Tungsten is thought to be an environment friendly metal. But now, scientists have cast doubts on its safety.
The metal is widely used in products ranging from bullets to light bulbs to jewellery.
According to C and EN Associate Editor Rachel Petkewich, scientists have long held that tungsten is relatively insoluble in water and nontoxic.
The U.S. military, had in mid-1990s developed, the so-called "green bullets" that contain tungsten as a more environmentally friendly alternative to lead-based ammunition.
However, new studies have now show that tungsten, which is also used in welding, metal cutting, and other applications, is not as chemically inert as thought.
It has been shown that exposure to tungsten can stunt the growth of plants, cause reproductive problems in earthworms, and trigger premature death in certain aquatic animals
Both the U.S. Department of Defence and the Environmental Protection Agency have also classified the element as an "emerging contaminant" of concern.
In the article, Petkewich said that although scientists think that tungsten seems much less toxic than lead or mercury, they do not know its exact health and environmental effects.
However, whether or not tungsten can cause chronic health effects in humans, and its mechanism of action, awaits further study, said Petkewich.
The article appears in Chemical and Engineering News, ACS' weekly newsmagazine.