Nitrate content in groundwater in the metropolitan region of Fortaleza, Ceará: an alert

Abstract

Because of the general shortage of water in semiarid regions, as is the case of the State of Ceará, Brazil, the exploitation of groundwater is an important measure to supply water to the population. However, anthropogenic actions can impair the quality of this water. Considering that nitrate concentration is used globally as an indicator of water contamination and that levels greater than 10 mg/L N-NO3 cause harm to health, this study analyzed the nitrate levels in groundwater samples in the metropolitan region of Fortaleza. A total of 37 samples, obtained in the cities of Aquiraz, Caucaia, Pacatuba, Horizonte, Eusébio and Fortaleza were analyzed by visible light spectrophotometer. The samples were analyzed by laboratory technicians of the Ceará State Environmental Agency (SEMACE). The results revealed that 37.8% of the samples contained higher nitrate concentrations than specified by national standards as safe for drinking. These results corroborate other findings of high nitrate levels in groundwater from densely populated regions, as is the case of the Fortaleza metropolitan region, and that inadequate collection and treatment of sewage is one of the causes of this contamination.