Agricultural Land Contaminated by Toxic Heavy Metal Pollution

Syllabus: GS3/ Environment

Context

• A new study has revealed that soil pollution from toxic heavy metals and metalloids is significantly reducing crop yields and contaminating food supplies across the globe.

Key highlights

• The research found that between 14 percent and 17 percent of the world’s agricultural soils (About 242 million hectares) exceed safe thresholds for at least one hazardous metal.
• This contamination affects an estimated 900 million to 1.4 billion people living in high-risk regions.
• A heavily contaminated belt has been identified across low-latitude Eurasia, covering regions like southern Europe, the Middle East, South Asia, and southern China.
• The widespread  contaminants are Cadmium, Arsenic, Cobalt, Nickel and Chromium.

Causes of Heavy Metal Accumulation

• Anthropogenic Causes: Mining, smelting, industrial activities, and intensive agriculture (excessive fertilizer and pesticide use).
• Natural Causes: Metal-rich bedrock and low rainfall in some regions that facilitate pollutant accumulation.

Impact of metal contamination

• Food Chain Contamination: Crops grown in polluted soils absorb heavy metals like cadmium, arsenic, lead, and mercury. These metals enter the human body through food consumption.
• Bioaccumulation: Long-term ingestion of low doses can lead to bioaccumulation, resulting in chronic diseases, including neurological and developmental disorders.
• Biodiversity Loss: Toxic metals harm beneficial organisms like earthworms, insects, and microbes, leading to reduced biodiversity both below and above the soil.
• Land Degradation: Continuous pollution makes soils barren, contributing to land degradation and desertification.

Concerns

• Data Gaps: Limited information from sub-Saharan Africa, northern Russia, and parts of central India may mean the issue is even more widespread.
• Food Trade Risks: Global food trade could transfer contamination to low-risk regions, threatening broader food security.
• Rising Demand for Metals: Increasing industrial demand is likely to worsen the contamination crisis without urgent mitigation measures.

Government Initiatives for Soil Conservation

• Soil Health Card Scheme: It provides farmers with soil nutrient status reports to encourage balanced fertilizer use and improve productivity.
• Promotion of Organic Farming: Initiatives like Paramparagat Krishi Vikas Yojana (PKVY) encourage organic farming practices to maintain soil health.
• National Mission for Sustainable Agriculture (NMSA): It focuses on enhancing soil health through integrated farming systems and agroforestry practices.

Global Initiatives

• Global Soil Partnership (GSP): It is an FAO-led initiative to improve global soil governance and promote sustainable soil management.
• United Nations Convention to Combat Desertification (UNCCD): It works to prevent land degradation and promote sustainable land management globally.
  • It has a pledge for land degradation neutrality (LDN) by 2030. 
• 4 per 1000 Initiative: It aims to increase soil carbon stocks by 0.4% annually to combat climate change and enhance soil health.

Way Ahead

• Establish regional soil health observatories and expand the coverage of soil surveys.
• Phytoremediation: Use of hyperaccumulator plants and microbes to clean contaminated soils.
• Circular Economy: Recycling and management of e-waste, industrial waste to prevent soil contamination.
• Farmer Awareness Programs: Educate farmers on heavy metal risks, safe agricultural practices, and alternative cropping systems.

Source: DTE