By Bridget Mackie

When Lead Covered the Earth

By Bridget Mackie

Like many children born in the early 2000s, I grew up in a world with relatively little lead. My toys were lead-free, and the paint that chipped off of my walls was no more harmful than dust on the floor. Most importantly, I lived in a world without leaded gasoline. The same cannot be said for my parents’ generation, who grew up in a perpetual snowfall of lead. It plumed from the exhaust of cars, accumulated in the atmosphere, and fell, dusting the ground. There, it settled and remained for decades of children to play in.

Leaded gasoline has its origin in the early 1900s. As cars grew in popularity, desire for more powerful and efficient cars grew as well. However, as cars got more powerful, a strange phenomenon emerged; the engines began to make a loud knocking sound. The cause of “engine knock” eluded scientists for years. That is until Thomas Midgley hit the scene. Midgley, an American mechanical and chemical engineer, seemed to have had a mind for inventing from a young age. It is this mind, and its products, that came to define his life and legacy.

By 1916, Midgley was an engineer working at General Motors when he stumbled upon the problem of engine knocking. Contemporaries blamed the problem on the battery ignition, but Midgley hypothesized something different. Engine knocking, he discovered, was a result of the compressed fuel and air within the engine exploding. If Midgley could solve this problem, engines could run smoother and more efficiently than ever before. By 1920, researchers were developing fuel additives to reduce engine knock. There were especially promising formulas using combinations of ethanol and petroleum, and Midgley himself filed a patent application for one such formula. Ultimately, these developments would be overshadowed by a different fuel additive.

Midgley began his search for this new additive by taking out his periodic table and testing all sorts of elements. Eventually, he had a list of several elements that were found to raise a fuel’s octane rating, a measure of a fuel’s resistance to engine knock. However, all these elements were expensive or scarce and wouldn’t be economically practical. On a whim, Midgley tried tetraethyl lead (TEL), a form of lead that dissolved easily in gasoline. It turned out that TEL was effective, cheap, and abundant, so it became the winning solution. Thus, inspired by Midgley’s findings, the Ethyl Gasoline Corporation was born, whose name conveniently dropped all mentions of lead. At the time lead had been a known toxin for centuries. In fact, ancient Romans had observed the ill effects on laborers working with the element. It is not surprising, then, that the public was concerned when reports surfaced of workers suffering psychosis —and in some cases dying—in factories producing leaded gasoline.

These factories became known as “houses of butterflies’’ because of a common hallucination suffered by workers. One factory in New Jersey was reportedly full of butterflies. They would land on the workers’ jackets tenderly, almost as if they weren’t there at all. Then they would brush them off and watch as they disintegrated into the air. These hallucinations of butterflies often preceded a bleaker fate. In the early 1920s, at least fifteen workers at this New Jersey plant died of acute lead poisoning, while dozens of others suffered permanent brain damage. Reports of these occurrences left the Ethyl Gasoline Corporation with a PR problem. In an effort to combat the bad press, the Ethyl Corporation—along with several other companies, including Gen-

eral Motors—launched a campaign to convince the public that their toxic gasoline was safe. The ‘scientific’ basis of the campaign relied on studies by scientists commissioned by the lead industry. Uncoincidentally, these studies’ results were marred by poor technique. Many falsely concluded that lead exists naturally in the human body and is therefore safe under certain levels.

While these ‘scientific’ studies satisfied government officials, Midgley himself went on a tour of the United States in order to prove the supposed safety of leaded gas to the public. His demonstrations included washing his hands with leaded gasoline and breathing in the fumes from a car running on leaded gasoline. Not long after this campaign, Midgley took a leave of absence to the sunshine of Florida because he had been diagnosed with acute lead poisoning. Unfortunately, the workers in TEL factories couldn’t take a vacation to clear their lungs.

This campaign concluded in a public health conference conducted in August 1925 by the Surgeon General of the United States. The conference included many scientists from the lead industry who discussed their flawed studies. Ultimately, the main argument of the Ethyl Gasoline Corporation became an economic one. What were a few worker deaths in the face of the vast economic and industrial gains that will result from this gasoline? This argument was perhaps the most convincing to the public and government. Soon, leaded gasoline became the standard in automobiles. The problem was that leaded gasoline did not just affect a few factory workers. As public health advocate Dr. Alice Hamilton pointed out at that same conference, “lead is a slow and cumulative poison, […] it does not usually produce striking symptoms that are easily recognized.” Hamilton, along with several other public health advocates, was among the first people to raise the question of leaded gasoline’s effects on public health.

Despite Hamilton’s initial concerns about leaded gasoline, investigation of low level lead exposures did not begin until much later. It began with an unexpected discovery by a young geochemist named Clair Patterson in the late 1940s. Patterson originally was working with lead in a very different context than Midgley. Early in his research using the amount of lead in meteors to estimate the age of the Earth, he encountered a strange, unexpected problem. The meteors had a disproportionate amount of lead in them that indicated impossible ages for the rocks. He reasoned that there had to be another source of lead that was contaminating his samples. In his search for the source, he realized that lead was everywhere—all over the walls of his laboratory, on his lab coat, even on his hair and skin. It took seven years for Patterson to create an uncontaminated lab and finish his work dating the age of the earth, but he remained vexed at the original source of the persistent lead contamination.

