People are being exposed to tiny silver particles that could poison them, particularly children.
Darin Furgeson, professor of pharmaceutical chemistry, in collaboration with Joe Yost, professor of neurobiology and anatomy and Ed Clark, professor and chairman of pediatrics, is studying how nanoparticles affect people and future generations.
Nanoparticles are any heavy metal, such as mercury and uranium. Once they enter a person’s system, it is unclear how long they take to leave, if they do at all, Furgeson said.
Silver nanoparticles have become increasingly popular to use in commercial items, he said. Companies have been adding them to shoes and clothes to fight body odor, he said. They can also be found in laundry detergent and are used to purify water. Because of this, silver nanoparticles are being added to groundwater, making it easier for children to be exposed to the toxins, he said.
The main concern for Furgeson is how children will be affected. Although adults might not show any signs from the toxins, studies have shown that their grandchildren will have increased cases of cancer, diabetes and other conditions, he said.
Researchers hope they will be able to better identify the toxin earlier, find it in the environment and prevent further damage, Furgeson said.
“Children are much more sensitive to toxic events because they are early in development,” he said. “Even more sensitive can be a pregnant woman. Children are our future. We have to protect them. They cannot protect themselves.”
Researchers don’t understand how the tiny silver particles will affect children yet, but they’ve tested zebrafish as an early phase of finding out. Many of the fish had tail malformations and fluid sacs around their hearts, which caused their bodies and organs to be starved of oxygen, and some died, Furgeson said.
Furgeson tested zebrafish because they have been well-established in the scientific world as a good organism on which to perform research testing. They are transparent, so researchers can easily view where cells have died because the area on the fish will be opaque, he said.
Zebrafish also have similar genomes8212;80 to 85 percent of their genome is similar to humans, he said. They also have many of the organs humans do, such as the heart, liver, kidneys and spleen. However, since they use gills to breathe, they do not have lungs, Furgeson said.
“This is very important,” he said. “When it comes to pharmaceutics, the four primary organs that we are worried about are the lungs, the spleen, the liver and the kidneys, because those are the sites that we see toxicity that is induced by drugs.”
Four hours after fertilization, Furgeson and his team of researchers introduced the zebrafish embryos to varying amounts of silver and gold nanoparticles, respectively, only changing the size and concentration, he said. After continuous exposure for five days, they looked at the differences caused by the particles.
They exposed the zebrafish to gold nanoparticles to see what effect the similar metal might have, because the ancient Egyptians used to drink gold elixirs to promote health, vitality and immortality, Furgeson said. There have been no negative side effects shown in relation to the exposure to gold, he said.
Furgeson created a test to compare the results from the different sizes of the nanoparticles. He then ranked the zebrafish on a scale of zero to four8212;at zero, the fish had no physical deformities, and four meant the fish died. Furgeson gave the fish a ranking depending on the severity of visible physical abnormalities, such as enlarged eyes and fluid around the heart, he said.
The fish that had been exposed to gold nanoparticles showed little to no visible deformations, and those that had been exposed to silver did.
“It confirmed our belief that physical and chemical parameters can affect toxicity (such as) size, surface charge, shape,” Furgeson said.
Furgeson said he fears that people will not understand the full effects of what exposure to silver nanoparticles will do, and that it will be too late before they can do anything about it. Although researchers can see that the zebrafish have physical abnormalities, they do not know how it will affect future generations of humans, he said.
“This is an area that is really, really untouched,” Furgeson said. “Nanotoxicology is a waking giant in a field of research.”