Rising CO2 and heat may spike arsenic in rice, warns Columbia University study on Asia’s looming health crisis
The study is the first to deeply examine how the combination of elevated carbon dioxide and warming above 2°C affects arsenic buildup in rice.
- Apr 17, 2025,
- Updated Apr 17, 2025 3:47 PM IST
As climate change intensifies, the humble bowl of rice may carry an unexpected risk. A groundbreaking study from Columbia University's Mailman School of Public Health reveals that rising global temperatures and CO2 levels could significantly boost the concentration of toxic arsenic in paddy rice, a dietary staple for billions. By 2050, this shift could sharply increase lifetime health risks, particularly across Asia, where rice is consumed most heavily.
The study is the first to deeply examine how the combination of elevated carbon dioxide and warming above 2°C affects arsenic buildup in rice. Researchers from Columbia, Johns Hopkins Bloomberg School of Public Health, and the Chinese Academy of Sciences published their findings in The Lancet Planetary Health.
“Our results suggest that this increase in arsenic levels could significantly elevate the incidence of heart disease, diabetes, and other non-cancer health effects,” Lewis Ziska, PhD, associate professor of Environmental Health Sciences at Columbia Mailman School, told phys.org. “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.”
According to Ziska, the spike in arsenic concentrations is likely driven by climate-induced changes in soil chemistry, which make arsenic more bioavailable and easier for rice plants to absorb.
“From a health perspective, the toxicological effects of chronic iAs exposure are well established, and include cancers of the lung, bladder, and skin, as well as ischemic heart disease,” he said, adding “Emerging evidence also suggests that arsenic exposure may be linked to diabetes, adverse pregnancy outcomes, neurodevelopmental issues, and immune system effects.”
This threat is far from theoretical. “Ingesting rice in regions like southern China and Southeast and South Asia is already a significant source of dietary arsenic and cancer risk,” Ziska added.
To assess future risks, researchers examined the impact of rising temperatures and CO2 on 28 rice strains over a decade using FACE (Free-Air CO2 Enrichment) field studies. They then modeled health outcomes for seven Asian countries: Bangladesh, China, India, Indonesia, Myanmar, the Philippines and Vietnam.
The analysis factored in 2021 country-specific rice consumption from FAO food balance sheets and applied EPA-derived bodyweight-adjusted ingestion distributions. The resulting projections paint a troubling picture for 2050.
Among the most alarming findings: China could face 13.4 million additional cancer cases due to rice-based arsenic exposure, with lung and bladder cancers leading the toll.
“Based on our findings, we believe there are several actions that could help reduce arsenic exposure in the future,” said Ziska.
As climate change intensifies, the humble bowl of rice may carry an unexpected risk. A groundbreaking study from Columbia University's Mailman School of Public Health reveals that rising global temperatures and CO2 levels could significantly boost the concentration of toxic arsenic in paddy rice, a dietary staple for billions. By 2050, this shift could sharply increase lifetime health risks, particularly across Asia, where rice is consumed most heavily.
The study is the first to deeply examine how the combination of elevated carbon dioxide and warming above 2°C affects arsenic buildup in rice. Researchers from Columbia, Johns Hopkins Bloomberg School of Public Health, and the Chinese Academy of Sciences published their findings in The Lancet Planetary Health.
“Our results suggest that this increase in arsenic levels could significantly elevate the incidence of heart disease, diabetes, and other non-cancer health effects,” Lewis Ziska, PhD, associate professor of Environmental Health Sciences at Columbia Mailman School, told phys.org. “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.”
According to Ziska, the spike in arsenic concentrations is likely driven by climate-induced changes in soil chemistry, which make arsenic more bioavailable and easier for rice plants to absorb.
“From a health perspective, the toxicological effects of chronic iAs exposure are well established, and include cancers of the lung, bladder, and skin, as well as ischemic heart disease,” he said, adding “Emerging evidence also suggests that arsenic exposure may be linked to diabetes, adverse pregnancy outcomes, neurodevelopmental issues, and immune system effects.”
This threat is far from theoretical. “Ingesting rice in regions like southern China and Southeast and South Asia is already a significant source of dietary arsenic and cancer risk,” Ziska added.
To assess future risks, researchers examined the impact of rising temperatures and CO2 on 28 rice strains over a decade using FACE (Free-Air CO2 Enrichment) field studies. They then modeled health outcomes for seven Asian countries: Bangladesh, China, India, Indonesia, Myanmar, the Philippines and Vietnam.
The analysis factored in 2021 country-specific rice consumption from FAO food balance sheets and applied EPA-derived bodyweight-adjusted ingestion distributions. The resulting projections paint a troubling picture for 2050.
Among the most alarming findings: China could face 13.4 million additional cancer cases due to rice-based arsenic exposure, with lung and bladder cancers leading the toll.
“Based on our findings, we believe there are several actions that could help reduce arsenic exposure in the future,” said Ziska.