Stark Street Materials, a Portland State University Business Accelerator company-in-residence, is working to end medicine’s reliance on lead for radiation shielding. Stark Street uses the element bismuth to create the next generation of non-toxic radiation shielding materials.
The majority of radiation shielding garments in the United States use lead to protect the wearer from X-rays and other radiographic imaging techniques. Lead aprons are commonly used in healthcare settings ranging from dentistry to gastroenterology to cardiology. Research has shown these garments have the potential to release lead dust into the environment, increasing the potential for harmful levels of exposure, which can lead to brain, nervous system and kidney damage.
Though the toxicity of lead is well documented, the medical field has relied on lead-based materials to block and shield patients and personnel for the past century because of its low costs.
Classified as an element in 1753 by French chemist Claude Francois Geoffroy, bismuth is considered one of the best substitutes for lead in radiation shielding technology as it greatly reduces radiation beam intensity. Bismuth is safe for human consumption and is one of the active ingredients in Pepto-Bismol. Until recently, high costs have created a barrier to using bismuth for radiation shielding, but that’s changing.
“Bismuth has gotten a lot cheaper recently,” said Anna Brown, Founder and CEO of Stark Street Materials, and a former graduate research assistant at PSU. “As part of my graduate program, we developed a way to surface stabilize bismuth and integrate it with polymers in the hope of turning it into new materials that we’re hoping to use to create very high density, very efficient, non-toxic radiation shielding garments.”
Using bismuth-based materials has the potential to revolutionize the way radiation-shielding materials are used in the healthcare industry. The bismuth materials will be more flexible and fabric-like, but also machine washable, which current lead garments are not.
“Our materials are non-toxic, which means we can redesign garments so that they can have direct contact with the patients and medical personnel who use them. Unlike lead garments, our materials can be sterilized using a washing machine without the concern of leaching harmful toxins.”
Brown credits PSU’s Business Accelerator as being integral to her success in transitioning from scientist to entrepreneur.
“Taking the leap from being a scientist to an entrepreneur is really scary and PSU has been unbelievably supportive. It’s really exciting to be part of a university that’s prepared to put their money where their mouth is and really encourage scientists to make that leap.”