewide no more than one in five children was tested for lead poisoning. At the time, the study also estimated that no California county had identified more than 13 percent of the estimated number of lead poisoned children.
The report also found that the failure to require laboratories to report all blood lead levels had prevented the state from accurately assessing the dangers of childhood lead poisoning.
Orange County’s history of elevated childhood blood lead levels
Resistance from California’s pediatric providers made it difficult for the Childhood Lead Poisoning Prevention Branch to rapidly develop a statewide screening standard in the 1990s.
Indeed, in Orange County, a report examining the appropriateness of a universal pediatric blood lead screening policy revealed how complicated the controversy was during that decade.
In 1993, one of the county’s top public health officials, George A. Gellert, co-authored a report showing that 7.25 percent of the children in Orange County had levels at or higher than 10 mcg/dL.
The report downplayed the prevalence, which is the percentage of the population affected by a disease. “A 7.25 percent prevalence of most other preventable childhood conditions would be considered high,” the report stated. At the time, the CDC recommended no action other than retesting for children with those blood lead levels.
“A 7.25 percent prevalence of most other preventable childhood conditions would be considered high.”
Gellert et al. dismissed pediatric lead poisoning among Orange County children as “not a major public health problem.” Their reasons: the county’s small percentage of severely lead-poisoned children and its low percentage of pre-1950 housing, which is more likely to have lead-tainted paint. Orange County ranked last on the list of California counties by percentage of pre-1950s housing, they noted.
But as the research of soil lead experts such as Howard Mielke have shown, leaded gasoline emission particles that have settled in the soil remain a threat to children. And Gellert and his co-authors gave a slight nod to soil that signaled a sense of how widespread the soil lead problem was.
They noted that the costs of abatement for lead paint and, “more importantly, in community soil may be enormous,” and recommended that public health policymakers offer strategies and funds to remediate the risks with improved detection and surveillance systems.
Court battles delay progress in addressing childhood lead poisoning
In 1997, after the CDC changed course on its recommendation that all children be screened for lead poisoning, the agency instead advised that state officials target at-risk children.
However, pinpointing which children were most at risk required blood lead test data. And as the California state auditor found in 1999, the Department of Health Services lacked this data because it had not collected blood test results for all children up to 15 years, nor had it adopted regulations requiring labs to report all blood test results to the state.
Because of this, the agency had not been able to report accurately on “where and to what extent” childhood lead poisoning exists in the state, the auditor concluded. Thus, the agency continued to find itself battling pediatricians and other health care providers who were unconvinced that childhood lead poisoning was a problem. The auditor blamed insufficient data.
In its written response to the audit, the health agency stated that the lack of regulations hindered the collection of blood lead data, but so did the lack of computer software to report and collect the data from labs, which would have required “a significant resource commitment.”
(The blood data collection issue was addressed in 2002 when California legislators approved a bill mandating that laboratories that conduct blood lead analysis report all results to the Department of Health Services.)
Other obstacles the agency cited include the recession facing California in the early 1990s, and funding cuts after the Sinclair Paint Company legally challenged the fees that the California Board of Equalization levied against industries responsible for polluting the state’s environment with lead.
The paint company lawsuit severely hampered the work of the agency, which noted in the state audit that the Childhood Lead Poisoning Prevention Branch (CLPP) imposed a hiring freeze, shifted its resources to prioritize county-level care for lead poisoned children, and reduced resources for state-level programming.
These budget reductions in turn prevented the agency from developing the regulations required by law, the health agency said.
The Sinclair Paint lawsuit wouldn’t be the last. Over the course of the next decade, the petroleum industry would similarly resist paying these fees, which in turn caused further delays in funding.
This included a lawsuit in which Shell Oil alleged that the state unfairly levied fees on the petroleum industry for lead contamination in California. In the 2008 California Superior Court decision, the state found that 85 percent of California’s lead contamination came from the petroleum industry and about 14 percent from the paint industry.
Judge Judy Holzer Hersher also cited evidence showing that dust and soil contaminated by leaded gasoline is the “most significant environmental lead contaminant in the state of California,” and that lead from gasoline is “the dominant source of lead exposure to children in California.”
Concerns with the industry litigation were raised earlier that decade during a 2004 California state senate hearing in Sacramento on childhood lead poisoning that was organized by Sen. Deborah Ortiz, (D-Sacramento) and Sen. Jackie Speier, (D-San Mateo).
