Aaron Specht, assistant professor at Purdue University, explains how he is contributing to a cleaner, healthier world by applying XRF to dried blood spot samples.
Aaron Specht, assistant professor at Purdue University, explains how he is contributing to a cleaner, healthier world by applying XRF to dried blood spot samples.*
While some trace elements, such as iron and zinc, help to keep us fit and healthy, others can have a devastating impact on our current and future health and longevity. Dangerous levels of toxic elements, such as heavy metals, can be found all around us; for example, in paints, water pipes and the byproducts of various industrial processes.
Identifying the sources of these elements and understanding their impact on the human body and our environment is the mission of Aaron Specht, an assistant professor in the School of Health Sciences at Purdue University in Indiana, USA. In recent years, Specht has used X-ray fluorescence (XRF) spectrometers, including Malvern Panalytical’s Epsilon 4 system, to measure the heavy metals in our bodies in innovative and minimally invasive ways.
Researchers pay millions of dollars to collect biological tissues. Using this process, we can get readings from those samples without destroying them, which means they can be reused for future studies. That’s incredibly powerful!
Aaron Specht — Assistant Professor, Purdue University
80Samples tested per day | 15,000Individuals tested | 4Epsilon 4 systems |
Adverse effects from exposure to elements including cadmium, lead, arsenic and mercury can range from fatigue and reduced IQ levels to organ damage, cancers and even death.1
The World Health Organization has estimated that lead poisoning alone contributes to 1 million deaths worldwide every year. Unsurprisingly, citizens of developing countries, which often have the most lenient industrial regulations, are among those hit hardest by environmental exposure to toxic elements.2
According to Specht, many people don’t realize just how widespread the issue of elemental exposure really is.
“It impacts us all, whether we know it or not. For example, recent studies have shown that around half of all U.S. adults were exposed to dangerous levels of lead as a child,” he explained.
“Children in particular are more susceptible to the impacts of lead, especially neurologically. And when you're exposed to any amount of it, it's doing bad things to your body.”4
Understanding the extent of this problem is crucial, as many sources of these heavy metals remain in common use in countries worldwide. And, as Specht revealed, we are still discovering new sources of exposure.
“A recent Wall Street Journal article claimed that miles of telecommunications lines are potentially leaching lead into waterways and nearby soils. Apparently, levels 14 times the U.S. Environmental Protection Agency’s approved standards for areas where children play have been recorded — if that’s the case, it’s astronomical!”5
Specht is currently leading a study that aims to shine new light on the relationship between Alzheimer’s disease and related dementias (AD/ADRD) and four toxic elements in particular: lead, mercury, arsenic and cadmium.
For this project, he and his team are using dried capillary blood spots collected from 15,000 individuals in the U.S. as part of a nationwide health and retirement cohort study sponsored by the National Institute on Aging. According to Specht, while technologies traditionally used to perform elemental analysis on blood samples, such as ICP-MS, are “effective, they also have their drawbacks.” For example:
But, for Specht, the greatest disadvantage is that ICP-MS analysis compromises the integrity of the sample, often destroying it completely.
To address these challenges, Specht has turned to Malvern Panalytical’s Epsilon 4 energy dispersive X-ray fluorescence (EDXRF) systems. These benchtop instruments analyze powder, liquid and solid samples without damaging them in any way. While a broad range of industries already use these X-ray fluorescence (XRF) spectrometers, their use in Specht’s field has been limited to date. However, Specht, who has a long history of adopting technological developments from other fields to support his work, is hoping to change that.
“XRF is definitely a technology that is currently under-utilized in environmental health — it has great potential.”
Working in collaboration with the Malvern Panalytical team, Specht has calibrated the Epsilon 4 systems to analyze samples, such as nail tissue and dried blood spots collected on filter paper — a process he believes is opening up a world of new possibilities when it comes to testing biological tissues.
He points to his latest study as a prime example. While the blood spots he and his team are testing were collected to map changes in the cohort’s DNA, the donors gave their consent for the samples to be used more broadly.
“I’m pretty sure the key reason we have been granted access to them is because we have developed a way to test them that doesn’t damage their integrity,” Specht said.
For Specht, maintaining the integrity of the sample isn’t the only reward those working in his field stand to reap.
Another big benefit of energy dispersive XRF is that it only requires a spot of blood captured on filter paper for testing.
“This makes the process of collecting samples easy, relatively pain-free, and it doesn’t require trained phlebotomists. You also avoid the dangers of contamination that can arise during the storage, transport and preparation of traditional blood samples,” Specht explained.
An additional plus is that the purchase price and running costs of each Epsilon 4 are relatively low.
“That means I can add requests for new units to existing grant applications — I don’t have to seek separate funding,” he added.
Other benefits include:
I think that’s where energy dispersive XRF really shines — it can help us have a bigger impact on communities by giving them the ability to monitor how these toxic chemicals are affecting them.
In the case of the retirement cohort study, the Epsilon 4 instruments will also help Specht trace additional metals present in the samples.
“Our study is primarily focused on testing for lead, mercury, cadmium and arsenic, because they are the four metals with the largest scope of literature supporting them,” he explained.
“But the good thing about energy dispersive XRF is that we can measure other metals present in the samples at detectable levels, including zinc, iron and copper, for example. We don’t have such a big knowledge base about these metals simply because they haven’t been looked at in the same detail — this is a unique opportunity to change that.”
With this equipment, we can collect a large volume of data that we can study in the future to determine what else is potentially impacting the neurological health outcomes and other health outcomes of this cohort.
One of the most exciting aspects of the integrity-preserving process Specht has developed is the new doors it opens.
“Now that we have a way to test a blood spot without destroying it, we can request access to existing collections — if suitable patient permissions are in place,” he explained. “And it’s surprising how many places collect and store blood spots; for example, hospitals collect them from every newborn. Understanding whether these babies are impacted by these toxic metals and to what levels could help us demonstrate why programs to address these issues are so important!”
For Specht, helping to drive more awareness of the dangers of exposure to toxic elements is a major motivation in his work.
“We used to have all these federal and state programs to monitor the levels of these metals, but, in our hubris, we decided they were no longer necessary. For example, here in Indiana, they did away with mandated universal tests for children,” he revealed. “But now Indiana and other states are bringing them back because they’ve discovered that our children are still being poisoned, there are still significant problems and we're still identifying new sources.”
He described federal government plans to replace all the old lead water service lines in the U.S., as “long overdue,” especially given that there are still an estimated 1.7 million of those pipes in place nationwide.
“If we want an indication of how dangerous this problem can be, we only need to look at what happened in Flint, Michigan,” Specht added. “Tackling heavy metals is a problem that people have traditionally put to one side when making big public health changes.
“But I hope we don’t make that mistake as we move forward, and that’s why monitoring these metals and reporting on their impact is important. With XRF, we can easily identify sources of exposure and the communities being affected so action can be taken. And our hope is that by reducing the sources, we’ll eventually reach a point where our children aren’t exposed to these dangers anymore.”
A lot of the research I’m involved in is trying to make the world a healthier place to live in.
In April 2014, the City of Flint changed their municipal water supply source from the Detroit-supplied Lake Huron water to the Flint River. The switch caused water distribution pipes to corrode and leach lead and other contaminants into municipal drinking water.
Flint residents flagged a serious change in their water quality almost immediately. But their water supply wasn’t switched back to Lake Huron until 2015, and by then, the damage had been done. Investigations into liability and health impacts are ongoing.7
* A testimonial from Aaron Specht, assistant professor, Purdue University. Views represented are not affiliated with Purdue University.