Research estimates that there are 151 million psychiatric cases in the US due to lead exposure

In 1923, lead was added to gasoline for the first time to keep car engines healthy. However, the health of the car came at the expense of our own well-being.

A new study calculates that exposure to leaded car exhaust during childhood changed the mental health of the US population, making generations of Americans more depressed, anxious, inattentive or hyperactive.

The paper “Contribution of Childhood Exposure to Psychopathology in the US Population Over the Past 75 Years,” appears in the Journal for child psychology and psychiatry.

The study estimates that 151 million cases of psychiatric disorders over the past 75 years resulted from American children’s exposure to lead.

The findings by Aaron Reuben, a postdoctoral scholar in neuropsychology at Duke University, and colleagues at Florida State University, suggest that Americans born before 1996 experienced significantly more psychological distress due to lead, and likely experienced changes in their personality. that would have made them less successful and resilient in life.

Leaded gas for cars was banned in the US in 1996, but researchers say anyone born before then, and especially during the peak of its use in the 1960s and 1970s, had worryingly high lead exposure as children.

Lead is neurotoxic and can erode brain cells and alter brain function after entering the body. As such, there is no safe level of exposure at any point in life, health experts say. Young children are especially vulnerable to lead’s ability to hinder brain development and alter brain health. Unfortunately, regardless of age, our brains are ill-equipped to keep lead poisoning at bay.

Because water systems in older American cities still contain lead pipes, the EPA says issued regulations In October, cities will have 10 years to identify and replace lead pipes, and $2.6 billion to do so.

Earlier this year, the EPA also lowered lead levels in soil it considers potentially hazardous, resulting in an estimated one in four American households having soil that is potentially hazardous. require cleanup.

“Humans are not adapted to being exposed to lead at the levels we have been exposed to over the last century,” Reuben said. “We have very few effective measures to deal with lead once it is in the body, and many of us are exposed to levels 1,000 to 10,000 times higher than what is natural.”

Over the past century, lead has been used in paint, pipes, solder and, most disastrously, car fuel. Numerous studies have linked lead exposure to neurodevelopmental and mental health problems, particularly behavioral disorders, attention-deficit/hyperactivity disorder and depression. But until now it wasn’t clear how widespread symptoms of lead-related mental illness might have been.

To answer the complex question of how the use of lead gas left a lasting mark on human psychology for more than 75 years, Reuben and his co-authors turned to Michael McFarland and Mathew Hauer, both professors of sociology at Florida State University. turns to publicly available national data.

Using historical data about the US blood lead levels in childhood, use of lead gasAnd population statisticsthey determined the likely lifetime burden of lead exposure carried by every living American in 2015.

From this data, they estimated lead’s attack on mental health and personality by calculating “mental illness points” obtained from exposure to lead gas as a measure of its harmful effects on public health.

“This is the exact approach we have taken in the past to estimate lead’s harm to population cognitive ability and IQ,” McFarland said, noting that the research team had previously determined that lead has been around for the past century stole 824 million IQ points from the American population.

“We saw very significant shifts in mental health across generations of Americans,” Hauer said. “This means that many more people experienced psychiatric problems than would have been the case if we had never added lead to gasoline.” Lead exposure led to a greater number of diagnosable mental disorders, such as depression and anxiety, but also to a greater number of individuals experiencing milder problems that would affect their quality of life.

“For most people, the impact of lead would have been like a low-grade fever,” Reuben said. “You wouldn’t go to the hospital or seek treatment, but it would bother you slightly more than if you didn’t have a fever.”

Lead’s effect on brain health has also been linked to personality changes occurring nationally. “We estimate a population-level shift in neuroticism and conscientiousness,” McFarland said.

As of 2015, more than 170 million Americans (more than half of the U.S. population) had clinical concerns about lead levels in their blood as children, likely resulting in lower IQ and more mental health problems, likely putting them at higher risk. for other long-term health problems, such as an increase in cardiovascular disease.

Consumption of leaded gasoline rose rapidly in the early 1960s and peaked in the 1970s. As a result, Reuben and his colleagues found that virtually everyone born during those twenty years had almost certainly been exposed to harmful levels of lead from car exhaust. The generation with the greatest exposure to lead, Generation X (1965–1980), is believed to have experienced the greatest mental health losses.

“We are beginning to understand that past exposure to lead — even decades in the past — can affect our current health,” Reuben said. “Our task going forward will be to better understand the role lead has played in our nation’s health, and to ensure we protect today’s children from new lead exposure wherever it occurs.”