The History of Leaded Gasoline: Profit Over Public Health

The Prioritization of Profit Over Safety

Leaded gasoline was introduced to the market in 1923, despite tetraethyl lead (TEL) being a known toxic compound. The decision to use TEL over safer alternatives like ethanol was driven by corporate interests: ethanol could not be patented, meaning General Motors and other oil companies could not control its production or secure exclusive profits.

The Technical Solution to "Knocking"

In 1921, General Motors engineer Thomas Midgley Jr. discovered that tetraethyl lead (TEL) effectively reduced "knocking" in internal combustion engines by raising the fuel's combustibility, or octane rating. While Midgley tested various substances—including melted butter and aluminum chloride—ethanol was the most effective anti-knock agent. However, GM and oil companies like Du Pont rejected ethanol because it lacked patentability and threatened their control over the engine's fuel supply.

Known Toxicity and Early Warnings

TEL was a known poison long before its widespread adoption. A Du Pont executive in 1922 described it as a "colorless liquid of sweetish odor, very poisonous if absorbed through the skin, resulting in lead poisoning almost immediately."

Despite these warnings, the first tank of leaded gasoline was sold in February 1923. The rollout was marked by immediate danger: Thomas Midgley Jr. himself suffered severe lead poisoning and was bedridden during the launch. Furthermore, five workers died from TEL exposure at a Standard Oil Refinery in New Jersey shortly after the introduction.

The Role of Corporate-Funded Research

The adoption of leaded gasoline was persisted through the control of research. For decades, the primary advocate for leaded gasoline was Robert A. Kehoe, working for GM, who was the chief researcher on lead. This created a paradigm where the lead industry set the assumptions about safety thresholds and the belief that lead was natural to the human body.

"Two beliefs became entrenched: 1. that lead is natural to the human body, and 2. that a poisoning threshold for lead existed."

It was not until Clair Patterson, while measuring the age of the earth, stumbled upon the lead contamination of the environment, that these corporate-funded paradigms were challenged. Even after Patterson's research was published in 1965, it took until the mid-1970s for the EPA to phase out leaded gasoline through legal struggles with gasoline makers.

Long-Term Public Health Consequences

The use of leaded gasoline has had devastating, long-term effects on human health, particularly on children. Lead exposure is linked to lower IQ, hyperactivity, behavioral problems, and learning disabilities.

Research indicates that lead exposure in children is strongly linked to violent crime and cognitive loss. One study cited in the PNAS journal suggests that the average lead-linked loss in cognitive ability was 2.6 IQ points per person as of 2015. Much of this lead remains in the environment today, continuing to pose a risk to future generations.

Global Phase-Out and Remaining Risks

While leaded gasoline is now banned for road vehicles globally as of 2021, some risks remain. Some aviation fuel for propeller aircraft continues to use lead, continuing to contaminate land around airports worldwide.