Industry Driven: Heavy metals in NJ soils

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Fast and easy to use, SciAps XRF is 'a lifesaver' in the field

Recently, Dr. Ashaki Rouff, an associate professor, and Suah Yekeh, a second year Ph.D. student, in the Department of Earth & Environmental Sciences at Rutgers University, Newark investigated the soil in seven city parks for the presence of contaminants, including heavy metals, using SciAps X-200 XRF. What they learned will have them coming back this summer doubly equipped, using their newly purchased SciAps X-505 XRF and Z-903 LIBS analyzers.

The 2021 study, “XRF Evaluation of Heavy Metals in Parks of Newark, New Jersey,” revealed arsenic, cobalt, and lead in concentrations above New Jersey Department of Environmental Protection limits for high-contact recreational soils.

Newark is home to a wide range of industry and commercial activities linked to air pollution. Its aging infrastructure has led to previous investigations of the water systems and the discovery of lead within the water system. “We hear a lot about water pollution and particulates being injected into the atmosphere due to vehicular emissions. But we don't hear a lot about soil, which is actually a huge sink where these contaminants get deposited. That's one of the reasons why we are focusing on soil. It's important, and it's been overlooked,” Rouff says.

Most Newark recreational parks are near highways, in the middle of busy traffic areas, or by seaports, so the researchers targeted these areas where children play for hours to be evaluated for contaminants that have settled into the soils.

In-field improvements with SciAps

Rouff says SciAps XRF improved the efficiency and user experience of the project. “I’ve worked with other handheld XRF instruments in the past, but I much prefer the SciAps XRF. It was much easier to use. The software was much more user friendly and easier to navigate. Much better than [in my experience with] a competing XRF.”

They hadn’t received a lot of support or guidance with the previous analyzer, she says. “SciAps actually came in and did a demo for us, which was quite informative,” Rouff says. “When we borrowed the XRF through the Academic Loaner Program, we were trained how to use it and collected invaluable data. It solidified the decision to purchase analyzers from SciAps.”

“Using the XRF is going to be a lifesaver in terms of doing analysis in the field.”

Expanding the field work using X-505 and Z-903 LIBS

In summer 2022, they will return to the parks with their SciAps X-505 (which has superseded X-200) to re-sample some of the areas and take additional measurements to see if the elevated levels of arsenic, cobalt, and lead are a chronic problem, or if maybe there was some sort of perturbation that elevated those levels. “We want to make sure that we can replicate the measurements before we go on to the next steps,” says Rouff.

And with a SciAps Z-903 LIBS (laser) analyzer that can measure any element from H to U, they’ll also look for carbon.“We're excited to use the LIBS because I want to see what's going on with carbon in the soil, also. I want to understand how the metal contents and the carbon content correlate. We already know from our speciation analyses that we do have metals bound to a lot of organic material, and so I think it will be interesting and informative to also quantify carbon in the soils and see what the correlations look like,” says Rouff.

In the next phase of the study, they will conduct a complete analysis of the soils to get an assessment of the potential mobility of the contaminants. They’ll also study the potential of the contaminated soils to infiltrate the air, which could potentially affect ingestion pathways if the contaminants are bound to smaller particles.

“We borrowed the XRF, were trained how to use it, and collected invaluable data. It solidified the decision to purchase analyzers from SciAps.”

Mapping in the lab, and more

Yekeh, the study’s co-author, and the undergraduate student she is mentoring, Kathleen Martin, are currently mapping the 110 samples they collected in the parks to show the concentration and potency from one area to another. “I’m going to use the GIS heat map signature to see if these contaminants are around playgrounds only, or if they are around soccer fields as well. Using the GIS will allow me to track the contaminants in this year and compare them to the next year. And then I’ll compare the parks to each other to see if this is a continuous thing throughout the parks,” Yekeh says.

Sharing these findings with the public is one benefit of the analysis, but the easy-to-adopt instrumentation is leading to more. Rouff will deploy the newly purchased analyzers on smaller-scale undergraduate research projects that connect to the whole project. “We can engage a broader range of students in this type of public or community-based research. So I can run summer programs with undergraduates, and using the XRF is going to be a lifesaver in terms of doing analysis in the field,” Rouff says.

Rouff has already added XRF analysis to soil modules in environmental and geochemistry courses for those students who are not necessarily participating in research but will benefit from the immediate analysis of samples in the classroom. “We are going to be developing and modifying course modules to include the XRF wherever we can,” Rouff says.