The Biden administration's recently announced plan to replace all lead pipes in the U.S. is a reminder that the toxic metal remains a threat, even in a country that has largely banned its use. The smallest levels of lead exposure can cause a range of health damages over time, especially to children's brain development. Stanford researchers Stephen Luby and Jenna Forsyth have spent years examining the widespread presence of lead in low-income countries, including in some commonly consumed products. They led a perspective published Nov. 5 in The Lancet Public Health that tallies lead's global health and economic costs, and a study in the November issue of Science of the Total Environment that highlights the urgent challenge of lead contamination in South Asian turmeric.

"Lead is a remarkably harmful toxin," said Luby. "Even within the context of limited resources, we have to find ways to focus on reducing exposure to it."

Below, Luby, the Lucy Becker Professor of Medicine in the Stanford School of Medicine, and Forsyth, a research scientist with the School of Medicine, discuss the prevalence of lead-tainted products, and share insights on how food safety policies, education, and lead-free alternatives could reduce the risks.

You call for a complete phase-out of lead by 2035. What do you see as the key hurdles to achieving this goal, especially in countries with limited regulatory enforcement?

Luby: The key hurdles include overcoming the pushback from industries that, like tobacco companies, have a financial incentive in continuing to generate a product that kills millions of people every year. This requires a clear-eyed view of the enormous human and environmental health costs of having lead in the economy.

When we consider the great success of removing chlorofluorocarbons from the atmosphere, the technological innovations in aerosol propellants and in refrigerants occurred in high-income countries within companies that understood that regulation was on the horizon. By the time the Montréal protocol came into force, low-income countries could purchase new-generation propellants in refrigerants that were affordable and did not exert such damage to the Earth's protective ozone layer.

Lead contamination disproportionately affects marginalized communities. What policy interventions or public health measures could ensure that these vulnerable populations are protected?

Luby: Globally, industrial pollution is disproportionately discharged near communities with limited economic and political influence. Efforts to reduce industrial discharges are important, but because lead is so toxic to the environment and human life, the primary public health measure should be to remove it from the economy. This way, the whole web of life, including humans, would benefit.

Forsyth: And since lead does not degrade or go away on its own, remediation of current contaminated sites is a companion endeavor to reduce exposure among the most vulnerable.

Lead chromate in turmeric is a form of food fraud that can have devastating long-term effects. What immediate steps can governments and international organizations take to halt this practice, and how can consumer awareness be raised?

Forsyth: Our experience in Bangladesh suggests that three immediate actions would halt the practice. First is to improve awareness about lead's toxicity. Second is to enhance detection. Often, food safety officers have too many priorities, too little bandwidth, and limited-to-no testing capacity. Finally, enforcing food safety policy is essential: fining sellers of tainted turmeric. Even just enforcing food safety policy once can have a sustained effect.

In your research on lead-acid batteries, you highlight their significant contribution to global lead use. What alternative technologies hold the most promise for replacing lead-acid batteries, and how can these solutions be made accessible to developing nations?

Luby: Currently, lithium-ion batteries are lighter, last longer, and have a lower total cost of ownership than lead acid batteries. They are well placed to immediately replace lead acid batteries in nearly all applications. The best step that low-income countries can take is to remove tariffs on importing lithium-ion batteries so that they can compete against highly polluting lead acid battery industries.

Forsyth: It is likely that improved awareness and financing, such as microfinance loans, will be needed to overcome higher upfront cost of alternatives to lead acid batteries. Because of the broadening electrification of the global energy grid, there is enormous investment in battery technology. In the coming decades, there will be multiple alternatives including sodium-ion, magnesium-iron, and aluminum-iron technologies.

For more information

Research by Luby and Forsyth, initially funded by the Stanford Woods Institute for the Environment and the Stanford King Center on Global Development, identified lead adulteration in turmeric as the primary cause of elevated blood lead levels across rural Bangladesh. Since then, their collaboration with government authorities has led to the implementation of stricter testing and quality control measures in the spice industry, enhancing food safety protocols. Public health initiatives and education campaigns informed by the project have targeted interventions to reduce lead exposure in affected populations and inform people about the risks of lead contamination in spices.

The project's geographical scope has expanded to India and Pakistan, where similar contamination issues have been identified, and its focus has expanded to investigate and address pollution from the lead-acid battery industry. Now called Project Unleaded, the initiative is part of the Stanford Center for Human and Planetary Health. It aims to identify and prioritize the most important sources of lead poisoning globally, investigate health impacts, advance rapid lead detection techniques, and develop, test, and scale up interventions to eliminate major sources of lead contamination.

Luby is also director of research at the Stanford Center for Innovation in Global Health, a senior fellow at the Stanford Woods Institute for the Environment and the Freeman Spogli Institute for International Studies, and a member of Stanford Bio-X and the Stanford Child Health Research Institute. Forsyth is also affiliated with the King Center on Global Development, the Stanford Woods Institute for the Environment, and the Stanford Doerr School of Sustainability.