Living during the '60s or '70s may have subjected your brain to an unusually high level of risk due to potential exposure to certain variables.

In the United States, a new study has shed light on a potential connection between historic lead exposure and memory problems in older adults.

Lead was initially added to gasoline to improve engine performance and prevent a knocking or rattling sound. However, it was soon discovered that lead was harmful to the maturing brains and nervous systems of young children, causing developmental, learning, and behavioral difficulties. Despite this, leaded gasoline was widely used as car fuel in the US from the 1920s until the 1970s.

The use of leaded fuel in on-road vehicles was gradually reduced over two decades, with a full ban taking effect in 1996. However, the legacy of lead exposure lingers. Over 88% of the US population had dangerously high levels of lead in their blood between 1960 and 1974. This high exposure rate extended to half of the US population, more than 170 million people, who were exposed to high lead levels in early childhood.

Soil and water contamination persisted due to the use of leaded fuel. Today, cities with high concentrations of leaded aviation gasoline are often near airports with significant piston-engine aircraft activity, such as Van Nuys in California and areas around Mojave and Santa Monica. Lead exposure risks remain high in industries like aviation fueling, racing fuel applications, and lead smelting or recycling operations.

Older adults living within 3 miles of a lead-releasing facility face greater odds of memory and thinking problems than those living farther away. A new study indicates that if you lived in an area with high levels of atmospheric lead between 1960 and 1974, you're 20% more likely to suffer memory problems later in life.

However, measuring long-term lead exposure presents challenges. Lead levels in the blood primarily reflect recent or ongoing exposure, but lead is stored in the bones for significantly longer than in the blood. Measuring this presents challenges, and technology such as K-X-ray fluorescence, which has been used in research studies, is not available to the general public.

Researchers recommend reducing other dementia risk factors, such as high blood pressure, smoking, and loneliness, for those concerned about decades-old lead exposure. They also caution that this study does not prove causation, but rather suggests a correlation that warrants further investigation.

Another study shared at AAIC revealed that lead exposure, even at low levels, can contribute to the accumulation of abnormal tau and amyloid beta proteins associated with Alzheimer's disease in brain cells. This finding adds to the growing body of evidence linking lead exposure to cognitive decline and neurological issues in adults.

With over 6 million Americans suffering from dementia, which causes memory loss, concentration, and judgment problems and is responsible for over 100,000 deaths each year, understanding and addressing the long-term effects of lead exposure is crucial. While the phase-out of leaded gasoline was a significant step towards reducing lead exposure, the legacy of this toxic substance continues to impact public health.