Proximal Sensing of Soil Pollution by Heavy Metals Using a Portable X-ray Fluorescence Analyzer in Subarctic Industrial Barren: Limitations and Perspectives

Along with severe climatic conditions of an industrial barren in the Arctic region comes the possible exposure to pollution not typically seen in natural habitats. This study aimed at developing and testing an express methodology based on a field-portable X-ray fluorescence analyzer (pXRF) to assess soil pollution on an industrial barren site in the impact zone of the copper-nickel enterprise in the Murmansk region, Russia. We combined a field survey of the surface soil layer at multiple locations (n = 86) with two validation approaches based on the standard ICP-MS measurements and a lab experiment on the artificial spiking with the estimated concentrations of heavy metals. Different soil types dominating the area (i.e., Podzol, Histosol, and Histosol/Podzol) as well as different homogenization and preparation methods (i.e., grinding, air drying, and grinding samples to a particle size of <2 mm and <0.08 mm) were compared. Although pXRF overestimated Cu and Ni contents, a significant positive correlation (p < 0.05) was shown between pXRF observation and the “true” values based on the standard approaches and lab experiments. Based on the analyzed linear relationships, calibration coefficients were estimated for each soil type and implemented to increase the accuracy of the pollution assessment at the subarctic industrial barren. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022.