This question led Patterson to a lifetime of research on the prevalence of lead in the atmosphere. Patterson’s early research took him to the bottom of the ocean where he measured the amount of lead in layers of sediment. He found that newer sediment layers had significantly higher lead levels than older layers. In 1963, these findings were the first to be published about lead in the environment. Throughout the 1960s, Patterson continued to study lead contamination in the atmosphere, using Antarctic ice cores and ancient Peruvian human remains to compare atmospheric lead concentration throughout history. Time and again Patterson proved that atmospheric lead levels were not naturally high but rather were directly related to human industrialization. In one of his articles, Patterson argued that, “the average resident of the United States is being subjected to severe chronic lead insult.” This conclusion was not well received by many in the scientific community, and he was especially attacked by the lead industry. He was branded as a “crackpot” by the Ethyl Corporation, who sought to undermine his scientific credibility. Eventually, though, Patterson’s research was corroborated by other scientists concerned about the effects of lead at low levels of exposure.

The most notable of these scientists was Dr. Herbert Needleman. Needleman’s interest in lead primarily grew out of a concern for the health of children. In the mid1960s, Needleman was working as a pediatric psychiatry resident at the St. Christopher’s Hospital for Children in Philadelphia. He was disappointed in the training he was receiving and began to question if environmental factors,

like lead, were causing learning disabilities in children. Pursuing this question, Needleman conducted dozens of studies analyzing the behavioral effects of lead on children, particularly related to attention, intelligence, and aggression. In 1979, he published a study that found that higher levels of lead were linked to lower intelligence quotients (IQs)— about 4 points lower on average. The study was met with significant pushback from the lead industry, who sought to discredit Needleman’s work. This culminated in a scientific misconduct investigation which dragged on for years, but eventually ruled in Needleman’s favor. Despite this challenge, the study overcame the pushback and changed the way the public and the scientific community viewed lead poisoning. Even if lead exposure didn’t cause severe illness in a child, it could still affect their quality of life. Yet, by the time Needleman published these results, leaded gasoline was already beginning to be phased out of cars.

While this was partly because of growing concern about lead’s effects on public health, it was predominantly because of new government regulations related to other forms of air pollution. The passage of the Clean Air Act of 1963 and later amendments required the automobile industry to find ways to reduce pollutants. The catalytic converter was invented to reduce air pollutants from car exhaust, but leaded gasoline destroyed these converters. Although the automotive industry resisted the catalytic converter initially, the EPA mandated that all new cars from 1975 onward needed to have a catalytic converter. This meant that unleaded gasoline would need to be more widely available, thus beginning the decline of leaded gasoline.

Though the 1970s saw significant reduction in leaded gasoline, the 1980s brought the Reagan administration and its efforts to ease up on big business. In 1985, EPA economist Joel Schwartz investigated the social and economic costs of leaded gasoline regulation. It would cost 100 million dollars to regulate leaded gasoline, but the social cost as a result of lower paying jobs and increased health costs weighed in at about 1 billion dollars. Without an economic leg to stand on, the leaded gasoline industry began to crumble. Finally, in January of 1996, leaded gasoline in automobiles was officially phased out in the US. The effects of this phase-out were dramatic. In the late 1970s, the federal government set up a National Health and Nutrition Examination Survey (NHANES) which measured the blood lead levels of around 20,000 people, including children. The survey found that nearly 99.8 percent of children had blood lead levels that would be considered elevated by today’s standards. With the subsequent phaseout of leaded gasoline, average blood lead levels dropped by 95 percent between 1977 and 1994. The most recent NHANES study, conducted from 2007 to 2010, found that less than 3 percent of children had elevated blood lead levels.

Thomas Midgley died in 1944, long before Patterson and Needleman began conducting their research. He contracted polio, which limited his mobility. In response to his condition, he invented a contraption to help him get out of bed. One day, though, something went horribly wrong, and he was strangled in the elaborate mess of pulleys and cables. In a way, we have all been caught up in the mess of Midgley’s creation. However, to blame only Midgley would be to ignore the dozens of government officials, scientists, and physicians, who conducted poor research and ignored the voices of those who stood up for public health. Leaded gasoline poisoned generations of children, and its legacy continues today. Atmospheric lead levels remain higher than natural background levels despite the decrease since the phase out of leaded gasoline in cars. Leaded gasoline continues to be used widely in aviation gas and is the largest source of atmospheric lead pollution, comprising about 50% of lead emissions. Current evidence suggests that children who live in areas near major airports tend to have higher blood lead levels than the national average.

It is impossible to know how our inventions will define us. Midgley could not have known that part of his legacy would be defined by the devastating effect of lead on children’s brains. The story of leaded gasoline shows us that public health is vulnerable to economic interests. Midgley was not the only player in this story. Scientists like Patterson or Needleman show us that science is not completely corrupted by economic interests. The pendulum ultimately swung in the direction of public health, but as pendulums are never static, it is possible for it to swing the other way. Back and forth this pendulum swings. Someday, we might reach an objective truth that favors the health of the people, but that will only be achieved by valuing people’s well-being over economic gain. H

Art by Samantha Clancy