Polymer professor co-authors review paper on effects of nanomaterials on the Earth system

Dr. Nita Sahai, a professor of polymer science, is a co-author for an article just published in Science magazine. The review paper, “Natural, incidental, and engineered nanomaterials and their impacts on the Earth system,” provides a review of the fate of nanomaterials (natural and manufactured chemical substances that are rather small, about 1 to 100 billionths of a meter) and their effects on the environment and human health. Appearing in the publication’s March 29 issue, the article can be read online.

By addressing both naturally formed nanoparticles as well as man-made nanoparticles (whether unintentionally made (‘incidental’) or engineered for specific purposes (‘engineered’ nanoparticles), the paper encompasses a wider range of human-impact issues than reviews on any one type of nanoparticle. A very common example of natural nanoparticles in the environment are iron hydroxide minerals which are responsible for imparting the red, orange and yellow colors to soils. Titania nanoparticles are an example of engineered nanomaterials and are widely used in sunscreens and cosmetics.

Nanoparticles are everywhere

“This paper emphasizes that nanomaterials have played a role in the evolution of the environment and, indeed, of life on Earth through the entire history of the Earth on both local and global levels,” said Sahai.

Nanoparticles are prevalent in the natural environment. They can be inhaled into the lungs and, if not cleared, may cause respiratory and related health conditions. However, not all nanoparticles have a harmful effect on the environment or human health. Many engineered nanoparticles are useful for technological and biomedical purposes. Some types of natural nanoparticles, such as iron oxides, are critical to iron fertilization and the productivity of the oceans. 

The huge volume of incidental and smaller volume of engineered nanoparticles being created annually by humans is now challenging the earth’s environment and human health. This is why studying the fate of these nanomaterials in the environment and with the human body, and developing new theories and new techniques to study them is important.

Unique behaviors

What is unique about nanomaterials, Sahai adds, is that they have chemical, physical, or electrical properties distinct from their larger-sized counterparts. This gives them unique behaviors that cannot be easily explained by standard theories developed for larger-sized particles. Also, experimentally measuring the behavior and reactions of these very small particles is technically challenging. Therefore, new theories and new experimental methods need to be developed to understand the behavior of these nanoparticles and their interactions with the environment as well as with the human body. Some of these interactions are beneficial to the environment, human health, and the economy while others are deleterious.

Sahai, a professor in the College of Polymer Science and Polymer Engineering, is a trained geochemist whose research background is interdisciplinary between geochemistry and biochemistry. Her research areas relate to understanding the role of minerals (including nanoparticles) in the origins and early evolution of life on Earth, and on the interactions of minerals with the human body such as in the formation of bones and teeth. Recently, Sahai was recruited to join a new NASA Research consortium tasked with investigating life’s beginnings on Earth. She was recruited for the Center for the Origin of Life (COOL) research team, funded by NASA, due to her expertise with geochemistry and minerals.

Media contact: Alex Knisely, 330-972-6477 or aknisely@uakron.edu.