written by Anna Varela | animation by William Davis | art direction by Basil Iskandrian
Nanotechnology is all around us
Silently helping our clothes resist stains, allowing spray-on sunscreen to more easily protect our skin and enhancing paints, coatings and plastics. Nanoparticles have even made their way into our food, including powdered sugar on pastries, chewing gum and other products.
Christa Wright, assistant professor of environmental health in the Georgia State School of Public Health, researches the potential health impacts of nanoparticles, which can also be found in such everyday items as cosmetics, the toner in photocopiers and artificial turf.
Nanoparticles can’t be seen with the eye or even with a microscope. For a sense of perspective, consider the diameter of a strand of human hair. That cross section of hair is the size of 100,000 nanometers. (A nanometer is a billionth of a meter.)
Wright is among a pioneering group of scientists raising concerns about these super tiny particles. While many nanomaterials start out as substances that are considered safe at normal size, there has been very little testing into how safe these particles are when they are made so small they can travel easily from the lungs into other parts of the body, even slipping into cells and potentially causing damage to DNA.
That means the titanium dioxide that is safe when you smear it on your nose as a sunblock could be dangerous when it is broken down into super tiny bits that can interact with the human body at a cellular level.
The impact could be greater for populations that are already vulnerable, such as people with inherited disorders, especially with long-term exposure.
In one study, Wright found that certain metal-based engineered nanoparticles, widely used in cosmetics and sunscreens such as zinc oxide, could cause DNA damage in human cells.
People who work in the recycling and waste disposal industries may also face an increased risk due to exposure to nanomaterials.
In a recent study, Wright found that high-temperature incineration, a common disposal method for thermoplastics that contain nanoparticles, can result in a “nanofiller effect” where higher toxicity was observed in the particles released during burning of nano-enabled plastics than particles emitted from burned regular materials (plastics containing no nanomaterials).
About 20,000 metric tons of “nanocomposite” materials (such as vinyl siding) are sent to U.S. recycling facilities, landfills or disposed of through incineration each year.
As with products sold directly to consumers, there is no requirement that these materials be labeled and no guidelines for safe disposal of nano-enabled products.
“We’re not trying to demonize any particular material,” Wright said. “There are numerous benefits of nanomaterials across various industrial and research sectors. However, by understanding the material properties and how they behave in biological systems, we can minimize adverse human health outcomes while capitalizing on their unique properties, thereby increasing sustainability of the nanotechnology industry.”
Georgia State Featured Researcher
Dr. Watson-Wright holds a Ph.D. in energy and environmental systems from North Carolina Agricultural and Technical State University. Prior to joining the faculty at Georgia State, she was a lecturer and postdoctoral research fellow at the Harvard T.H. Chan School of Public Health, where she studied the unique environmental health and safety concerns raised by engineered nanomaterials and nanotechnology applications. Key aspects of her research involve investigating the immunotoxicity and genotoxicity of engineered nanoparticles and the development of high throughput/high content assays.