Determination of lead (Pb) Pollution Levels in Soils from Different Mechanical Garages and Bus Stations in Dakar Using X-ray Fluorescence (XRF) Spectrometry

Heavy metals are among the most toxic pollutants found in soils. Lead, in particular, is one of these metals that exerts harmful effects on living organisms even at very low concentrations. Therefore, the objective of this study is to assess the level of lead contamination in soils from garage areas. In this work, we collected soil samples from eight different garages, including five bus stations and three mechanical workshops. On each site, we collected a composite sample that we analyzed in order to quantify the lead content using X-ray fluorescence spectrometry (XRF). The XRF device provided the elemental analysis results of each sample in parts per million (ppm). These results highlighted the presence of trace metal elements such as lead (Pb), copper (Cu), chromium (Cr), zinc (Zn), and arsenic (As), as well as other less toxic metals like iron (Fe), molybdenum (Mo), zirconium (Zr), sulfur (S), and tin (Sn). The comparative study of the concentrations found shows a heterogeneous distribution of lead in the soils of the garages, with values ranging from 36.62 to 53.26 ppm. Concentrations are higher in the soils of mechanical workshops than in those of bus stations, with a few exceptions. The most concerning site (S4) shows the maximum lead content of 53.26 ppm, which does not exceed the alert level of 400 ppm set by the US EPA for soils. Thus, the soils do not currently present major health risks for adults, but long-term exposure could negatively affect children living near these areas.