22/4/2025
Almost a fifth of world’s acreage is polluted by dangerous residues at levels up to 10% higher than the safety limit for farming
April 17, 2025
Farmlands in the Middle East and East Africa have some of the world’s highest levels of toxic metals, including nitrogen and chromium contaminants, in their soil, a study has found.
Metals are naturally released into soil, but mining has led to excessive toxic deposits in some parts of the world, making the soil less fertile and food crops unsafe.
The UN’s Food and Agriculture Organisation has warned that 90 per cent of global soil resources may be at risk by 2050, owing to soil erosion, excessive use of fertilisers and pesticides, and industrial pollution.
But researchers at the University of Tsinghua in Beijing, China, fear that the impact of toxic metals in this mix is being overlooked.
Up to 17 per cent of croplands globally were polluted by an excess of toxic metals, putting 0.9 and 1.4 billion people at risk of health issues and climate-related dangers, according to their study, which was published in the peer-reviewed journal Science.
The risks are compounded by the fact that food production needs to increase by 35 per cent to 56 per cent by 2050 as the human population continues to grow.
In the Middle East, scientists found an excess of chromium and nitrogen of up to 5.8 per cent. These metals were also prevalent to the same levels in East Africa and southern Russia.
The most widely spread toxic metal was cadmium, which was found at 10 percentage points over the safety limit for farming in north and central India, Pakistan and Bangladesh, Southern Thailand and Cambodia, Iran, Turkey, Ethiopia, Nigeria and South Africa.
Viewed together, many of the affected regions coincide with places where the world’s earliest civilisations thrived, such as ancient Greece and Rome, Mesopotamia, Persia, India and the Chinese cultures of the Yangtze River.
The scientists suggest that this belt, which is often referred to as the Silk Road because of its historic trade routes, is where the Anthropocene – the era when human activity began to influence nature and the climate – began.
“We reveal a previously unrecognised high-risk, metal-enriched zone in low-latitude Eurasia, which is attributed to influential climatic, topographic and anthropogenic conditions. This feature can be regarded as a signpost for the Anthropocene era,” the scientists wrote.