1921: Researchers find that adding a small amount of tetraethyl lead to gasoline eliminates engine knock. Generations of children and refinery workers will suffer from lead exposure.

Researcher Thomas Midgley was working for General Motors under the legendary Charles Kettering to develop a fuel additive that could silence the harmful “knock” in high-compression engines. Knocking occurs when some unburned fuel-air mixture explodes in the wrong place and time in an engine’s four-stroke cycle. It can cause loss of power, engine wear and pollution.

Midgley had already tried hundreds of compounds to no avail, tracking his process on a pegboard that allowed him to compare tests — a shining example of scientific progress through rigorous research. A chemist delivered a small amount of tetraethyl lead, or TEL, on the morning of Dec. 9.

When Midgley added the TEL to the fuel and started the one-cylinder test engine, the engine knock was nowhere to be heard.

GM and Standard Oil of New Jersey (forerunner of Exxon) formed the Ethyl Corporation shortly thereafter to produce TEL. The company’s name was carefully chosen to avoid the use of the word “lead,” but safeguards at the factory weren’t as effective.

Not long after it opened, workers at the Ethyl plant began suffering from lead poisoning. Two workers died from exposure to what the press called “loony gas.”

Midgley himself suffered from lead poisoning and took a vacation to “get a large supply of fresh air.” Ironically, Midgley would later develop Freon, a refrigerant that cooled indoor air for nearly half a century.

Even with TEL’s dominance, Midgley and Kettering remained interested in using ethanol as an additive and “fuel of the future” that could eventually replace leaded gasoline. Their efforts were hampered by the higher cost of producing ethanol and the fact that even legitimate scientists had a hard time obtaining any form of pure alcohol during Prohibition.

From the 1930s through the ’60s, lead remained the additive of choice. On a 1940s episode of the Burns and Allen radio show, the stars joked about a woman named Ethel Knox, whom an oil company paid to change her name. George Burns replied that his first name used to be Asbestos, and the audience roared.

Researchers at Ethyl Corporation, led by chief medical consultant Dr. Robert Kehoe, continued to claim that exposure to the small level of lead present in gasoline had no ill effects on health.

Unfortunately, those small, acceptable amounts of lead from exhaust and fuel spillage remained stockpiled in water and soil, which geochemist Clair Patterson discovered in 1965 while attempting to measure the age of the Earth. Examining the lead content of rocks and ocean-sediment samples, Patterson found that levels of lead had increased alarmingly since the advent of leaded fuel.

After the efforts of concerned scientists such as Patterson and Phillip Landrigan, the newly formed Environmental Protection Agency began to gradually phase out lead as a fuel additive starting in 1976. Over the next 15 years, the concentration of lead in the bloodstream of Americans dropped 78 percent.

So what’s wrong with a little lead between friends? Consider that researchers have tied even small amounts of lead exposure to low IQ, aggression, attention disorders and delinquency. A University of Pittsburgh study found that between 18 and 38 percent of crime could be tied to lead exposure. Remember the New York crime wave of the 1970s and ’80s? Some researchers say it was all due to lead poisoning.

After lead was completely removed from the U.S. fuel supply by 1986, refiners added MTBE and, finally, ethanol. And while Midgley’s discovery may have saved countless pistons, it continues to take a toll on human life in countries where TEL is still added to gasoline.

Source: Prof. Bill Kovarik, others

Photo: catchesthelight/flickr