Taxco de Alarcón is an important mining site in Mexico. The town is a well-known tourist destination where the potable water quality is important for guaranteeing the health of the users. Due to the altitude of the city, the surface and rain water are the main sources of water. Thus, the aims of this study were to characterize i) the composition and chemical speciation of particulate matter suspended in water to determine the content of potentially toxic elements, and ii) the chemical and bacteriological composition of the potable water of Taxco de Alarcón, Guerrero, Mexico, according to the Mexican official norm NOM-127-SSA1-1994. The analyzed representative samples were taken from the municipal water distribution network, the water treatment plant, the Chacuhalco spring and a mixture of the waters of the Chontalcuatlán river, the Tenería spring, and the San Marcos and El Sombrerito dams. According to the results, 94 % of the analyzed samples did not comply with the standard NOM-127-SSA1-1994. Moreover, the distribution of the analyzed elements in the different chemical fractions of the particulate matter showed that the highest concentration of Cd (4.17 mg∙kg-1) is associated with the carbonate fraction. This means Cd is moderately bioavailable. On the other hand, the highest concentrations of Pb, Zn, Mn and Cu (62.2, 42.3, 243 and 1026 mg∙kg-1, respectively) were detected in the Fe-Mn oxyhydroxide fraction, also considered as moderately bioavailable, whereas the highest concentrations of As, Fe and V (24.0, 7583 and 31.3 mg∙kg-1, respectively) were associated with the residual fraction, considered as non-bioavailable. The results indicate that, to improve the quality of potable water, modifications must be incorporated along the water treatment processes, and in the distribution network and management.

A genotoxic study was conducted with 101 elementary school children (56 girls and 45 boys) in the 6–7, 8–9, and 10–12 age ranges from El Fraile rural community, which is located beside the El Fraile mine tailings in Taxco of Alarcon City, in northern Guerrero State, Mexico. For this, we used the alkaline comet assay in exfoliated buccal mucosa cells, scoring three genotoxic parameters: tail intensity, tail moment, and tail length. Additionally, we detected oxidative DNA damage through urinary 8-OHdG levels by enzyme-linked immunosorbent assay. We also evaluated a control group consisting of 101 children in the same age ranges from Chilpancingo City, Guerrero, who had never lived near mining zones. Genotoxic results showed that there was a significant increase in three genotoxic parameters and urinary 8-OHdG levels in the exposed children group compared with the control group. Analysis of MANOVA revealed that boys aged 8 and 9 years had higher DNA damage than girls from the same exposure group, and Spearman’s analysis identified a positive correlation between DNA damage and sex and age. This study provides the first valuable genotoxic data in children living in areas with environmental pollution.

The mining industry generates high concentrations of heavy metals (HMs) susceptible to being released into surface and ground water. The objective of this work was to determine the concentration and dispersion of HMs in surface water and ground water in a hydrological sub-basin located in southwest Mexico. The samples were collected as following: 24 samples from streams, rivers, and one lake, and 15 samples from springs, located along the Taxco-Cocula sub-basin. A total of 78 samples were collected in the dry and rainy seasons. Physicochemical parameters, major ions, and HMs were analyzed. The pH, Eh, electrical conductivity, and total dissolved solids were analyzed in situ, while the concentrations of anions, cations, and HMs were measured in the laboratory. The results were treated with multivariate analysis and PHREEQC simulation. The highest recorded values (in mg/L) were in surface water, where the HMs in the dry season were Al (28.63), As (0.60), Cd (1.78), Cu (1.10), Fe (68.27), Mn (21.47), Pb (0.02), and Zn (208.80). These high concentrations exceed the limits established by national and international regulations for drinking water. The ground water did not indicate pollutants associated to the mining industry. On the other hand, in the rainy season, the surface water showed a decrease in the concentrations of the measured heavy metals. The hypsometric gradient and the hydrogeological and meteorological characteristics of the Taxco-Cocula sub-basin are the factors that contribute to the dilution and dispersion of the HMs along the 60 km of its length.

En la última década se ha despertado un especial interés por la posible contaminación con metales pesados (MP) de la bahía de Acapulco, un destino turístico internacional. Los MP son un grupo de elementos químicos, tóxicos para plantas, animales, microorganismos y, por supuesto, los humanos. El consumo o una exposición constante a éstos se traduce en afectaciones directas a la salud pública. El abanico de enfermedades que pueden ocasionar es extenso y depende del MP que estemos hablando. Algunos males asociados con ellos son dermatitis, gingivitis, saturnismo, convulsiones, cefaleas, gota, osteoporosis, depresión, infertilidad, problemas en el embarazo, abortos, mutaciones genéticas, cáncer y muchas otras alteraciones fisiológicas.

Mining in Mexico has been present since pre-Hispanic times, playing a fundamental role in the country's socioeconomic development. The mineral deposits of the Taxco Mining District (northern Guerrero State) are divided into four mineralized zones: Huahuaxtla, Coxcatlán-Tlamacazapa, Buenavista de Cuéllar, and Taxco de Alarcón. This study focuses on the Huahuaxtla region, where mercury, a highly toxic element with irreversible effects on human and environmental health, was exhaustively extracted until the 1960s. The objective of this work was to investigate the chemical and mineralogical characteristics of rocks from historical mining works and mine wastes (MW) in Huahuaxtla to assess the potential for Hg release into the environment. Characterization techniques included X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS), and total mercury (THg) quantification. The composition of MW was dominated by calcium oxide, linked to the primary mineralization. Mineralogical and geochemical analyses revealed a low concentration of metallic sulfides, a high abundance of carbonates, and low THg levels. The mineralogical composition suggests these wastes pose a low short-term environmental risk. This is primarily due to their strong neutralizing capacity, which prevents the generation of acid mine drainage (AMD) and consequently limits the solubility, mobility, and bioavailability of mercury in the surrounding environment.