Washington. Of the total world of global cultivation, 17 percent are contaminated by toxic heavy metals, a fact that represents a risk for ecosystems and human health, highlights a study released today in Science.
About 1,400 million people live in areas where the soil contains metals at harmful levels for human health and ecosystems, such as arsenic, cadmium, cobalt, chromium, copper, nickel and lead, says the international study led by the University of Tsinghua in China.
Pollution of the soil by heavy metals has its origin in both natural sources and in human activities and represents a risk for ecosystems and human health, the article points out.
Some of the consequences of the presence of these metals on the ground are that they persist for decades, reduce agricultural yields, put water, biodiversity and food safety at risk due to bioaccumulation in farm animals, the study points out.
The investigation evaluated the contamination produced worldwide by seven metals: arsenic, cadmium, cobalt, chromium, copper, nickel and lead.
Of these, cadmium is the most dangerous for human health because it affects the greatest surface and is a potential carcinogen, in addition to being associated with other ailments, the authors underline.
To reach these results, the researchers explored the performance of 10 automatic learning models that calculate the presence in excess of toxic metals, according to a series of predictive variables.
Their estimates suggest that between 14 and 17 percent of the cultivation lands worldwide – approximately 242 million hectares – are contaminated by at least one toxic metal, the cadmium being the most widespread, especially in the south and east of Asia, parts of the Middle East and Africa.