FLUORINE AND ARSENIC IN URBAN AQUIFERS OF EL BAJIO MEXICO: AN UNATTENDED PROBLEM

Anthropogenic activities can contaminate surface water and groundwater, although groundwater quality can be affected also by geogenic processes related to the geological environment and physico-chemical phenomena. In El Bajio there are not surface water bodies available for urban supply. Groundwater is the only one water supply source. Groundwater from Juventino Rosas aquifer system has high concentrations of As and F in some cases exceeding the Mexican standards for drinking water, NOM-127. Groundwater temperature can reach 50⁰C. In neighboring cities have been also detected high concentrations of As in groundwater water, mainly in Salamanca City, where As is from natural and anthropogenic origin. There are manifestations of health problems that could be linked to the intake of poor quality water. Subsidence faults and fractures facilitate a fast migration of surface contaminants. In the whole region the consumption of the so-called purified water diminished health affectations, although people prepare food with pipeline water. There are not remediation programs because people consider dental fluorosis an aesthetic problem and arsenisism can evolve to health problems of difficult diagnosis after long periods of time of exposure. Local and regional Water authorities have not alternative programs for water supply. The well density is one of the greatest in the Country. Rainfall is scarce and aquifer recharge very low. Most of wells are used for irrigation. There are not social programs to inform population above water quality problems. Water is becoming a political flag that can change drastically the political image of whom inform of water problems. Treatment plants could be a solution but administration and maintenance become in additional responsibilities for local governments and local and regional water authorities. The interaction of water authorities, population leaders and the Academy can propose solutions with social participation. Studies with viable solutions must be carried out considering financial situation and technical support.