A recent study from Columbia University’s Mailman School of Public Health has revealed concerning links between climate change and increased arsenic levels in paddy rice, a staple food for millions across Asia. This research suggests that rising temperatures and increased carbon dioxide (CO2) levels are contributing to higher concentrations of inorganic arsenic (iAs) in rice, which could pose significant health risks, particularly in Asia, by 2050.
The study highlights a critical issue that has previously gone unexamined—how climate-related factors such as higher temperatures and CO2 levels are influencing arsenic accumulation in rice. Arsenic, a known carcinogen, has long been a public health concern due to its association with various health problems, including lung, bladder, and skin cancer, as well as heart disease. Researchers at Columbia, Johns Hopkins Bloomberg School of Public Health, and the Chinese Academy of Sciences conducted field studies and used advanced modeling techniques to assess the potential health risks posed by higher arsenic levels in rice.
According to Dr. Lewis Ziska, associate professor of Environmental Health Sciences at Columbia’s Mailman School, the research suggests that climate-related changes in soil chemistry may be increasing the amount of arsenic that rice plants absorb. As a result, populations in countries such as Bangladesh, China, India, and Vietnam could face a significant rise in health issues related to arsenic exposure, including heart disease, diabetes, and other non-cancerous diseases.
Using the Free-Air CO2 Enrichment (FACE) methodology, the research team studied the effects of elevated CO2 levels and temperatures on 28 rice strains over ten years. They also modeled the potential health risks for seven Asian countries, considering rice consumption rates and estimated arsenic exposure. The study’s projections for 2050 suggest a dramatic increase in lifetime cancer cases, particularly lung and bladder cancers. China is expected to see the highest number of cases, with an estimated 13.4 million cancers linked to rice-based arsenic exposure.
In response to these findings, Dr. Ziska emphasizes the importance of mitigation strategies. “There are several actions that could reduce arsenic exposure, including plant breeding to minimize arsenic uptake, better soil management, and improved rice processing practices,” he said. Public health initiatives focused on consumer education and exposure monitoring could also play a significant role in curbing the impact of rising arsenic levels.
The study underlines the urgent need to address the intersection of climate change and food security. With climate change continuing to affect agricultural practices worldwide, experts call for greater awareness and action to protect vulnerable populations from the health risks posed by contaminated rice.
The full study, titled “Impact of Climate Change on Arsenic Concentrations in Paddy Rice and the Associated Dietary Health Risks in Asia,” was published in The Lancet Planetary Health in April 2025.
