151M Psychiatric Disorders Tied to Leaded Gas

Exposure to lead from car exhaust made generations of Americans more depressed, anxious, inattentive or hyperactive, and more inclined to be neurotic, according to new research that may prove especially alarming to Generation X. Researchers looked at levels of lead in child blood samples from 1940 to 2015 as well as estimates of historical lead exposure to determine the impact on early development. They found leaded gasoline, banned in 1996, was the direct cause of 151 million psychiatric disorders, including anxiety, depression, and ADHD, and likely a major contributing risk factor in other psychiatric conditions, including schizophrenia, over 75 years, with those born between 1965 and 1980 showing the highest rates of symptoms, per Jalopnik.

Lead was added to gasoline to improve engine performance beginning in the 1920s. Use of leaded gas increased after World War II, per NBC News, and hit peak use in the 1960s and '70s, before it was found to damage catalytic converters. Those born between 1966 and 1986, and particularly between 1966 and 1970, had the most-pronounced mental health and personality differences associated with lead exposure, while those born around 1940 and 2015 had the lowest rates of lead-associated mental illness and lead exposure, according to the study published Wednesday in the Journal of Child Psychology and Psychiatry.

"I tend to think of Generation X as 'generation lead,'" says co-author Aaron Reuben, an assistant professor of clinical neuropsychology at the University of Virginia, per USA Today. "In the '60s, '70s and '80s, folks were walking around with an average blood lead value that today would trigger clinical follow-up." On the bright side, "studies like ours today add more evidence that removing lead from our environment and not putting it there in the first place has more benefits than we previously understood," Reuben says, per NBC. His previous research found half of Americans alive in 2015 were likely exposed to damaging levels of lead as kids and that exposure to leaded gasoline caused Americans to lose 824 million IQ points. (More lead stories.)