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This work assessed the groundwater hydrogeochemistry and the drinking water quality of 10 wells supplying the urban area of Zamora, Michoacán, Mexico. Two sampling campaigns were conducted in May 2018 (dry season) and November 2018 (wet season) to describe the chemistry of the water and its interaction with the rock. Physical and chemical constituents (temperature, pH, electrical conductivity, color, turbidity, solids, total hardness, total alkalinity, chemical and biochemical oxygen demands), major components (Ca2+, Mg2+, Na+, K+, SO42−, PO43−, HCO3−, CO32−, Cl−, N-NO3−, and N-NH3), as well as trace elements (As, Fe, Mn, Ba, Al, Sb, Co, V, Cu, Cd, Cr, Ni, Zn, Tl, Pb) were analyzed. Results showed groundwater with a slight tendency to alkalinity. The hydrogeochemical facies observed are Ca2+-HCO3− in all sites. Hydrochemical diagrams indicate immature, cold, non-saline, and uncontaminated water with short residence time. Water–rock interaction predominates. The water in the study area is appropriate for drinking use according to Mexican and international regulations with an excellent quality in 7 wells and good in the other 3.

This research presents and discusses information concerning the spatial distribution of heavy metals (Pb, Cu, Zn, Ba, Co, Cr, Ni and V) in the urban environments of Mexico City using geographical information system and statistical analysis. Superficial soil samples (n = 146) were analyzed. The highest contamination indices were found in the north and center zone of the metropolitan area. In contrast, the surrounding rural fields show a lower impact grade. The higher concentrations of Pb, Cu, Zn and Ba were observed as being related to high vehicular traffic, nevertheless other elements such as Co, Cr, Ni and V do not show anthropogenic influence and their content can be attributed to the parental rock. The results are compared with previous surveys carried out in 2003 in order to evaluate temporal deposition trends. No changes were found on reported concentrations except for Cu and Zn, whose concentration has increased in later years. The results suggest that spatial distribution analysis and results in comparison with previous studies could be useful for the management and sustainable development of the metropolitan area of Mexico City.

Concentrations of vanadium, chromium, cobalt, nickel, copper, zinc, antimony, and lead were measured in Ficus benjamina leaves from the Mexico City urban area in order to assess their enrichment against background values. The instrumental analysis was performed using inductively coupled plasma mass spectrometry and the analytical method was tested using two certified reference materials from the National Institute of Standards and Technology (1547 Peach Leaves and 1573a Tomato Leaves). Enrichment factors were calculated, i.e., total to background concentration ratio, for each metal. Low enrichments of vanadium, cobalt, nickel, and copper (≈2), and mild enrichments of chromium and zinc (4.4, 4.5 respectively) were found in the entire area; oppositely, high enrichments were assessed for antimony (28.6) and lead (17.2). However, results indicate that metal concentrations strongly depend on the specific urban sub-area. Increments of metals were attributed to natural, vehicular, and industrial sources.

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