A major international study warns that rising temperatures and higher atmospheric carbon dioxide are increasing arsenic concentrations in rice, Thailand’s everyday staple. The findings, published in The Lancet Planetary Health, suggest that climate change could turn rice into a greater health risk for populations that rely on it for most of their daily calories. This issue resonates across rice-dependent societies, including Thailand, where consumption is deeply tied to culture and livelihood.
Rice is described as the planet’s most important staple crop, with half of humanity relying on it for the majority of their calories. The new multi-year study led by a team including researchers from Columbia University examined how future climate scenarios might affect rice safety. Unlike prior work that looked at CO₂ or heat in isolation, this project tested both factors together across a range of rice varieties, reflecting conditions expected as the climate warms.
When crops were grown under simulated future climates—higher CO₂ and higher temperatures—the arsenic levels in rice grains rose markedly. “Previously we saw responses to individual stressors, but combining them produced an effect we did not anticipate,” said a lead researcher. The results indicate a toxicological risk that escalates with climate pressures. Thailand, a country where rice is central to meals and economic activity, could face heightened exposure and health concerns.
The risk begins in the paddy fields. Rice is typically grown in flooded fields, which helps control weeds and creates the fragrant grains Thai cuisine is known for, from jasmine rice to sticky rice. However, the flooded environment also allows arsenic to be absorbed from natural sources and pollution. Higher heat and CO₂ alter soil chemistry, increasing the availability of inorganic arsenic—the more harmful form—and its uptake by rice plants.
Long-term exposure to inorganic arsenic is linked to higher risks of cancers, heart disease, and neurological effects, particularly in infants. Public health experts urge vigilance as climate change could compound these risks. Data from multiple Asian rice-consuming countries show a consistent pattern: higher arsenic in diets translates to elevated disease risk. Given Thailand’s high rice consumption and agriculture, the Thai population faces similar vulnerabilities.
Culturally and economically, Thailand is tightly linked to rice. The grain underpins export earnings and daily life, including rituals of blessing new plantings and everyday meals that feature both jasmine rice and desserts made with rice. Regulatory authorities in Europe and North America have issued arsenic guidelines for rice products, especially for infants. In the United States, federal limits for arsenic in foods remain a work in progress, while in Thailand the priority is to monitor quality amid a large domestic market and a multi-billion-baht export sector.
Thai experts emphasize the need for practical responses. A Thai food safety scientist not affiliated with the study urged closer collaboration between health agencies and agricultural researchers to establish routine arsenic testing in rice and to adapt farming practices as temperatures rise. Public demand for safe sourcing and transparent certifications could help drive change.
Historically, concerns about arsenic in Thai rice have surfaced in regions with high natural arsenic in soil or groundwater. The new research, however, shows that climate change itself can magnify risk even in areas with lower baseline contamination. This finding challenges policymakers at the Ministry of Agriculture and Cooperatives and the Food and Drug Administration to consider broader testing, accelerated development of low-arsenic rice varieties, and stronger monitoring across the supply chain.
Experts recommend a three-pronged approach: accelerate breeding of low-arsenic rice, optimize water and field management to limit arsenic uptake, and expand public education about dietary diversification, especially for children and pregnant people. “The primary step is to act decisively to slow climate change and reduce exposures where possible,” one researcher stressed.
For Thai readers, practical steps include staying informed about rice quality, especially for products marketed as organic or sourced from regions with groundwater concerns. Rinsing rice thoroughly and cooking with ample water that is later discarded can reduce arsenic exposure by a substantial margin. Consumers can also seek information about safe sourcing and certification schemes and advocate for expanded national monitoring. Individual actions, alongside policy measures to curb emissions, can help protect health while sustaining Thailand’s rice-based culture.
Rice remains a symbol of Thai heritage and a cornerstone of the economy. As climate change reshapes its safety profile, informed choices, robust testing, and continued innovation will be essential to protecting public health and preserving a vital national staple.