Cianotoxinas: impacto na qualidade e disponibilidade de água

Abstract

The Brazilian distribution of water resources, despite the significant national reserve of drinking water, occurs in a discrepant way and the decrease in water quality further reduces its supply in certain regions. In this sense, the accelerated increase in the nutritional supply in reservoirs, because of pollution from industrial, domestic and agropastoral activities, triggers the eutrophication process that culminates in the proliferation of cyanobacteria. These microorganisms have as their main characteristic of importance for unique health, the ability to produce secondary metabolites, called cyanotoxins, implicated in cases of poisoning in humans and domestic and wild animals. Given the above, the objective of this work was to analyze the impact of the presence of cyanotoxins in natural and artificial water reservoirs intended for human and animal supply. A bibliographic survey was carried out in the main national and international databases of scientific documents with subsequent elaboration of syntheses, analysis and writing of the review. From the data collected, it is possible to verify that the cyanobacteria have a wide geographic distribution, but they present ideal conditions for development and maintenance in lentic freshwater systems, enriched with nitrogen and phosphorus from anthropogenic activities, which favors the events of flowering of toxic species. Research carried out in Brazil shows that, although the Northeast region has characteristics that favor the proliferation of these microorganisms, such as varied periods of drought, poor access to basic sanitation and low water quantity in reservoirs, there are high levels of blooms of toxic cyanobacteria in reservoirs of the entire national territory. The edition and publication of specific legislation for the control and prevention of cyanotoxin intoxication in the country was driven by the only cases of deaths in humans due to microcystin intoxication in the world, which confirms the importance of the toxic blooms of these microorganisms in the unique health. In view of this, it is possible to conclude the importance of cyanotoxins as possible causes of morbidity and mortality in humans and animals in Brazil, requiring constant monitoring of their presence in water bodies in order to better structure control and prevention measures.