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Leaded gasoline has been a major problem for the world for a long time. As of last year, most of the world has stopped selling the last bits of leaded gasoline. However, from the 1920s – when leaded gas was invented – through 1996, most of the world still used leaded gas extensively, and now we are paying the price. 

gas station attendant fills up gas tank in black and white
Fill ‘er up? | Getty

Is leaded gas bad for you? 

Leaded gasoline is very dangerous for people to ingest. According to NewScientist, more than half of the US population could have a lower IQ from inhaling leaded gasoline fumes as children. The study found that the most concentrated IQ loss is found in the part of the population born in the 1960s and early 1970s. It was during this time that leaded gas use in cars was at its highest. 

If these leaded gas fumes enter the brain, they can disrupt nerve signaling and, at higher levels, kill brain cells. Young children are particularly susceptible due to the metal disrupting brain development. This is similar to breathing in lead paint fumes or ingesting lead paint flakes. 

Not that it helps, but it isn’t just Americans suffering from this IQ deficit. Aaron Reuben, a student Child Psychology researcher at Duke University, said, Similar effects have probably occurred in other high-income countries as well. “Patterns of lead use in gasoline throughout the last century were very similar across developed countries.”

Reuben and his colleagues used data from the national survey to figure out the circulating lead levels of over 11,600 children aged 1 to 5 years from blood samples drawn between 1976 and 2016. Since the same data didn’t exist before 1976, the team estimated the blood lead levels from 1940-1975 based on lead fuel use at the time. Once they had their data and estimations, the team used an established formula to calculate how the present lead levels would affect IQ. The results were eye-opening. 

How hard were our IQs hit? 

The findings suggest that likely over half of the American population were exposed to enough leaded gas to elevate the lead levels in their blood as children. On average, the study found that Americans have a 2.9-point lower IQ. What’s worse is the tail-end of baby boomers have an IQ 5.9 points lower on average than the rest of the world. 

Another study in the 1970s first discovered this link between lead levels in the blood in children and their performance in school. It was found that tiny lead particles survive the burning process and can exit the car via the exhaust.

Once the leaded gas fumes enter the air, people can breathe it in, entering the bloodstream and eventually getting to the brain. For young people whose minds are still developing, this can cause a lower IQ and other developmental issues. 

Is leaded gasoline illegal? 

As of 1996, the sale of leaded gasoline in America was outlawed. For the UK, leaded gas was banned starting in 2000. Even though it’s been nearly 30 years since we stopped using the nasty fuel, it doesn’t mean we still aren’t paying for it. “The long legacy is really important. The effects can last for a significant amount of time. This could be the case with other toxins.”

“The long legacy is really important. The effects can last for a significant amount of time. This could be the case with other toxins.”


Read more on the study here