“In Montana, we are finding that nanoparticles are important in transporting toxic heavy metals, such as lead and arsenic, down the river,” said Hochella. “These particles are incredibly small – 5 to 10 nanometers. Historically, we have not even known the nanoparticles were there. Now we know that lead in solution is different than if it is attached to a particle. But finding the particles is not easy. And impact on bioavailability is still unknown.”

He asks, “Are the metals less toxic if they are associated with nanoparticles than if dissolved as atoms in water? If a person, animal, fish, or insect ingests th