Global lead exposure still costs trillions and endangers children, NUS study finds

Despite the global phase-out of leaded gasoline, lead pollution continues to threaten health and widen inequality, with low- and middle-income countries bearing the brunt

SINGAPORE, Oct. 12, 2025 /PRNewswire/ -- Lead poisoning was once thought to largely be a problem of the past, as the globe gradually weaned itself off leaded gasoline in road vehicles in 2021. But has global lead pollution truly been resolved?

A new study led by Dr Chen Mengli, a Research Fellow from the Tropical Marine Science Institute at the National University of Singapore (NUS), in collaboration with researchers from Imperial College London, University of Warwick, University of Oxford, Jadavpur University, University of Michigan, Ann Arbor, Hebrew University of Jerusalem, Massachusetts Institute of Technology, and University of Bristol, showed the answer is not yet: lead exposure remains a pressing public health and economic challenge in the 21^st century. The researchers estimated that ongoing childhood lead exposure costs the world more than US$3.4 trillion in lost economic potential each year, with disproportionate impacts on low- and middle-income countries.

Published in the Communications Earth & Environment on 30 September 2025, the findings suggest that without stronger safeguards, the ever-increasing demand for electrification and poorly regulated recycling of lead-containing products could entrench global inequalities and set back decades of progress in children's health. To avert this, the researchers proposed a four-pronged strategy that policymakers and industries can act on today.

Lessons from history

Lead has been woven into human society for thousands of years, from the plumbing systems of the Roman Empire to the paints, pipes and industrial alloys still in use today. Its widespread use has left a toxic trail. Some of the earliest mass poisonings were linked to contaminated food and drink in Europe centuries ago. But the most recent incident came with the introduction of tetraethyl lead in gasoline in the 1920s, which for decades spewed millions of tonnes of the metal into the atmosphere.

By the 1970s, children across the world carried dangerously high blood lead levels, and the repercussions were severe, causing neurological damage, impaired development and countless premature deaths. The eventual ban on leaded gasoline, completed worldwide only in 2021, is heralded as one of the great public health victories of the modern era. Importantly, it showed that determined, coordinated global action could reduce exposure and save lives.

However, the team noted that the celebration of a "lead-free" world was premature. While blood lead levels fell in many high-income countries, they plateaued or even rose again in parts of Asia, Africa and Latin America. Legacy contamination from soils and infrastructure, coal combustion, numerous lead-laden products such as leaded paint, and informal recycling of lead-acid batteries and e-wastes have all kept exposure alive.

"The perception that the problem was solved has to change. New sources of exposure continue to emerge and the historical emitted lead keeps redistributing through various natural processes," added Dr Chen, who is also from the Department of Geography, Faculty of Arts and Social Sciences at NUS.

Today's exposure and economic toll

Lead production today exceeds 16 million tonnes a year, with about 85 per cent going into lead–acid batteries that power vehicles, telecommunications and backup energy systems. Annual production now exceeds the total lead emitted during the entire era of leaded gasoline.

Though these items can be recycled, much of the reprocessing occurs under unsafe conditions, particularly in low- and middle-income countries. Informal recycling sites, often located near homes and schools, expose workers and surrounding communities to hazardous levels of lead. Coal combustion, contaminated soils and the continued sale of lead-laden paints, toys, and even food products, further compound the risks.

The researchers noted from numerous literatures that health consequences are most severe for children. Even at low levels, lead can damage the developing brain, lowering IQ, impairing learning and contributing to behavioural issues. This burden is often carried across one's lifetime as the effects are irreversible. In particular, the team estimated that childhood exposure today translates into a global economic loss exceeding US$3.4 trillion annually, equivalent to over 2 per cent of the world's GDP.

Four-pronged approach to curb a resurgence 

The team highlighted that recognising the continuing risks is the first step towards preventing another global health crisis. The study outlined four urgent areas for action to safeguard public health and reduce inequality:

1. Manage the life cycle of lead-containing products. With demand for batteries and electronics rising, stronger oversight is needed to minimise leakage during production, use and disposal.
2. Eliminate unsafe and illicit sources. Informal recycling and lead-laden goods such as lead paints, glazed ceramics and adulterated spices continue to expose millions to hazardous levels of lead.
3. Strengthen monitoring and community involvement. Early detection of lead leakage is often underfunded. Advances in low-cost sensors and machine-learning-based tools, combined with local knowledge, can help identify and address hotspots more effectively.
4. Capture the full socio-economic cost. Lead exposure disproportionately harms disadvantaged populations. Better models and population-level data are needed to quantify long-term impacts on health, education and productivity, as well as guiding equitable policy responses.

"The world rightly celebrated the phase-out of leaded gasoline as a triumph of international cooperation," she said. "But the problem of lead exposure has not yet gone away. Unless we remain vigilant about both new sources of exposure and the legacy of lead in the environment, we may risk repeating the same tragedy," Dr Chen emphasised.

Read more at: https://news.nus.edu.sg/global-lead-exposure-costs-trillions-endangers-children/   

SOURCE National University of Singapore