Estimating Source Apportionment of Heavy Metals Contamination in Surface Soil based on Positive Matrix Factorization (PMF) model around Cerrito Blanco in San Luis Potosi, Mexico

In recent decades, heavy metal contamination in soils has received a significant concern on a global scale. Quantitative apportionment of heavy metal sources in the surface soil throughout extensive regions is a perplexing task. This study indicated a receptor model to evaluate the heavy metal concentrations of various sources for the soil and the related contamination impacts. In this study, the surface soil at the Cerrito Blanco in San Luis Potosi, Mexico was chosen as the case study location to reveal the potential pollution sources of heavy metals. The research suggested the combined use of the positive matrix factorization (PMF) model for quantitative assessment of contamination sources and spatial distribution techniques for the conception of pollution sources, which forms the foundation for later soil contamination control and treatment. Throughout the study region, a total of thirty-nine samples of surface soil were collected. However, the mean concentration levels in the soils of Co, Cr, Cu, Ni, and Pb were lower than the permissible standards for soils. But it may be concluded that heavy metals have been contaminated in the surface soil since the mean concentration levels of As and Cd was higher than their permissible standard values by around 5.43 and 1.19 times, respectively. The PMF findings demonstrate that four major diverse sources of heavy metals in this study area's soils were natural, past mining activities, groundwater, and human activities. The concentrations of heavy metals in surface soils were considerably influenced by natural activities, which were generally the main factors. The spatial distribution of soil contamination for heavy metals was also mapped using the Geographic Information System (GIS) technique. As a result, more focus will be required to assess the heavy metal contamination of soils in regions that have had increasing economic growth and prosperity, such as Mexico.