Toxic heavy metal and metalloid contamination of soil is significantly reducing crop yields and contaminating food supplies around the world

Key Findings The study revealed that approximately 14 to 17 percent of global agricultural soils, equating to around 242 million hectares, surpass safe limits for at least one hazardous metal. This pollution poses a risk to an estimated 900 million to 1.4 billion individuals residing in high-risk areas. A significantly contaminated zone has been identified across low-latitude Eurasia, encompassing regions such as southern Europe, the Middle East, South Asia, and southern China.

The prevalent contaminants include Cadmium, Arsenic, Cobalt, Nickel, and Chromium. Factors Contributing to Heavy Metal Accumulation Human Activities: Mining, smelting, industrial processes, and intensive agricultural practices (including excessive use of fertilizers and pesticides).

Natural Factors: Metal-rich geological formations and low precipitation in certain areas that promote the accumulation of pollutants. Consequences of Metal Contamination Contamination of the Food Chain: Crops cultivated in contaminated soils absorb heavy metals such as cadmium, arsenic, lead, and mercury, which subsequently enter the human body through dietary intake.

Bioaccumulation: Prolonged consumption of low levels of these metals can lead to bioaccumulation, resulting in chronic health issues, including neurological and developmental disorders. Loss of Biodiversity: Toxic metals adversely affect beneficial organisms such as earthworms, insects, and microbes, leading to a decline in biodiversity both in the soil and above it. Land Degradation: Ongoing pollution renders soils infertile, contributing to land degradation and desertification.

Issues of Concern: Data deficiencies in sub-Saharan Africa, northern Russia, and certain regions of central India may indicate a more extensive problem. Risks in Food Trade: The global food trade could inadvertently spread contamination to areas with lower risk, jeopardizing overall food security.

Escalating Metal Demand: The growing industrial need for metals is likely to exacerbate the contamination crisis unless immediate mitigation strategies are implemented. Government Efforts for Soil Conservation: The Soil Health Card Scheme offers farmers insights into soil nutrient levels to promote balanced fertilizer application and enhance productivity.

The promotion of organic farming through initiatives such as the Paramparagat Krishi Vikas Yojana (PKVY) supports practices that sustain soil health. The National Mission for Sustainable Agriculture (NMSA) aims to improve soil health via integrated farming systems and agroforestry. Global Efforts: The Global Soil Partnership (GSP), led by the FAO, seeks to enhance global soil governance and advocate for sustainable soil management.

The United Nations Convention to Combat Desertification (UNCCD) is dedicated to preventing land degradation and fostering sustainable land management worldwide, with a commitment to achieving land degradation neutrality (LDN) by 2030. The 4 per 1000 Initiative aspires to boost soil carbon stocks by 0.4% each year to address climate change and improve soil health. Future Directions:

The establishment of regional soil health observatories and the expansion of soil survey coverage are essential. Phytoremediation involves utilizing hyperaccumulator plants and microbes to remediate contaminated soils.

A circular economy approach focuses on recycling and managing e-waste and industrial waste to avert soil contamination. Additionally, farmer awareness programs are crucial for educating farmers about heavy metal hazards, safe agricultural practices, and alternative cropping systems.