When the UNEP launched its campaign in 2002, many major powers had already quit using the fuel, including the United States, China and India.

The use of leaded petrol has been eradicated from the globe, a milestone that will prevent more than 1.2 million premature deaths and save world economies over $2.4 trillion annually, the UN Environment Programme (UNEP) said Monday.

Nearly a century after doctors first issued warnings about the toxic effects of leaded petrol, Algeria—the last country to use the —exhausted its supplies last month, UNEP said, calling the news a landmark win in the fight for .

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

Even as recently as two decades ago, more than 100 countries around the world were still using leaded petrol, despite studies linking it to premature deaths, and soil and air pollution.

Concerns were raised as early as 1924, when dozens of workers were hospitalised and five declared dead after suffering convulsions at a refinery run by US giant Standard Oil, nicknamed the "looney gas building" by staff.

Nevertheless, until the 1970s almost all the gasoline sold across the globe contained lead.

When UNEP launched its campaign in 2002, many major economic powers had already stopped using the fuel, including the United States, China and India. But the situation in lower-income nations remained dire.

World map showing the progression of bans on toxic leaded petrol after the last country, Algeria, ended its use in July.

'End of a toxic era'

By 2016, after North Korea, Myanmar and Afghanistan stopped selling leaded petrol, only a handful of countries were still operating service stations providing the fuel, with Algeria finally following Iraq and Yemen in ending its reliance on the pollutant.

UNEP said in a statement that the eradication of leaded petrol would "prevent more than 1.2 million per year, increase IQ points among children, save $2.44 trillion (2.07 trillion euros) for the , and decrease crime rates."

The agency said the dollar figure came from a 2010 study led by scientists at California State University at Northridge.

Its chief factors were the benefits of better health for the overall economy; lower medical costs; and a dip in criminal activity—higher crime rates have previously been linked to exposure to leaded fuel.

UNEP warned that in general must still be drastically reduced to stave off the frightening effects of climate change.

The UNEP said the eradication of leaded petrol would prevent more than 1.2 million premature deaths each year.

Greenpeace hailed the news as "a celebration of the end of one toxic era."

"It clearly shows that if we can phase out one of the most dangerous polluting fuels in the 20th century, we can absolutely phase out all fossil fuels," said Thandile Chinyavanhu, climate and energy campaigner at Greenpeace Africa.

"Africa's governments must give no more excuses for the fossil fuel industry," she added.

Globally, vehicle sales are set to climb exponentially, particularly in emerging markets.

"The transport sector is responsible for nearly a quarter of energy-related global greenhouse gas emissions and is set to grow to one third by 2050," UNEP said, adding that 1.2 billion new vehicles would hit the streets in the coming decades.

"This includes millions of poor-quality used vehicles exported from Europe, the United States and Japan, to mid- and low-income countries.

Vehicle sales are set to climb globally exponentially, particularly in emerging markets.

"This contributes to planet warming and air polluting traffic and (is) bound to cause accidents," the global body said.

Earlier this month, a bombshell report by the UN's Intergovernmental Panel on Climate Change (IPCC) warned that Earth's average temperature would be 1.5 degrees Celsius (2.7 degrees Fahrenheit) warmer around 2030 compared to pre-industrial times.

A decade earlier than projected, the rise has raised alarm bells about the use of fossil fuels.