Science Good News #24. Lead.

If you are going to write an essay on lead, where would you begin?

You could begin in Flint Michigan, and the story of that city’s mismanagement of their drinking water supply. Or you could begin in Omaha and the story of how lead released into the atmosphere causes an EPA super fund site that is over 17,000 acres in size. Or you could begin on the shores of beautiful Lake Coeur d’Alene, Idaho, where decades of mining have left a legacy of over 75 million tons of sediment at the bottom of the lake, contaminated with lead and other metals.

You could also begin with a story about leaded gasoline, a story that has come to a very satisfying end.

Lead was initially added to gasoline, in the form of tetra ethyl lead in 1921 to prevent engine knock, the premature ignition of gasoline with the engine’s cylinders. Engine knock killed engine efficiency and gas mileage, therefore soon after reaching the market, leaded gasoline took over. Unfortunately, the lead in the gasoline, once combusted, entered the atmosphere then settled back to the ground. Leaded gasoline was covering vast areas of the country with a thin film of toxic material.

Just three years after the initiation of leaded gasoline use, 15 refinery workers died due to suspected lead poisoning. The poisonings caused the Surgeon General to set a voluntary standard for lead content in gasoline, which the refining industry followed. With the Clean Air Act of 1970, the newly formed Environmental Protection Agency was given authority to regulate chemicals that impaired human health, including leaded gasoline. Three years later a phase out program for leaded gasoline was initiated.

Internationally, Japan was the first to completely phase out the use of leaded gasoline in 1980, and very quickly other nations followed. In 1996, the United States kicked the habit and joined the team. A huge victory in the fight toward a world wide eradication of leaded gasoline occurred in the early 200’s when twenty five sub-Saharan African countries agreed to phase out leaded gasoline. At the time, though, there were still over 115 countries world-wide using tetra ethyl lead in gasoline, so the battle was far from over.

Ten years later, that number had dropped from 115 to 10. Campaigns were run in the remaining 10 countries, as well as in their neighboring trade partners, to show them that: unleaded gasoline would not hurt their cars, the amount of lead in the air dropped dramatically after leaded gas use was stopped, and that, most important of all, blood lead levels dropped precipitously when countries kicked th

e habit. By 2016, the number of users was down to three, Yemen, Iraq and Algeria.

The last holdout, Algeria just used up its remaining leaded gasoline stockpile in July 2021. And with the burning of the last drops of leaded gasoline, a century long legacy of leaded gasoline has come to a close.

World wide eradication programs work and the health of people benefit from it. The poster child for such eradication programs is small pox, a disease that has been eradicated since 1980. Other diseases are targeted for world-wide eradication including malaria, and it is no longer a question of if it will occur, but when.

While the eradication of a chemical from use will never reach the headlines to the degree that the eradication of a disease, such as small pox will, the cessation of leaded gasoline is a major public health victory.

And that is very good news!