Aluminum and Zinc levels in water from two towns having different water sources and treatment systems in São Paulo State

Abstract

Ground water treatment requires fluoridation and chlorination processes. In water from superficial sources, the treatment is based on flocculation,filtering, fluoridation and chlorination. Aluminum sulfate is used as a flocculant agent in this kind of treatment, which may increase this metalconcentration in water. Aluminum (Al) has been related to Alzheimer Disease (AD). Zinc (Zn) is also a very important metal for human health, especiallyfor senior populations. The objective of this study is to compare the concentrations of Al and Zn in potable water processes, considering different sourcesof water collecting and treatment. Water samples of two cities in Sao Paulo State were analyzed: Ribeirao Preto, supplied with ground water, and Atibaia,supplied with superficial water. Fifty samples of potable water were collected from faucets in homes of senior people and retirement houses. The valuesfound for Al showed that 24% of samples from Ribeirao Preto exceeded the maximum allowed values by national regulations, whereas values found inAtibaia were within allowed values. Zinc levels were under the maximum established values, in both cities, but the statistical test pointed at a significantdifference between them (p<0,0001), showing increased concentrations in Ribeirao Preto. The detection of metals above normalized values represents arisk for the health of the population and is important as information in the Public Health context, considering the toxicity of metals for human health.Future studies to verify the quality of public water supplies are extremely necessary.