Purdue Institute for a Sustainable Future (ISF) | July 15, 2024

Using toenails to measure exposure to toxic metals


In this post, Aaron Specht, an assistant professor in the College of Health and Human Sciences and a member of the Purdue Institute for a Sustainable Future, discusses his research “Benchtop x-ray fluorescence to quantify elemental content in nails non-destructively,” which was recently published in Science of the Total Environment with the support of the Centers for Disease Control and Prevention National Institute of Occupational Safety and Health and the National Institutes of Health National Institute of Environmental Health Sciences.


What did you want to know?

We specifically set out to determine whether we could use x-ray fluorescence technology to monitor heavy metal exposures using toenails. Previous methods utilize expensive, time consuming, and burdensome analytical methods to investigate heavy metals in biologic tissues. Our proposed method uses a non-destructive approach for measurement that significantly reduces sample preparation and takes measurements in minutes.

What did you achieve?

The results from our new method were the same or better than those using the current gold standard methods. We were able to replicate the findings from inductively-coupled plasma mass spectrometry (ICP-MS) without digestion of the sample or any preparation besides washing the toenails. Basically, we were able to drop the samples in a cup, irradiate them for 7.5 minutes using our x-ray fluorescence setup, and identify a signal using a previously validated normalization technique to achieve detection limits on-par or lower than current ICP-MS limits.

What is the impact of this research?

This work broadens our ability to track where people are exposed to toxic heavy metals. Heavy metal exposure remains a global public health problem and with this equipment we can open up the possibility of implementing surveillance of heavy metal exposures into public health programs around the world.