Study of groundwater quality regarding potentially toxic elements (Pb, Cd and As) in the aquifer of the Hermosillo Coast, Sonora, México

Climate change and potentially toxic elements (PTEs) contamination are global problems, so groundwater monitoring is of vital importance to meet the needs of the population, agricultural activities, the environment, and other productive sectors. The objective of the research is to study the quality of 99 groundwater samples from the aquifer of the coast of Hermosillo, Sonora. The physicochemical characterization was performed by potentiometric and gravimetric methods for pH, electrical conductivity (E.C), total solids (TS), total suspended solids (TSS), and total dissolved solids (TDS), and the concentration of PTEs was quantified by atomic absorption spectroscopy with the graphite furnace accessory and hydride generator when necessary. Water classification was performed using mathematical methods such as heavy metal contamination index (HMI), metal index (MI), and degree of contamination (CD). 37.37%, 78.78%, and 98.98% of the water samples were classified with low contamination levels, pure water, and low contamination; however, the samples most affected by high concentrations of As, TS, and TDS are RY4 and RY3. Constant monitoring and analysis of different ions is recommended for a better understanding of the water status to favor the society and economy of the state.