A person’s hands cup a sample of pelletized agricultural fertlizer and a piece of the phosphate rock from which it is created. Credit: Robert Hill, Duke University
An international team of scientists has uncovered toxic metals in mineral phosphate fertilizers worldwide by using a new tool to identify the spread and impact of such contaminants on soil, water resources, and food supply.
“While mineral phosphate fertilizers are critical to boost global sustainable agriculture and food security, we found high levels of toxic metals in many fertilizers worldwide,” said Avner Vengosh, chair of the Earth and Climate Sciences division at Duke University’s Nicholas School of the Environment.
“Our study developed a new method to identify sources and impacts of these metals on the environment.” Those metals included cadmium, uranium, arsenic, vanadium, and chromium.
Use of mineral fertilizer—synthetic or naturally occurring substances with essential nutrients needed for plant growth—has helped boost sustainable crop yields worldwide. But until recently, its contamination with toxic metals has not been systematically evaluated. This new study analyzes global phosphate fertilizers from major phosphate-mining countries.
“We measured strontium isotopes in both phosphate rocks and fertilizers generated from those rocks to show how fertilizers’ isotope ‘fingerprint’ matches their original source,” said Robert Hill, the study’s lead author and a Ph.D. student at Duke University.
Isotopes are variations of an element, in this case strontium. Chemical analysis of each fertilizer shows a unique isotope mix that matches phosphate rocks from where it was sourced.
2024-05-17 16:51:02
Post from phys.org
