The Globe's Last Supply of Leaded Gasoline is Gone, Ending a Toxic Era

Leaded gasoline's century-long reign of destruction is over.

The final holdout, Algeria, used up the last of its stockpile of leaded gasoline in July. That's according to the U.N. Environment Programme, which has spent 19 years trying to eliminate leaded gasoline around the globe.

"The successful enforcement of the ban on leaded petrol is a huge milestone for global health and our environment," Inger Andersen, the UNEP's executive director, said Monday.

The U.N. estimates that the phaseout of the toxic fuel will save $2.44 trillion dollars per year, thanks to improved health and lower crime rates, and prevent more than 1.2 million premature deaths.

In 1921, researchers at General Motors discovered that adding a compound called tetraethyl lead to gasoline could improve engine performance. (Not-so-fun fact: Thomas Midgley Jr., a scientist who played a key role in what proved to be a calamitous discovery, also developed chlorofluorocarbons, a class of refrigerants that went on to destroy the ozone layer.)

There were other additives that could serve the same purpose — today, ethanol is widely used as a far safer alternative. But lead quickly became the standard.

At the time, it was well known that lead was a poison, and there was concern over the risk to workers exposed to the dangerous additive.

But researchers working for automakers, oil companies and chemical giants said that the general public would not be harmed by low levels of exposure through leaded gasoline.

That turned out to be disastrously false. Children, in particular, are vulnerable to even minute amounts of lead exposure, and the use of leaded gasoline has been linked to lower IQs and higher rates of violent crime. Lead exposure also causes heart disease, cancer and other diseases, and when burned in an engine, lead can easily contaminates air, water and soil.

It took decades for scientists to establish the damage that leaded gasoline was causing. By that point, virtually all the gasoline in the world had lead added to it.