Avaliação da ecotoxicidade no solo entorno de uma fonte natural de água pelo teste Allium cepa L. e sua correlação com a presença de resíduos de agrotóxicos

Abstract

The use of agrochemicals in Brazil grows significantly each year. Along with it, cases of human poisoning, food and contaminated environments increase. One of the problems of environmental contamination is that there is a qualitative and quantitative lack of knowledge about the level of contamination of the soil by chemical agents associated with human action. Studies in this sense allow to evaluate the impact of these contaminants on the balance of the environment as well as the health of the human being and, in addition, make possible the proposition of biotechnological alternatives that seek the resolution or the minimization of this problem. Under such motivation, the present study aimed to study three points (Points 1, 2 and 3) of a soil used in agricultural practices, located in the southwest of Paraná, which contributes to the water quality of a natural source close to it, physical-chemical parameters, organochlorine and organophosphorous substances contents, and cytotoxicity and mutagenicity indexes for the bioindicator Allium cepa L. The mitotic indexes of the soil samples were found to be higher than the mitotic index of the negative control, being statistically different of this only to Point 2, indicating the presence of substances with mitogenic capacity at this point of collection. These data can be justified by the greater presence of phosphorus and potassium in this point of collection of the ground, because these are fundamental for the cellular division, being crucial for the radicular growth. The mutagenic indexes also presented a statistical increase in relation to the negative control, indicating the presence of mutagenic substances in the samples of the three points of collection. Possibly these effects may be due to the presence of trifluralin, cyanazine, endrin aldehyde, endrin, mevinphos, etoprophos, methyl paraxone and disulfoton sulfone in the identification and quantification test of organophosphorus and organochlorine compounds, because some of these agrochemical compounds are used prohibited in the country. These data show the importance of soil quality monitoring studies, both for the quality of this environment and the beings that inhabit or depend on it and, mainly, for the proximity of sources of human water supply.