Exposure to the heavy metal lead in childhood may affect mental health and personality in adulthood, according to a study involving people who grew up when lead levels in gasoline were higher. In the United States, unleaded gasoline was introduced in the 1970s and leaded gasoline was eliminated in 1996. Most U.S. adults over age 30 were exposed to lead when they were children — in the atmosphere, in soil, or in homes with leaded paint or plumbing.
The study was conducted at Duke University in Durham, North Carolina, and published in JAMA Psychiatry. It involved more than 1,000 people born in New Zealand between 1972 and 1972. (At that time, gasoline lead levels in New Zealand were among the highest in the world.)
The researchers found that mental illness and difficult personality traits were more common in adults who had higher blood levels of lead as kids. About 94 percent of study participants had blood levels that exceeded current guidelines (above 5 micrograms per deciliter of blood, 5 ug/dL) at age 11.
According to the Duke researchers, study participants who had high lead levels as kids had increased risk for psychiatric disorders like major depressive disorder, substance abuse, generalized anxiety disorder, obsessive-compulsive disorder (OCD), and others by age 38, and were more likely to be described by friends and family members as having neurotic, less agreeable, and less conscientious personalities compared to those who had lower childhood lead levels.
Sourced from: JAMA Psychiatry