Florida State University

WEDNESDAY, Dec. 4, 2024 -- Decades of lead exposure from car exhaust altered the mental health of millions of Americans, making them more prone to depression, anxiety and ADHD, a new study claims. Lead was first added to gasoline in 1923 to help keep car engines healthy, researchers said. But lead is toxic to brain cells, and there’s no safe level of exposure at any point in life. Children are especially vulnerable, as lead is known to impair brain development. Leaded gas was banned in the United States in 1996, but anyone born before then -- especially during peak use in the 1960s and 1970s -- is at risk for toxic brain effects from car exhaust, researchers said. Such exposure has caused as many as 151 million cases of mental health disorder during the past 75 years, researchers reported. Americans born before leaded gas was banned have experienced significantly higher rates of mental health problems, and likely underwent changes in their personalities that made them less successful and resilient in life, the study concluded. “Humans are not adapted to be exposed to lead at the levels we have been exposed to over the past century,” said researcher Aaron Reuben , a postdoctoral scholar in neuropsychology at Duke University, in Durham, N.C. “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,” Reuben added in a university news release. For the study, Reuben and his colleagues analyzed historical data on blood-lead levels in U.S. children, patterns of leaded gasoline use in America and population statistics of mental health problems. This data allowed them to calculate “mental illness points” gained from exposure to leaded gas, researchers aid. “This is the exact approach we have taken in the past to estimate lead’s harms for population cognitive ability and IQ,” noted researcher Michael McFarland , a professor of sociology at Florida State University. Previous research from the team found that lead stole 824 million IQ points from the U.S. population over the past century. As of 2015, over 170 million Americans -- more than half the U.S. population -- had elevated levels of lead in their blood as children, likely blunting their IQ and putting them at high risk for mental health disorders, researchers said. Lead exposure is significantly linked to higher rates of mental disorders like depression and anxiety, researchers found. It also likely caused mild distress that impaired people’s quality of life without resulting in a full-blown psychiatric condition. The new study was published Dec. 4 in the Journal of Child Psychology and Psychiatry . “We saw very significant shifts in mental health across generations of Americans,” said researcher Mathew Hauer , a professor of sociology at Florida State. “Meaning many more people experienced psychiatric problems than would have if we had never added lead to gasoline.” Generation X (born 1965 to 1980) would have had the greatest lead exposures and the greatest mental health losses, the researchers concluded. “We are coming to understand that lead exposures from the past -- even decades in the past -- can influence our health today,” Reuben said. “Our job moving forward will be to better understand the role lead has played in the health of our country, and to make sure we protect today’s children from new lead exposures wherever they occur.” Whatever your topic of interest, subscribe to our newsletters to get the best of Drugs.com in your inbox.

WEDNESDAY, Dec. 4, 2024 -- Children's exposure to lead in the United States has had a significant impact on mental illness symptomatology and disadvantageous personality differences, according to a study published online Dec. 4 in the Journal of Child Psychology and Psychiatry . Michael J. McFarland, Ph.D., from Florida State University in Tallahassee, and colleagues combined serial, cross-sectional blood-lead level (BLL) data from National Health and Nutrition Examination Surveys with historic leaded-gasoline data to estimate U.S. childhood BLLs from 1940 to 2015. Population mental health symptom elevations from known lead-psychopathology associations were calculated. Assuming the published lead-psychopathology associations are causal, the researchers estimated that the U.S. population gained 602 million General Psychopathology factor points arising from leaded gasoline by 2015, reflecting an increase of 0.13 standard deviations in overall liability to mental illness and an estimated 151 million excess mental disorders due to exposure to lead. Standard deviation increases of 0.64 and 0.42 in population-level internalizing symptoms and attention-deficit/hyperactivity disorder symptoms, respectively, were identified on examination of specific disorder-domain symptoms. A 0.14-standard deviation increase in population-level neuroticism was seen, as was a 0.20-standard deviation decrease in conscientiousness. Cohorts born from 1966 to 1986 had the most pronounced lead-associated mental health and personality differences. "A significant burden of mental illness symptomatology and disadvantageous personality differences can be attributable to U.S. children’s exposure to lead over the past century," the authors write. "The contribution of legacy lead exposures to population health and disease may be much larger than previously assumed."

Evolutionary biologists have unearthed a new species of tiger beetle, deemed Eunota houstoniana, honoring the Houston region where it predominantly resides. Rice University evolutionary biologist Scott Egan and his research team have unearthed a new species of tiger beetle, deemed Eunota houstoniana, honoring the Houston region where it predominantly resides. The team employed cutting-edge genetic sequencing technology alongside traditional measurements of their physical appearance and geographic range data to redefine species boundaries within the Eunota circumpicta species complex. This approach, known as integrative taxonomy, allowed them to identify distinct biological entities previously overlooked. The study is published online in Nature Scientific Reports. "It is amazing that within the city limits of Houston, we still don't know all the species of insects or plants we share our region with," Egan said. "I'm always interested in learning more about the biodiversity of the Gulf Coast." The Eunota houstoniana was once considered synonymous with the more common Eunota circumpicta, but the team's research revealed significant differences, emphasizing the need for a refined process to species delineation. Eunota houstoniana exhibits distinct genetic and physical characteristics. It is slightly smaller in size, its metallic coloring is more subdued, and it has unique behavior and habitat preferences. Moreover, the new species gravitates towards saline soils often found near salt domes and oil extraction sites along the Gulf Coast. Its habitat ranges from coastal regions to inland areas, showcasing its adaptability and ecological significance. The discovery of Eunota houstoniana underscores the urgency of biodiversity conservation. Its habitats are increasingly jeopardized by urbanization and agricultural or industrial activities, and although newly discovered, Eunota houstoniana is likely a threatened species, according to Egan. "Because of all the growth around Houston, some of these populations have likely gone extinct while others have been hiding right out our back door," Egan said. Egan's research team for Eunota houstoniana includes lead author Dan Duran, department of environmental science at Rowan University; Robert Laroche, ecology and evolutionary biology Ph.D. student at Rice; Ethan Bull, undergraduate student at Rice; David Herrmann from Dallas; Will Godwin from Sam Houston State University; and Steve Roman, collection of arthropods at Florida State University. In a related project, Egan and Laroche recently described another new species from the same genus, the Eunota luecophasma, or the white ghost tiger beetle from West Texas, further highlighting the diversity and importance of these creatures in our region. "Hopefully, our integrative approach to species delimitation becomes the standard for the field of biology, where, unfortunately, many organisms have not had the same level of attention that the charismatic tiger beetles have had," Laroche said. Eunota houstoniana marks the 17th new species described by Egan and his collaborators during his 11 years at Rice. His work at Rice since 2013 has been instrumental in uncovering and describing previously unknown insect species in the state. In Texas, there are around 62 known species of tiger beetles, but that is likely an underestimate of the diversity that exists, according to Egan. By identifying and documenting such species, researchers like those in Egan's laboratory provide essential groundwork for conservation efforts.