Millions of mental diagnoses in the US possibly linked to lead in gasoline, study finds -

A research paper published today in The Journal of Child Psychology and Psychiatry suggests that over 150 million Americans may have been exposed to dangerous levels of lead. The study found a link between lead in gasoline and the increase in the number of mental health conditions in the US. 

While leaded gasoline has been banned for cars since the mid-90s, it is still present in the lives of many Americans through things such as water pipes. How serious is this and what is the government doing about it? Click on to find out.  

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Research -

A study called ‘Contribution of childhood lead exposure to psychopathology in the US population over the past 75 years’ published on December 4 found a link between lead exposure and mental disorder diagnosis.

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Research -

The paper, published in The Journal of Child Psychology and Psychiatry, attributes about 151 million mental disorder diagnoses to lead exposure.

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Findings -

The research. conducted by Dr. Aaron Reuben and professors Michael McFarland and Mathew Hauer at Florida State University, suggests that Americans born before 1996 are the most affected. 

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Findings -

The study found that “Lead-associated mental health and personality differences were most pronounced for cohorts born from 1966 through 1986 (Generation X).”

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Lead exposure -

According to the study, this may be the result of lead exposure in gasoline. Lead was added to gasoline in 1923, and while unleaded gas is the norm nowadays, it was a reality for many years.

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The end of leaded gasoline -

The US did not start phasing out lead in gasoline until the 1980s, and leaded gasoline for cars was not banned in the US until 1996.

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It impacted millions of Americans -

“Millions of Americans are walking around with an unknown, invisible history of lead exposure that has likely influenced for the worse how they think, feel and behave,” said Dr. Reuben.

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Shifts in mental health -

"We saw very significant shifts in mental health across generations of Americans, meaning many more people experienced psychiatric problems than would have if we had never added lead to gasoline," explained Professor Hauer.

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The impact of lead on the human body -

Lead is a heavy metal that is toxic to humans. Lead is neurotoxic, so it can have a severe impact on the brain. Not only can it erode brain cells, but it can also alter brain function.

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The impact of lead on the human body -

Lead can indeed disrupt brain development and play a role in a number of mental health issues, including depression, anxiety, and ADHD.

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The impact of lead on the human body -

“It also changed personalities. We believe that (lead exposure) makes people a little less conscientious—so less well organized, less detail-oriented, less likely to be able to pursue their goals in an organized way, and more neurotic,” explains Dr. Reuben.

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It's not natural -

"Humans are not adapted to be exposed to lead at the levels we have been exposed to over the past century," he added.

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Previous study -

A previous study conducted by Dr. Reuben suggested that half of the American population was exposed to adverse lead levels in early childhood.

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Previous study -

The study estimated that lead was responsible for the loss of 824,097,690 IQ points in 2015 alone.

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Leaded gasoline is still used -

While regular cars are no longer running on leaded gas, many other vehicles still are. These include some planes, some farm and marine equipment, and some race cars.

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Lead is still being used -

Before lead in gasoline was banned in 1996, other sources of lead were phased out. Lead was removed from paint in 1978 and from pipes in 1986.

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Lead is still being used -

Lead is however still present in many old houses. This means that if you’re living in a house built before these years you may still be at risk.

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EPA regulation -

Because some old American cities still have lead pipes in their water system, the Environmental Protection Agency issued regulations in October 2024 to replace them in the next 10 years.

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EPA regulation -

The Lead and Copper Rule Improvements (LCRI) aim to help protect millions of Americans from lead exposure in drinking water.

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EPA regulation -

According to EPA estimates, every year it will “protect up to 900,000 infants from having a low birth weight, and prevent Attention-Deficit Hyperactivity Disorder (ADHD) in up to 2,600 children.”

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EPA regulation -

The regulation also aims to “reduce up to 1,500 cases of premature death from heart disease, and prevent up to 200,000 IQ points lost in children.”

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It can be in the soil too -

Even if your home and water supplies are lead-free, your soil may be contaminated. This is especially relevant if you're planting food or doing renovations that involve disturbing the soil.

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It can be in the soil too -

“The (Environmental Protection Agency) recently lowered its soil screening level, and it means that possibly one in four households in the US has soil lead that would now be deemed potentially hazardous,” said Dr. Reuben.

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What to do if you’ve been exposed? -

It’s not clear if there is anything that can be done for those potentially exposed to lead, other than trying to have a healthy lifestyle to minimize the possibility of more damage being made.

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What’s next? -

Dr. Bruce Lanphear, a population health scientist at Simon Fraser University in Canada, stresses that the government should ensure we live in a lead-free environment.

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The role of the government -

“We really need regulatory agencies like the FDA to make sure there’s not lead in the baby food,” he said.

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Working towards a lead-free world -

“Finding ways to deal with the 20 million homes that still contain lead hazards, getting rid of leaded aviation fuel, these are not things that people can do. This is what the government and regulatory agencies need to do,” added Dr. Lanphear.

Sources: (CNN) (Medical Xpress) (EPA) (The Journal of Child Psychology and Psychiatry)

See also: These are the most dangerous things in your home

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