The overconsumption of pesticides in the agricultural productive chain contributes significantly
to environmental degradation, in its various matrices. In aquatic ecosystems, abundantly found
in the Amazon region, this problem becomes more complex, because the high toxicity of some
pesticides and their inappropriate use represent a great and potential risk of contamination of
water bodies, an environment which, is, in most cases, the main final destination of pesticides
applied in the crops. In this context, the main objective of this research is to estimate the
potential risk of contamination by pesticides in surface waters in the Mojuí River sub-basin, in
the Santarém micro-region in Baixo Amazonas, State of Pará. Studies of this nature help to
identify possible areas susceptible to contamination by pesticides and, as these studies are
scarce in this region, they are necessary and urgent for the implementation of policies aimed at
protecting aquatic resources. The development of the work was carried out based on publicly
available data about: toxicology (LC50) and physicochemical properties (half-life, water
solubility, organic matter, sorption coefficient, among others) of the twenty-two (22) most used
pesticides in the study area; and of data that characterize the landscape diversity of the Mojuí
River sub-basin, such as altimetry data, land use and occupation, soil types, etc. As an important
analytical tool, Geographic Information Systems (GIS) were used for the analysis and treatment
of spatial data, as well as for the integration of different types of data, with the aid of Qgis 2.18
software. As a result of this work, a thematic risk map was obtained identifying the main areas
subject to pesticide contamination in the study region. This map contains information that may
be useful to direct future studies addressing the issue of pesticide contamination, as well as
assisting in decision-making by water resource managers in this and other regions, given that
such a methodology is robust and can be replicated to different regions respecting the
environmental peculiarities of each location.
|
