Researchers at Columbia University’s Mailman School of Public Health found that increased temperatures above 2C and rising carbon dioxide levels lead to higher concentrations of inorganic arsenic in rice.
The study, which was published in The Lancet Planetary Health, also concluded that increased levels of arsenic in rise could potentially raise lifetime health risks for populations in Asia by 2050, as arsenic is highly toxic in its inorganic form.
The combined effects of rising CO2 levels and temperatures on arsenic accumulation in rice had not been studied in detail until this study, which was conducted in conjunction with researchers at John Hopkins Bloomberg School of Public Health and the Chinese Academy of Sciences.
“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 Lewis Ziska, PhD, Columbia Mailman School associate professor of Environmental Health Sciences.
“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.”
Ziska noted that higher arsenic levels are likely the result of changes in soil chemistry induced by climate change.
“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 ischemic heart disease,” he added.
“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.”
Researchers involved in the study measured the effects of rising temperatures and CO2 on 28 rice strains over ten years in the field using Free-Air CO2 Enrichment methodology, before using advanced modelling techniques to project the potential impact on health.
The study’s projections for 2050 suggest a sharp rise in lifetime cancer cases, particularly lung and bladder cancers, in Bangladesh, China, India, Indonesia, Myanmar, the Philippines and Vietnam. China is projected to see the highest number of cases, with an estimated 13.4 million cancers linked to rice-based arsenic exposure.
In response, the researchers called for urgent action to help reduce arsenic exposure in the future, especially as climate change continues to affect global food security.
“These include efforts in plant breeding to minimize arsenic uptake, improved soil management in rice paddies, and better processing practices,” Ziska continued.
“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.”
