Lead is a well-known poison. Its harmful effects have been known for 2,000 years. Dioscorides wrote that “Lead makes the mind give way.” Yet 100 years ago, car manufacturers and oil companies started a mass lead poisoning.
Researchers at General Motors found that by adding a lead compound, tetraethyl lead (TEL), several problems with internal combustion engines could be overcome. TEL is cheap, and large profits beckoned for oil and auto companies — never mind the health costs.
Since the 1920s, cars, trucks, and planes have spewed lead into the air, water and soil, and on into humans.
Knock & TEL
Internal combustion engines rely on a spark igniting a mix of gasoline and air in the engine’s cylinder at the right time, when the piston is at the ideal position, to give maximum power. If the mixture detonates at the wrong time, it can cause “knocking” that damages, or even destroys, the engine.
Adding TEL raises the temperature at which the gasoline/air mixture detonates and so reduces knocking and the risk of engine damage. All gasolines have an octane rating; the higher the octane, the higher the temperature at which the fuel mixture will detonate. The octane number indicates how likely the fuel is to burn in the desired, controlled way rather than exploding and causing damage. Higher octane fuels can be used in higher pressure engines, which boosts power.
TEL, first synthesized in 1854, was not an important manufactured chemical before its use in engines. Dupont, which made TEL, worked with General Motors to develop TEL as an anti-knocking agent. Its ability to stop knocking was established in December 1921. Standard Oil of New Jersey (now Exxon) and General Motors established the Ethyl Gasoline Corporation in 1923 to make TEL to add to gasoline. Initially, Dupont, with experience of making TEL, ran the manufacturing.
Profitable Poison
Even before its use in gasoline, it was known that TEL is toxic. Its trade name, Ethyl, was chosen to hide its lead content. Within months of starting manufacture, of the 49 workers in the building making TEL, 35 were in hospital suffering from severe lead poisoning, hallucinations, and insanity. Five died. The workers in the plant called it “loony gas” because of its damage to mental capabilities.
After investigation by public health staff in New York, the state of New Jersey and cities of New York and Philadelphia banned sales of TEL. Ethyl Corporation suspended production but lobbied US President Coolidge to investigate. The US Surgeon General set up a review panel, made up of industry representatives, including Midgley, the researcher who developed TEL as an anti-knock agent, but not the public health officers who had researched TEL’s dangerous, even fatal, effects.
As an aside, Midgley later went on to develop the first commercial chlorofluorocarbon (CFC) that damages the earth’s ozone layer in the upper atmosphere, which shields earth from harmful ultraviolet light. It has been claimed that he contributed more to damaging the environment than any other person
The review panel’s report, released in 1926, stated that TEL in gasoline was “no danger;” there was “no reason to prohibit the sale of leaded gasoline.” All they recommended was improved protection for the workers making TEL. This ended the bans imposed in New York, Philadelphia and New Jersey.
New York’s chief medical examiner, Charles Norris, was not convinced and directed that the lead content of dirt on the city’s streets be recorded. In 10 years between 1924 and 1934 lead levels increased 50 percent.
There were many warnings from chemists and public health researchers of the dangers of TEL. Why, with all the obvious health dangers, did TEL get used? Other chemicals added to gasoline can also stop knocking. A common answer is to add ethyl alcohol. In fact, Midgley had investigated it. However, ethyl alcohol cannot be patented, TEL can. For the car makers it solved a major problem of engine knock and allowed for more powerful vehicles.
At the beginning of the 20th century, electric cars were popular, selling more in the US than gasoline vehicles, albeit in small numbers. Compared to gasoline cars, they were quiet, less smelly and polluting, easy to start and more reliable. Their use however was limited to cities as the batteries had a small range. With the development of electric starter motors, instead of hand cranking, knocking solved and cheaper gasoline, electric vehicles were largely forgotten for decades. Solving knocking was one step in the path to automobiles dominating transport; however, there were much safer ways to deal with the problem.
The Passing of time
Research constantly pointed to the damage that lead caused. In 1909, France, Belgium, and Austria banned white lead-based interior paint, and in 1922 the League of Nations banned lead-based paint.
As evidence grew showing the harm of the lead, the safety guidance was modified. In 1920s the “safe” threshold for lead in blood was set at 80 micrograms of lead per decilitre (a tenth of a litre) of blood. Further research found that much lower levels of lead, while not causing fatal poisoning, would hinder childhood mental development. Now it is known that levels below 10 micrograms can still cause harm cognitive development — there is probably no safe level. Young children are especially vulnerable.
Leaded gasoline also included chlorinated additives, which when burnt produced dioxins, another family of poisons, even at very low levels.
After years of pressure and mounting evidence, the tide began to turn. Unleaded gasoline started being produced in the 1970s and vehicle makers found ways to avoid knocking without using leaded gasoline. In 1986 Japan was the first country to phase out leaded gasoline. The US ruled that the amount of lead in gasoline had to be cut drastically by the end of 1986. Its use fell sharply, and it was banned in US cars and trucks in 1995. US blood-lead levels declined by 78 percent from 1978 to 1991. In July 2021, Algeria was the last country to sell leaded gasoline, just short of 100 years of poisoning. The UN estimates that leaded gasoline caused 1.2 million premature deaths every year.
Jessica Reyes showed evidence that banning lead in gasoline resulted in a drop in crime as children’s mental development was no longer being harmed by lead.
A Small Afterlife
TEL is still used in some gasoline fueled aircraft and off-road vehicles, so the poisoning is still happening, just at a much-reduced rate. The only legal manufacturer is Innospec in England. It has been fined for dangerous conditions and bribery of officials in Iraq and Indonesia.
They Knew
Du Pont’s Chair in 1922 wrote that TEL is “a colorless liquid of sweetish odor, very poisonous if absorbed through the skin, resulting in lead poisoning almost immediately.” But for decades after, the manufacturing companies denied this.
Midgley knew it was poisonous: he was poisoned in 1923. But for years the makers ducked, hid research, or produced false reports, delayed, made false claims — anything to stop losing money.
The actions of the corporations making TEL is a familiar story. The tobacco companies did the same, denying for years the fact that cigarettes kill. Pesticide makers have also refused to let science get in the way of profit. Worst of all is the unholy alliance of car makers, oil and coal companies, banks, and their friendly governments in refusing to deal with climate change.
At least the first commercial sellers of tobacco in 14th century Europe could claim they did not know it caused cancer. Similarly, the first commercial coal merchants, going back hundreds of years, would not know that burning it would cause climate change. These were unforeseen effects. This, of course, does not excuse the refusal of corporations to act one these effects were known. In the case of tetraethyl lead the deadly impact was known before it was even put up for sale — a truly criminal act, but no company has ever been prosecuted.
Capitalism has and always will put short-term profits first. Often big business misuses science and technology to make money while causing harm. The needs of public health or a healthy environment are not relevant to it. Public ownership and democratic control are vital to release research from the prison of profits.
