Aluminium in drinking water from subsurface wells along the northern coast of Santa Catarina, Brazil and the potential risks to public health

ABSTRACT

The water withdrawal from household subsurface wells for human consumption purposes is a common practice adopted by the population of Santa Catarina (Brazil) to offset demand peaks necessary to satisfy their water needs, when main supply sources, such as surface waters, become inadequate due to contamination, access difficulties, or rationing periods. However, these underground waters are not always assessed to determine their quality and whether they are fit for the purposes and free from health risks. Three sampling campaigns were conducted over a year at household wells in São Francisco do Sul region, totalling 21 samples to evaluate the aluminium content and hydrogen ion potential (pH). The data were statistically organized into comparative graphs to identify patterns and support interpretations. The results indicated Al values above the established limits (0.20 mg/L) in eight samples throughout the year, with significant increases observed in the summer. An acidic pH was also diagnosed, which enhances the Al bioavailability. The detection of aluminium levels above legal limits increases the risk of chronic exposure and development of neurodegenerative diseases. Public policies should be implemented to guide the appropriate use of groundwater and water treatments to reduce Al concentrations to acceptable drinking water levels.