During the hearing, Childhood Lead Poisoning Prevention Branch chief Valerie Charleton testified that the Western States Petroleum Association had also failed to pay their fees in full, an estimated $6 to $7 million that year. The industry push-back concerned Ortiz.
“I think it’s the tip of the iceberg on this one,” said Ortiz during the hearing. “It just is appalling. But maybe it’s just because they’re poor children in poor communities and there isn’t a lot of political strength and a voice to who is harmed here.”
“It just is appalling. But maybe it’s just because they’re poor children in poor communities and there isn’t a lot of political strength and a voice to who is harmed here.”
The senators also honed in on a problem with the way the state’s Childhood Lead Poisoning Prevention Branch was measuring the scope of lead exposure across the state.
The branch’s officials informed the senators that the number of lead poisoned children had decreased by about half in a little less than a decade even as the state increased the number of children tested. But Speier pointed out that these results only indicated a decrease among the fraction of children who had been tested: Ortiz told public health officials that testing programs were likely missing preschool-aged children as well as uninsured children.
“So, part of my difficulty is we’re missing a lot of children. Despite that one snapshot that we’re beginning to be able to measure, it comes nowhere near where the risk is to this community. It just is really sad,” Ortiz stated, according to a transcript of the hearing. “I think we need to understand, by the time a child is three, if they’ve been exposed from whatever sources, this is permanent; pretty much irreversible damage.”
California’s screening rate has fluctuated over the years. The state’s peak year was in 2010 when 20.7 percent of California’s young children were tested, a slightly higher rate than the national screening level at the time of 17.7 percent, according to a CDC dataset of children under six years who were tested across the country from 1997 to 2014. Today, experts say the national average is about 25 percent.
Failing to protect California’s children from further lead exposure
State officials have known for years that finding lead sources is crucial to helping prevent childhood lead poisoning. During the 2004 California Senate hearing on lead poisoning, the state’s public health officer Richard Jackson cited home investigations as key to addressing childhood lead poisoning cases.
The hearing, however, left senators with more questions than answers.
“I’m alarmed that with as much as we know about the threats posed by lead poisoning, we still do not have a full grasp of the problem and about the sources of the lead,” said Sen. Jackie Speier during the hearing.
“I’m alarmed that with as much as we know about the threats posed by lead poisoning, we still do not have a full grasp of the problem and about the sources of the lead.”
Speier went on to represent California’s 14th congressional district and has continued to address lead issues at both the local and federal level.
“It’s pretty clear the problem is not fixed,” said Speier in an interview, noting the bill introduced in March by California Assemblyman Bill Quirk (D-Hayward) that would require blood lead testing of all California children.
Last fall, Speier introduced the “No Lead in School Water Act,” a federal bill to help schools test for and remove lead from their water supply systems by providing funding and by setting standards for state-based lead testing and remediation.
The bill did not move forward in Congress, but Speier plans to reintroduce the legislation again this year.
“We have authorized hundreds of millions of dollars for Flint,” said Speier. “But as we’ve come to find out, Flint is just one of many areas [affected].”
“As we’ve come to find out, Flint is just one of many areas [affected].”
In 1984, during the U.S. Senate committee hearing on reducing lead in gasoline, then-Sen. David Durenberger (R-MN) made a forceful argument that it was time for action.
Durenberger cited “startling new evidence, which indicates that lead, even at low levels is far more harmful to humans than previously thought,” and urged Congress to phase out gasoline sooner than its projected 1988 target.
He used the words of one of America’s founding fathers, Benjamin Franklin, to remind his fellow senators that the dangers of lead have been known to man for centuries.
In a letter, written in 1786, Franklin warned a friend about lead’s effects and described the Massachusetts legislature’s decision to outlaw leaden still-heads in rum distilleries when he was a boy. Durenberger told the committee that he believed this to be the first legislation banning lead in the United States.
Franklin outlined the many instances of lead poisoning that he had encountered around the world, ranging from London print shop workers poisoned by lead type to Parisian plumbers and painters hospitalized by the toxin.
“This, my dear friend, is all I can at present recollect on the subject,” Franklin wrote at the end of his letter. “You will see by it that the opinion of this mischievous effect from lead is at least above 60 years old; and you will observe with concern how long a useful truth may be known and exist before it is generally received and practiced on.”
This project was made possible through the generous support of a community health reporting fellowship from the International Center for Journalists.