Purdue Researcher Develops Lead Detection Breakthrough Tech

Lead is a naturally occurring metal found in the Earth’s crust, but it can be a serious health hazard, particularly to young children and women of child-bearing age. Any exposure to lead is considered harmful.

Lead exposure testing can be difficult and challenging due to the lack of symptoms and limitations of current test methods.

However, a Purdue University researcher in the College of Health and Human Sciences has developed noninvasive methods that detect levels of lead exposure in bone and blood faster, easier, and with greater sensitivity at the point of care than traditional methods.

Patent-pending technology created by Aaron Specht, assistant professor in the School of Health Sciences, allows portable X-ray fluorescence (XRF) analyzers to measure lead exposure in bone and blood. Specht said bone measurements are important to detect chronic exposure.

“Lead mimics calcium when it enters the body, hijacking pathways to the brain and causing havoc,” he noted. “But like calcium, it accumulates in bone itself. By analyzing bone, we get a measure of 90% of the lead that was ingested. Because bone turns over so slowly, we can measure a very long accumulation time: up to 30 years’ worth of exposure with this new method.”

Specht has also created a method to detect lead levels in drops of dried blood. He said the traditional method for blood assessments requires taking a venous draw then sending it to a lab for analysis.

“Our new method detects lead using dried blood spots, which are much easier to collect; they require just a finger prick and only a very small volume of capillary blood,” he said. “As long as there’s more than 10 microliters of blood on that dried blood spot, we will have an accurate measurement of lead.”

Specht claims his innovation could benefit health officials worldwide, including those who serve hard-to-reach populations and rural communities.

“It can be difficult to assess their lead exposure levels because it’s hard to get them to a centralized clinic, unlike in an urban environment where people visit a clinic often,” he stated. “By using a portable XRF analyzer, health officials can travel to a community, conduct testing, quickly receive results and move on to the next community.”

Specht’s research into the separate methods was published in the September 2024 issue of Current Environmental Health Reports and the March 2021 issue of Environmental Science & Technology, both peer-reviewed publications. Specht disclosed the innovations to the Purdue Innovates Office of Technology Commercialization, which has applied for patents to protect the intellectual property.

Testing Bone for Lead Exposure Levels

Exposure to lead can lead to brain and central nervous system damage, development and growth delays, learning and behavior problems, hearing and speech problems, reproductive health problems, kidney injury, high blood pressure, anemia, and more.

Specht said the industry standard to measure lead exposure is a blood test. “That test only measures the past 30 days,” he explained. “If the test is administered outside that 30-day window, especially in children, you’re unlikely to get a result that is reflective of the chronic cumulative activity in the body.”

Older technology used to measure bone lead exposure levels has various drawbacks including size, expert knowledge, rare elements, and speed.

“It weighs about 150 pounds because it requires liquid nitrogen-cooled detectors,” he said. “It is incredibly difficult to use; we had trained physicists who would operate the system. It uses a cadmium source, which was produced in Russia, but we can’t buy anymore. And it takes 30 minutes to complete one measurement.”

Using Specht’s method with portable XRFs addresses those drawbacks for bone tests.

“I train people to use this system in 30 minutes. It’s a very simple ‘point-and-shoot’ process, and the XRF analyzer’s tablet reads out the results within a few minutes,” Specht commented. “Once trained, that person will be able to do measurements to identify community-level lead exposures.”

The next step in developing the innovation is convincing health leaders to use it in national cohort studies and routine surveillance.

“We can then determine what national standards for cumulative lead exposure looks like,” Specht declared. “The main argument for continuing to use blood tests is that we have used them in the past, but the advantages for bone in identifying real health consequences should outweigh our stubbornness.”

Improving Blood Tests for Lead Exposure Levels

As with the bone test technology, Specht’s innovation to test dried blood spots improves the accessibility for hard-to-reach communities and rural populations. But it also has a better sensitivity than currently available tests.

“The current blood lead measurement technology has a detection limit that is higher than the level that we know causes harm,” he said. “That technology may measure as low as 3.5 micrograms per deciliter, but there will be no result for someone slightly below that. Our detection limit is 1 microgram per deciliter, which most experts agree is the level of detection to identify if someone is truly harmed.”

The National Institutes of Health, U.S. Department of Defense, and the JPB Foundation have provided funding to support Specht’s research.

The Purdue Innovates Office of Technology Commercialization operates one of the most comprehensive technology transfer programs among leading U.S. research universities. Services provided by this office support the economic development initiatives of Purdue University and benefit the university’s academic activities through commercializing, licensing, and protecting Purdue intellectual property. In fiscal year 2024, the office reported 145 deals finalized with 224 technologies signed, 466 invention disclosures received, and 290 U.S. and international patents received. The office is managed by the Purdue Research Foundation, a private, nonprofit foundation created to advance Purdue University’s mission.

Purdue University is a public research institution ranked among top 10 U.S. public universities and with two colleges in the top four. More than 105,000 students study at Purdue across modalities and locations, including nearly 50,000 in person on the West Lafayette, Ind., campus.