Assessment of heavy metals in soils adjacent to an open-air landfill in Manabí, Ecuador

Abstract

Open-air dumps constitute significant sources of soil contamination by heavy metals. This study evaluated the concentrations of lead (Pb), cadmium (Cd), and mercury (Hg) in soils adjacent to the open dump located in the Cristo del Consuelo community, Olmedo canton, Manabí, Ecuador. Two sampling points (control and impacted sites) were established in accordance with the NTE INEN ISO 10381-1 standard, using composite soil samples collected at a depth of 0–15 cm. Lead and cadmium concentrations were determined by X-ray fluorescence, while mercury was analyzed using ICP-OES. The results showed Pb concentrations ranging from 10.56 to 24.96 mg/kg and Cd from 0.16 to 1.01 mg/kg, with increases of 130% and 140%, respectively, in the dump area compared to the control site. Mercury was not detected. Although the measured values remained below the limits established by TULSMA (2003), the enrichment of Pb and Cd indicates moderate anthropogenic influence, highlighting the need for continuous monitoring and preventive environmental management measures.