A recent study published in the Journal of Child Psychology and Psychiatry reveals that millions of Americans, especially those born between 1966 and 1986, may be dealing with psychiatric disorders linked to childhood exposure to leaded gasoline, Fortune reports.
The study estimates that childhood lead exposure through car exhaust has contributed to mental health challenges, including depression, anxiety, and hyperactivity.
According to the research, led by Aaron Reuben, a postdoctoral scholar in neuropsychology at Duke University, and colleagues Michael McFarland and Mathew Hauer at Florida State University, over half of the US population was exposed to “neurotoxic levels” of lead due to leaded gasoline, which was widely used until its phase-out in 1996.
The study’s findings indicate that Generation X—those born between 1966 and 1986—was the most affected, as this group was particularly vulnerable during the peak years of leaded gasoline use. The study suggests that individuals in this generation have seen a significant increase in mental health symptoms compared to others, with many experiencing psychiatric disorders directly linked to early lead exposure.
In an effort to better understand the effects, the researchers combined blood-lead level data from the National Health and Nutrition Examination Surveys (NHANES) with historical leaded-gasoline data, estimating childhood blood-lead levels from 1940 to 2015. The researchers then used these figures to calculate the prevalence of mental health disorders associated with lead exposure. The team’s findings estimate that over 150 million cases of psychiatric disorders over the past 75 years can be attributed to childhood exposure to leaded gasoline.
“Many more people experienced psychiatric problems than would have if we had never added lead to gasoline,” said Mathew Hauer, co-author of the study.
While the research identifies a link between lead exposure and mental health disorders, the researchers caution that it does not establish direct causation.
The study’s findings are part of ongoing efforts to understand the long-term consequences of lead exposure, which has been linked to developmental delays, learning difficulties, and emotional issues, especially in children. Lead exposure, particularly during childhood, can have serious and lasting effects on brain development, potentially causing cognitive impairments and emotional regulation difficulties. Small amounts of lead can lead to a range of health problems, from developmental delays in children to memory issues and mood disorders in adults.
The research also underscores the dangers of lead exposure, noting that even low levels of lead can lead to severe health complications. Children under six are particularly vulnerable to lead’s effects, which can cause developmental delays, learning difficulties, irritability, and, in some cases, more severe consequences like hearing loss or seizures.
“Humans are not adapted to be exposed to lead at the levels we have been exposed to over the past century… We have very few effective measures for dealing with lead once it is in the body, and many of us have been exposed to levels 1,000 to 10,000 times more than what is natural,” said Aaron Reuben, the lead author of the study.
While this research sheds light on the potential long-term mental health impacts of lead exposure, it also calls for further studies to understand all sources of lead exposure, including from lead pipes and contaminated food and soil.
