Água da represa Billings usada para o consumo humano apresenta contaminantes microbiológicos e induz prejuízos comportamentais e astrogliose em zebrafish

Resumo (EN)

The Billings reservoir is the largest water-storage facility in the São Paulo Metropolitan Region, with only a small part of the reservoir used for water supply. Recently, the São Paulo Metropolitan Region has experienced the greatest water collapse ever recorded. Thus, the intensification of use of the Billings reservoir should be considered. The objective of this study was to evaluate the quality of the water from different areas of the Billings reservoir related to human consumption (water supply and fishing): Rio Pequeno, Rio Grande, and Bororé rivers. We performed microbiological and physical studies on water samples. Zebrafish were exposed to such water samples and their behaviors were evaluated. Finally, we studied central glial fibrillary acidic protein (GFAP) expression, which is related to neuroinflammatory processes. Water samples from Rio Pequeno, Rio Grande, and Bororé presented microbiological contamination for Escherichia coli and heterotrophic bacteria. Water from the Rio Pequeno river induced both motor/exploratory impairments and anxiogenic-like behavior in zebrafish. Water from the Bororé river induced behaviors in zebrafish related to respiratory impairments (hypoxia) as well as higher alarm reaction. Zebrafish exposed to water from the Bororé also presented astrogliosis, which seems to have happened in detrimental of the high heterotrophic bacterial contamination. Considering the present results of microbiological contaminants and behavior impairments as well as astrogliosis in zebrafish, the water from Rio Pequeno, Rio Grande, and Bororé rivers should be considered unacceptable for human use in their untreated state. Basic Sanitation Company should consider adopting rigorous processes of microbiological water treatment. Authorization for fishing at Bororé river should be reconsidered.