Study in Science journal says up to 1.4 billion people at health risk due to toxic soil.
A global team of scientists has issued a stark warning that between 14% and 17% of the world’s arable land is contaminated with at least one type of toxic heavy metal, posing potential health risks to as many as 1.4 billion people.
The findings, published Thursday in the prestigious journal Science, are based on a comprehensive meta-analysis of more than 796,000 soil samples gathered from previous studies, combined with advanced algorithms and artificial intelligence tools. The study presents one of the most detailed global assessments to date of heavy metal contamination in agricultural land.
Led by environmental scientist Deyi Hu of China’s Tsinghua University, the research focused on identifying areas where contamination levels of at least one of seven key metals—such as arsenic, cadmium, lead, or mercury—exceeded internationally recommended thresholds for safe agricultural use and human health.
“These metals are toxic to humans, animals, and plants, even at low concentrations,” the study notes. “They can spread through ecosystems via food chains and water systems, accumulating and amplifying their impact.”
Risk Extends to Nearly 1.4 Billion People
Based on the compiled data and AI-supported projections, the researchers estimate that between 900 million and 1.4 billion people currently live in regions where contaminated soil poses significant health hazards.
The contamination, they say, can stem from both natural geological sources—as many metals occur in varying concentrations in underlying rock—and human activities such as industrial waste disposal, agricultural runoff, and mining operations.
Data Gaps and Urgent Warning
The researchers stressed that their findings may underestimate the true global scale of contamination, particularly in understudied regions like Africa, where reliable data remains scarce.
“The results are insufficient to implement precise risk mitigation policies,” the authors wrote. “But they should serve as a warning to governments, policymakers, and farmers to prioritize soil health monitoring.”
Wakine Negasa, a soil chemist at the James Houghton Institute, who was not involved in the study, echoed the concern, stating: “The true extent of global soil contamination could significantly exceed what the study authors have estimated, because the available data is limited.”
The study calls for more comprehensive monitoring systems and international cooperation to prevent long-term damage to ecosystems and human health.
