Avaliação ecotoxicológica do extrato solubilizado de telhas de fibrocimento utilizadas na construção civil

Abstract

The use of asbestos cement roofing roof tiles and their subsequent disposal can cause various social and environmental problems, such as air pollution, population health, soil and water contamination. In Brazil there are specific legislation for the management of construction waste, aimed at mitigating the impacts arising from disposal. The main objective of the present work was to evaluate the ecotoxicity, in Daphnia magna, caused by the possible solubilization of chemical compounds present in asbestos cement tiles. For this, four tiles containing mineral fiber and synthetic fiber from three different manufacturers were purchased from construction shops, two of which were composed of synthetic fiber (sample 1 and sample 2), one containing mineral fiber (sample 3) and one containing mineral fiber and pigmentation (sample 4). The solubilized extracts were obtained after reducing the size of the tiles with hammer / hands, drying and grinding to granulometry of 9.5mm, according to NBR 10.006 (2004). The acute ecotoxicity assays with Daphnia magna were performed according to the norm of NBR 12.713 (2016) and the results expressed in Toxicity Factor (FT), the lower the FT, the higher the toxicity. Four trials were performed for each sample, and the 01 test was performed with the fresh extract and the others were performed with the extract after 10, 15 and 30 days of obtaining. When comparing samples 02 (synthetic fiber) and 04 (mineral fiber and pigmentation), FT 57% and 97% respectively, both from the same manufacturer, greater toxicity was observed in sample 02. When compared only samples containing mineral fiber (samples 03 and 04, with FT 63% and 97%, respectively) only sample 03 presented ecotoxicity. When comparing the ecotoxicity of samples 01 and 02, both with synthetic fiber (FT 100% and 57% respectively), it was verified that only sample 02 showed ecotoxicity. Thus, two solubilized extracts were toxic to the aquatic organism D. magna, a sample containing synthetic fiber (sample 02, FT 57%) and a sample containing mineral fiber (sample 03, FT 63%) and two solubilized extracts were not (sample 01, FT 100%) and one containing mineral fiber and pigmentation (sample 04, FT 97%). No difference was observed in the FT values observed in the ecotoxicological tests between the fresh and refrigerated samples. These data require complementary ecotoxicological analyzes, as well as the need for studies by manufacturers to search for less toxic raw materials and production alternatives and to raise public awareness of the toxic effects caused by the inappropriate use and disposal of asbestos cement tiles.