Exposure to lead in gasoline during childhood caused many millions of excess cases of psychiatric disorders over the past 75 years, a new study estimated.
Lead was banned in automobile fuel in 1996. The study, published Wednesday in the Journal of Child Psychology and Psychiatry, examined its lasting impact in the United States by analyzing blood lead levels in children between 1940 and 2015. According to the findings, it is estimated that the national population experienced 151 million mental disorders attributable to exposure to lead from automobile exhaust during early childhood development.
According to the study, the exposure caused several generations of Americans were more depressed, anxious, inattentive or hyperactive.
The researchers – a group from Duke University, Florida State University and the Medical University of South Carolina – found that exposure also decreased people’s ability to control their impulses and made them more likely to be neurotic.
According to the study, the mental health and personality differences associated with lead were most pronounced in people born between 1966 and 1986. Of that group, the greatest burden of lead-related mental illness was among members of Generation 1966 and 1970, which coincides with the peak of leaded gasoline use in the mid-1970s and mid-1970s.
People born during those years “can’t go back in time and change that,” said Aaron Reuben, one of the study’s authors and a postdoctoral fellow in Neuropsychology at Duke and the Medical University of South Carolina.
“Studies like ours today add more evidence that removing lead from our environment and not using it in the first place It has more benefits than we understood until now“he commented.
According to the study, groups born around 1940 and 2015 had lower lead exposure and suffered fewer lead-related mental illnesses.
Although it is no longer found in gasoline, lead is still present in other sources, such as some toys imported from other countries, water pipes, parts of the floors and paint in old houses. Lead paint was banned in 1978.
According to the Centers for Disease Control and Prevention (CDC), there is no safe level of lead exposure. Even small amounts are associated with developmental and learning difficulties, since lead exposure is known to damage the brain, nervous and reproductive systems. Children under 6 years old are most vulnerable to lead poisoning.
The study released Wednesday combines data on blood lead levels and estimates of historical lead exposure with findings from previous studies, including a 2019 investigation of nearly 600 New Zealand residents that followed children exposed to lead and measured your mental health for more than three decades.
Reuben, who was the lead author of that study, said the new research “doesn’t create new information about whether lead causes harm, nor are we saying this is a study that proves causality: We’re really just taking the existing evidence and applying it.” to the entire American population.
“We are not at all concerned that we have somehow overestimated the damage,” he added.
Dr. Lisa Fortuna, president of the American Psychiatric Association’s Council on Children, Adolescents and Their Families, praised the study.
“We don’t often see many studies looking at environmental or toxin-related risks potentially linked to the development of high rates of mental health problems in populations,” he said. “The research sheds some light on the profound and lasting impact of environmental factors“.
The study’s conclusions should not be a cause for panic, Fortuna stressed.
“It doesn’t mean that people are, I would say, trapped in a mental illness. It doesn’t mean that they’re necessarily going to be at higher risk,” he stressed. “It’s really a question of, ‘This is what’s happened at the population level.'”
The study comes a couple of years after Reuben and other researchers found that exposure to leaded gasoline reduces IQ of approximately half of the American population. That study estimated that childhood exposure to lead in gasoline cost Americans about 824 million IQ points.
Lead was originally added to gasoline to improve engine performance. The use of leaded gasoline increased after World War II until it became detrimental to catalytic converters, which became mandatory in the 1970s. Some of the dangers of lead were known long before its use was banned in the gasoline, but reducing exposure to this metal did not become a federal priority until many years later.
Currently lead testing recommended to all young children, with treatments such as chelation therapy to remove the venom if levels are high.
Reuben stated that prevention is the best way to keep the population safe.
“In the United States we have done a lot to reduce lead exposure. Blood lead levels have gone down a lot, but they could go down even more,” he said. “I hope we can learn from history about the damage we caused in the United States, and try to apply that going forward.”
