Posted May 12, 2023
Featuring Jack Harkema
Harkema Jack 352
Dr. Jack Harkema

University Distinguished Professor and Albert C. and Lois E. Dehn Endowed Chair in Veterinary Medicine Dr. Jack Harkema has been recognized by the Society of Toxicology as one of seven individuals with significant contributions to the foundational development and advancement of US nanotoxicology research.

Specifically, Harkema was honored by the Nanoscience and Advanced Materials Specialty Section, formerly known as the Nanotoxicology Specialty Section, for his contributions toward understanding the pathobiological processes induced by nanomaterials in various organ systems.

“I am honored to receive this recognition from my SOT colleagues and collaborators,” says Harkema.

Nanotoxicology is the study of adverse effects caused by occupational exposure to engineered nanomaterials and environmental exposure to ultra-fine particulate matter. (PM0.1 is particulate matter with aerodynamic diameter up to 0.1 micrometers, or one tenth of one millionth of a meter). These materials are roughly the size of a virus, or even smaller (Figure 1). Nanoparticles can be found in the air from sources of pollution, such as diesel engine exhaust, but they also can be engineered for use in many products, such as cancer therapeutics, toiletries, and food.

Figure 1

“Nanoparticles are found everywhere in our environment and even in our food,” says Harkema. “For example, some chewing gum is coated with a white, glossy material containing titanium dioxide nanoparticles. Like all chemical substances, it is important to ensure the safety of nanomaterials, which animals and people may be exposed to in our food, water, and air.”

Harkema focuses on nanoparticles found in air pollution and has found that these minute airborne materials have the potential to exacerbate respiratory illnesses like asthma.

“Nanoparticles can heighten inflammatory and immune responses. When we engineer them that way for therapies, like nanoparticles used in vaccines, that’s a good thing. They’re adjuvants that improve your body’s protective immunity. But it can go the other way, too. Let’s say a person with asthma is exposed to nanoparticles at work, and when they leave, they breathe in an outdoor allergen like pollen—their allergic reaction can be stronger than normal, resulting in an asthmatic attack,” says Harkema.

Harkema says that it is the job of the Environmental Protection Agency and Food and Drug Administration to consider science-based regulations for nanomaterials found in our environment and workplaces in order to ensure public health. Also honored by the Society were Dr. Gunter Oberdorster, Dr. Andre Nel, Dr. Philip Demokritou, Dr. Andrij Holian, Dr. Kent Pinkerton, and Dr. Jim Riviere.