Abstract No:
1666
Abstract Type:
Student Poster
Authors:
J Malone1, E Wells2
Institutions:
1Purdue University, Prophetstown, IL, 2Purdue University, West Lafayette, IN
Presenter:
Jacob Malone
Purdue University
Faculty Advisor:
Ellen Wells
Purdue University
Description:
Particle-Induced X-Ray Emission (PIXE) spectroscopy and X-Ray Fluorescence (XRF) are non-destructive methods to quantify elemental concentrations in a sample. A total of 382 road dust samples from northern Lake County (NLC), Indiana, USA were analyzed for lead (Pb) with PIXE at the University of Notre Dame, before being sent to Purdue University for XRF analysis. We completed a comparison of results obtained by these two analytical methods. This research will help us to understand how different non-destructive analytical methods work in dust and soils analyses.
Situation/Problem:
NLC is home to many industries including a steel plant and an oil refinery. Legacy contaminated sites including many superfund sites and brownfields exist in the region and could contribute to heavy metal exposures. Community members have raised concerns regarding industrial impacts on environmental pollution and health. Non-destructive methods for environmental sample analysis have been promoted for community-based work due to their low cost, but less is known about differences in performance between different nondestructive analytical methods. Particle-induced X-ray Emission (PIXE) spectroscopy and XRF were utilized to analyze the samples in a variation on a "round-robin" study, with goals of understanding the differences in quantification in PIXE versus XRF methods. This poster will assess how the different analytical methods quantified elemental concentrations of Pb and describe the strengths and weaknesses in each of these methods.
Methods:
A total of 387 road dust samples across the region were collected by scientists and community members between 2023-2024. Samples were analyzed with PIXE at the University of Notre Dame and XRF at Purdue University using standard methods. Five samples were excluded from statistical analysis due to high differences in reported concentration (>300ppm), leaving 382 samples for analysis. Summary statistics of concentrations, percentiles, and the difference by method were calculated. Wilcoxon signed-rank test, paired t-test, and Spearman's correlation coefficients were used to compare reported concentrations.
Results / Conclusions:
The median and interquartile range for Pb was 58 ppm (30, 109) for PIXE and 39.76 (22.35, 70.42) for XRF. The average difference (PIXE-XRF) was 28.11ppm (standard deviation: 49.28); PIXE and XRF values were significantly different when analyzed via student's t-test (p<0.01). There was strong correlation between measurements from the two methods (Spearman's rho: 0.78, p-value<0.01). Although Pb concentrations were significantly different, there were no statistically significant differences between sample ranking by percentile (Wilcoxon signed-rank test p=0.25). While there are, on average, slightly higher concentrations reported by PIXE, the two methods rank the values similarly. Further statistical analysis exploring differences at very high or low concentrations and comparability of concentrations for additional metals in both analyses will be conducted to better explore this comparison. The results are likely to be useful for understanding potential differences between these two assessment methods in future environmental studies.
Core Competencies:
Community Exposure
Secondary Core Competencies:
Chemical Sampling and Instrumental Analysis
Work Environments, Occupations, and Industrial Processes
Choose at least one (1), and up to five, (5) keywords from the following list. These selections will optimize your presentation's search results for attendees.
Asbestos, lead, and dust
Environmental protection and monitoring
Labs – Health & Safety, Testing
Based on the information that will be presented during your proposed session, please indicate the targeted audience practice level: (select one)
Practitioner: Practitioner is a job title given to persons in various occupational fields who are trained to assist professionals but are not themselves licensed or certified at a professional level by a certification body recognized by the National Accreditation Recognition (NAR) Committee of IOHA. The IH/OH practitioner performs tasks requiring significant knowledge and skill in the IH/OH field, such as conducting worker exposure monitoring and, in some cases, may even function independently of a professional IH/OH but may not be involved in the breadth of IH/OH practice nor have the level of responsibility of a professional IH/OH certified by examination.
The IH/OH practitioner requires a certain level of education that can be obtained from an accredited university or equivalent. Additional training in specific skill sets that provide additional career paths to the IH/OH practitioner can also be obtained. IH/OH practitioners may also serve as team leaders or project managers.
Was this session organized by an AIHA Technical Committee, Special Interest Group, Working Group, Advisory Group or other AIHA project Team?
No
Are worker exposure data and/or results of worker exposure data analysis presented?
No
How will this help advance the science of IH/OH?
Compares two common non-destructive analytical soil/dust analysis methods (PIXE vs XRF), which can guide environmental health researchers to choose the best method for them. Highly relevant to environmental exposures in superfund sites, as well as those near large industrial facilities with heavy metal concerns.
Have you presented this information before?
No
I have read and agree to these guidelines.
Yes