New Delhi: As climate change accelerates, new findings suggest that higher temperatures and rising carbon dioxide levels could significantly increase arsenic levels in rice, a staple food for millions in Asia.
A study from Columbia University Mailman School of Public Health, published in The Lancet Planetary Health, shows that these environmental changes could elevate inorganic arsenic in rice, leading to serious health risks such as heart disease, diabetes, and cancer by 2050.
The research, conducted with Johns Hopkins Bloomberg School of Public Health and the Chinese Academy of Sciences, is the first to explore how rising temperatures and CO₂ interact to influence arsenic accumulation in rice.
“Our results suggest that this increase in arsenic levels could significantly elevate the incidence of heart disease, diabetes, and other non-cancer health effects,” said Dr. Lewis Ziska, Associate Professor of Environmental Health Sciences at Columbia Mailman School. “As rice is a dietary staple in many parts of the world, these changes could lead to a substantial rise in the global burden of cancer, cardiovascular diseases, and other arsenic-related health issues.”
Dr. Ziska explained that climate change, through rising CO₂ levels and temperatures, alters the soil microbiome, leading to higher arsenic uptake in rice plants.
“From a health perspective, the toxicological effects of chronic arsenic exposure are well established and include cancers of the lung, bladder, and skin, as well as ischaemic heart disease,” he said. “Emerging evidence also suggests that arsenic exposure may be linked to diabetes, adverse pregnancy outcomes, neurodevelopmental issues, and immune system effects. In fact, ingesting rice in regions like southern China and Southeast and South Asia is already a significant source of dietary arsenic and cancer risk.”
The study analysed the impact of increasing temperature and CO₂ on 28 rice strains over a 10-year period using Free-Air CO₂ Enrichment (FACE) methodology.
The team then combined this data with advanced modelling techniques to estimate inorganic arsenic doses and health risks for seven Asian countries: Bangladesh, China, India, Indonesia, Myanmar, the Philippines, and Vietnam.
Projections for 2050 suggest a significant rise in cancer cases, particularly lung and bladder cancers. China is expected to face the highest number, with an estimated 13.4 million cancer cases linked to rice-based arsenic exposure.
“Based on our findings, we believe there are several actions that could help reduce arsenic exposure in the future,” Dr. Ziska stated. “These include efforts in plant breeding to minimize arsenic uptake, improved soil management in rice paddies, and better processing practices. Such measures, along with public health initiatives focused on consumer education and exposure monitoring, could play a critical role in mitigating the health impacts of climate change on rice consumption.”
“Our study underscores the urgent need for action to reduce arsenic exposure in rice, especially as climate change continues to affect global food security,” he added.