“…In Mexico, a special geographical distribution has been found, see in the Figure 1, that crosses the states of San Luis Potosí, Zacatecas, Guanajuato, Querétaro, and Coahuila, seventeen states in the central, northwest and southwest of the Mexico present natural fluorine contamination in groundwater and its presence has been associated with rocks with quartz, feldspars, fluorite and apatite. [3][4][5] In Mexico, states such as Durango and Chihuahua where dental fluorosis is considered endemic, up to 9.23 mg/L of fluorides have been reported in tap water. 6 Vázquez-Bojórquez et al published in its review study in 2022 that the fluoride content in tap and bottled water in Mexico, particularly in northern and western region, represents a public health problem since levels are above 1.5 mg/L.…”