Narrator: This is Science Today. Green rust is a naturally occurring iron oxide in sediments and soil which has been found to convert a toxic form of selenium into a safer form. Researcher Satish Myneni of the Lawrence Berkeley National Laboratory, made the discovery.
Myneni: Basically what happens is, if you have selenium in sediment and if green rust is also present in the same samples and selenium will react with this surface of green rust and then convert it to a very less toxic form called elemental selenium.
Narrator: While selenium is an essential trace mineral present in several foods, Myneni says in high concentrations, it can be highly toxic to humans and wildlife.
Myneni: The main problem is, we don't know exactly at what concentration it converts from a good one to a bad one and I think a lot of people are still doing research on these aspects and we still don't much about that.
Narrator: It used to be thought only bacteria could convert selenium to a safer form, so Myneni's study offers more insight into geochemistry. For Science Today, I'm Larissa Branin.