ARSENIC LEVELS IN RICE: SCIENCE & TECHNOLOGY

NEWS: Study links climate change with rising arsenic levels in rice, increasing cancer risks for Asians

WHAT’S IN THE NEWS?

A Lancet Planetary Health study warns that rising temperatures and CO₂ levels from climate change could significantly increase arsenic accumulation in rice by 2050, especially affecting South and Southeast Asia. This could lead to millions of new cancer cases and serious public health challenges unless urgent mitigation efforts are undertaken.

Context

  • A new study published in The Lancet Planetary Health has found that climate change, particularly the rise in global temperatures and carbon dioxide (CO₂) levels, could cause a significant increase in arsenic levels in rice by the year 2050.
  • These environmental changes are altering soil chemistry, making it easier for arsenic present in the soil and groundwater to be absorbed by rice plants.

Health Implications of Elevated Arsenic

  • Serious Cancer Risks:
  • Consumption of arsenic-contaminated rice will likely increase the incidence of several types of cancers.
  • Cancers of the lung, bladder, and skin are projected to become significantly more common among populations that consume rice as a staple food.
  • Non-Cancer Health Effects:
  • Elevated arsenic exposure is not limited to cancer; it also contributes to:
      • Cardiovascular diseases such as heart disease.
      • Metabolic disorders like diabetes.
      • Neurodevelopmental disorders in children, affecting brain growth and cognitive function.
      • Pregnancy-related complications, including higher risks of miscarriage, stillbirth, and low birth weight.

Widespread Risk in Asia

  • Regional Vulnerability:
  • The impact will be especially severe in South Asia and Southeast Asia, where rice forms a fundamental part of the daily diet for billions of people.
  • Highly Vulnerable Countries:
  • India, Bangladesh, China, and Vietnam are particularly at risk due to:
      • High per capita rice consumption.
      • Pre-existing problems of arsenic contamination in groundwater.
  • Projected Health Crisis:
  • The study warns that if the trend continues, tens of millions of new cancer cases could arise by 2050.
  • China alone could see over 13 million new cancer cases due to arsenic exposure through rice consumption.

Scientific Basis and Methodology

  • Long-Term Field Tests:
  • Researchers conducted extensive field studies over a decade, testing 28 different rice strains to observe how they absorbed arsenic under changing climate conditions.
  • Modeling Future Risks:
  • They combined experimental data with predictive modeling to estimate how climate change will alter arsenic levels in rice across seven major rice-consuming Asian countries.
  • Key Findings:
  • Synergistic Effect: It was observed that higher temperatures and increased atmospheric CO₂ levels together dramatically boost arsenic accumulation in rice plants compared to either factor alone.
  • Soil Chemistry Changes: Rising CO₂ alters soil microbial activities and chemical properties, enhancing arsenic mobilization and plant uptake.

Mitigation and Policy Recommendations

  • Development of New Rice Varieties:
  • Focus on breeding and cultivating low-arsenic rice varieties that have a reduced tendency to absorb arsenic from soil and water.
  • Improved Soil and Water Management:
  • Introduce agricultural practices that lower arsenic availability in paddy fields, such as:
      • Controlled irrigation techniques (e.g., alternating wetting and drying of fields).
      • Using soil amendments that immobilize arsenic.
  • Public Health Campaigns:
  • Launch awareness programs aimed at:
      • Educating farmers and consumers about the dangers of arsenic.
      • Promoting diversification of diet to reduce heavy dependence on rice alone.
      • Encouraging regular monitoring of arsenic levels in agricultural zones.
  • Policy Interventions:
  • Governments must prioritize arsenic mitigation strategies in their climate adaptation and food security policies.
  • International cooperation may be necessary, given the transboundary nature of food trade and environmental change.

Source: https://www.thehindu.com/sci-tech/health/study-links-climate-change-with-rising-arsenic-levels-in-rice-increasing-cancer-risks-for-asians/article69474056.ece