Avaliação de atividade estrogênica e toxicidade de lixiviados de resíduos sólidos urbanos.

Abstract

The leachates from municipal solid waste, dark liquid formed by the decomposition of the waste mass over the percolation of rainwater, from sanitary landfills or not, can be a major source of contamination of groundwater and surface water, if there is no soil sealing and appropriate treatment. The complex mixture of organic and inorganic substances present in the leachate can cause toxicity to organisms exposed or generate any endocrine disruption in humans and other animals, even at very low concentrations. Due to the environmental problems currently occurring, such as soil contamination, or contamination of groundwater and surface when close to the waste disposal sites, and to evaluate the potential toxicity of the leachate, bioassays of acute toxicity experiments were conducted to measure the effects of toxic agents on organisms of different trophic levels (Lactuca sativa, Daphinia simillis, Danio rerio e Aliivibrio fischeri) and evaluate the effectiveness of treatment processes. In order to determine the presence of estrogenic activity and quantify estrogens present in the samples were performed a in vitro assay - YES (Yeast Estrogen Screen) and high-performance liquid chromatography (HPLC/FLU) for the determination of bisphenol A (BPA) and estrogens: estriol (E3) , 17β - estradiol (E2) and 17α - ethinylestradiol ( EE2). Raw leached samples from two landfills and a garbage dump located in the Baixada Fluminense were collected, and only one of the landfills collecting treated leachate was possible. All samples analyzed, raw and treated, proved to be toxic to the organisms analyzed in the study. The YES assay was effective in determining estrogenic activity in some samples, however, in some cases, the complexity of the matrix resulted in uncertainties in the results, since the interference from other chemical compounds present in the sample interfere in the results of estrogenic activity. Chemical analysis showed the presence of endocrine disruptors E2, EE2, E3 and BPA in samples of raw and treated leached.