A new study has found that rising temperatures and increasing carbon dioxide (CO₂) levels are causing rice to absorb higher amounts of arsenic, making it significantly more toxic and potentially dangerous.
If this trend continues, scientists warn that rice, a staple food for billions of people, could become poisonous in the future.
The research, led by Columbia University and published in The Lancet Planetary Health, shows that warmer, carbon-rich conditions increase the concentration of inorganic arsenic in rice.
Why Arsenic In Rice Is A Major Health Risk
Arsenic is a naturally occurring element found in groundwater, and once it enters the human body through food, it can trigger serious health problems.
Inorganic arsenic is highly toxic. Long-term exposure has been linked to heart disease, diabetes, and several forms of cancer. Once absorbed through rice consumption, it accumulates in the body, increasing the risk of chronic illnesses over time.
What The Study Found In China’s Rice Fields
Scientists studied rice cultivation in the Yangtze River Delta in China for more than a decade. Their findings revealed that higher temperatures and elevated CO₂ levels are altering the way rice grows, mainly by changing soil chemistry.
Flooded rice paddies make arsenic more soluble in soil and groundwater. As a result, rice absorbs 10 to 20 times more arsenic than other crops, making it particularly vulnerable to contamination.
A Growing Threat Across Asia
This is not just a problem for China. Similar risks are emerging across Asia, including Bangladesh, India, Indonesia, Myanmar, the Philippines, and Vietnam. Researchers warn that if greenhouse gas emissions continue at current levels, arsenic concentrations in rice could reach dangerous thresholds by 2050.
- In China, an estimated 19.3 million cancer cases are expected by 2050.
- In polluted regions of India, such as Chhattisgarh, the problem is already severe.
- Vietnam and Indonesia are considered the most at risk, with projections showing the highest arsenic levels.
These conditions could lead to a sharp rise in lung, skin, and bladder cancers, along with an increased risk of brain disorders in children.
How Can This Crisis Be Prevented?
Reducing global greenhouse gas emissions remains the most effective solution. However, scientists also suggest several immediate measures:
- Developing new rice varieties that naturally block arsenic accumulation
- Choosing basmati rice, which contains lower arsenic levels
- Avoiding brown rice, which tends to retain more arsenic
- Washing rice thoroughly and boiling it in plenty of water before consumption
Other Crops Are Also At Risk
Air pollution and rising CO₂ levels will not make wheat, pulses, or vegetables completely poisonous, but they are expected to lose nutritional value. In some cases, harmful elements may increase, posing health risks.
High CO₂ levels can raise toxic elements such as lead in crops, which is especially dangerous for children and pregnant women. Although these foods may remain edible, nutrient imbalances could worsen malnutrition, particularly in regions heavily dependent on grains.
In polluted countries like India, wheat and pulses are expected to be among the most affected, as pollution reduces plants’ ability to absorb nutrients.
Nutritional Decline In Staple Foods
Research from Harvard University shows that rising CO₂ levels could reduce protein, iron, and zinc in wheat, rice, and barley by 5 to 15%. Scientists believe maize will be hit the hardest, with yields falling sharply as temperatures rise.
Fruits and vegetables of the future may also be less nutritious than those grown today.
Climate-Resilient Foods Offer Hope
Certain crops show strong resistance to climate change:
- Millets such as bajra, jowar, and ragi, often called superfoods and smart crops, require less water, tolerate higher temperatures, and remain rich in iron, calcium, and magnesium, even under rising CO₂ levels.
- Pulses like chickpeas, mung beans, and pigeon peas enrich soil by fixing nitrogen from the air, reducing the need for chemical fertilisers. Their deep roots help them survive drought conditions.
- Sea grass could become a major future food source. It absorbs CO₂ far faster than land trees, requires no land or fresh water, and is rich in vitamins and omega-3 fatty acids.
- Sweet potatoes, often described as disaster-saving crops, grow underground and are protected from storms and cyclones. They are rich in vitamin A and play a vital role in fighting malnutrition.
