Lead in gasoline linked to cognitive impairment in Gen X — New study

Researchers have warned that lead exposure is toxic to the brain, and high exposure can cause cognitive impairment.

According to them, the greatest increases in mental health problems were seen in Generation X, which was born between 1966 and 1986, and coincided with the highest consumption of leaded gasoline during that period.

A major source of lead exposure in the 1960s and 1970s was atmospheric pollution due to leaded gasoline.

Preliminary findings from a large, novel study reported that exposure to moderate levels of lead from gasoline during the 1960s and early 1970s is linked to a 20 per cent increased risk for memory problems later in life.

The study’s investigators found that older adults living in areas with moderate-to-extremely high historical atmospheric lead levels (HALLs) reported higher rates of memory problems than those living in areas with low lead exposure.

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These associations remained consistent across two periods and after adjusting for key demographic factors in the findings presentation at the 2025 Alzheimer’s Association International Conference (AAIC).

Eric Brown, MD, who is an associate scientist and the associate chief of geriatric psychiatry at the Centre for Addiction and Mental Health in Toronto, Ontario, Canada, and also a study investigator, remarked, “In someone who’s presenting with a memory problem, it’s very important to think broadly about possible causes, and that can include lead exposure.”

According to him, “It is important to understand the link between cognitive impairment and past lead exposure, said Brown. “Did this exposure have an impact on rates of dementia, and if it did, is there something we can learn from it?”

Kathryn Conlon, PhD, associate professor of environmental epidemiology, School of Medicine, University of California, Davis, said in a press release in a release declared, “Our results indicate that lead exposure in adulthood could contribute to worse cognitive performance within a few years.”

Dr Conlon added that despite tremendous progress on lead abatement, studies have shown there is no safe level of exposure, and half of US children have detectable levels of lead in their blood.

The study mapped HALLs using measurements obtained by the US Environmental Protection Agency from 1960 to 1974, a period of high leaded gasoline combustion.

The investigators also obtained data on self-reported memory problems from the American Community Survey, an annual demographics survey conducted by the Census Bureau, in two periods: 2012-2017 (n = 368,208) and 2018-2021 (n = 276,476).

Between 1940 and 2015, the data showed that those most exposed to lead—Generation X, who were born between 1966 and 1986—had the largest increases in mental health issues. Those born between 1966 and 1970 were most affected, aligning with the peak use of leaded gasoline during that time, researchers noted.

Previous research has shown that lead exposure is toxic to the brain, and high exposure can cause cognitive impairment.

Although leaded gasoline has been phased out, lead exposure remains a concern due to its presence in paint, plumbing, and water distribution systems, where drinking water was contaminated with lead about a decade ago.

The risks are particularly greater for vulnerable populations, such as those who are economically and socially disadvantaged and Indigenous hunters, who may be exposed through consumption of wild game contaminated by lead bullets.