A new study has revealed that lead exposure is responsible for an estimated 3.5 million deaths from cardiovascular disease worldwide in 2023 alone, far more than previously understood.
The research, led by the Institute for Health Metrics and Evaluation at the University of Washington, marks a significant shift in how scientists understand lead’s impact on heart health. While lead has long been known to harm children’s brain development, its role in causing heart disease in adults has been underestimated.
The study found that lead is now the eighth leading risk factor for death globally, up from 18th in previous estimates, and the second most deadly environmental risk after air pollution.
The researchers analysed data from more than 42,000 adults in the United States, tracking their lead exposure over time. They found that even low levels of lead accumulation in the body significantly increase the risk of dying from heart disease.
For example, someone with a bone lead level of 10 micrograms per gram had a 16% higher risk of cardiovascular death compared with preindustrial levels. At 25 micrograms per gram, the risk jumped to 41%.
Significantly, the study showed that lead damages the heart through multiple pathways, not just by raising blood pressure, as was previously thought. Lead causes oxidative stress, damages blood vessels, and accelerates the buildup of plaque in arteries.
The study did not pinpoint a single source of lead exposure, instead estimating total exposure from all combined sources over time. It highlights legacy pollution from leaded gasoline and paint as the main historical drivers, while ongoing risks today come from sources such as battery recycling, contaminated water and consumer products. Overall, past gasoline use explains much of the long-term burden, with industrial activities and residual contamination continuing to drive exposure.
The burden of lead-attributable heart disease falls unevenly across the world. The highest rates were found in North Africa and the Middle East, South Asia, and Central Europe, Eastern Europe, and Central Asia. South Asia alone accounted for more than 20 million disability-adjusted life-years lost to lead-related heart disease.
While blood lead levels have declined globally since the phaseout of leaded gasoline, the study found that bone lead levels, which reflect cumulative lifetime exposure, did not peak until around 2001. This means that older generations who grew up during peak lead exposure years continue to carry that risk into old age.
The study’s findings suggest that current efforts to reduce lead exposure—while important—are insufficient. The researchers call for strengthened surveillance, tighter regulation, and remediation of contaminated sites, particularly in low- and middle-income countries where exposure remains high.
They also note that some interventions later in life, such as chelation therapy, may reverse some of the cardiovascular damage caused by lead. However, the most effective approach remains preventing exposure in the first place.
The authors conclude: ‘Cumulative lead exposure remains a major, preventable contributor to global cardiovascular mortality.
‘As each person’s risk continues to increase with each day of accumulating lead exposure, there is urgency to accelerate lead exposure reductions to avert future burden.’
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