Determinação dos limites de toxicidade, em diferentes níveis tróficos, de tensoativos fluorados utilizados no combate a incêndios

Abstract

The foam generating liquids (LFG), containing fluorinated surfactants. They can affect the environment in different ways, from handling, storage, use in preventing and firefighting or involving incidents with flammable liquids. In this context, it is of paramount importance the study through an assessment of the toxicity of LFG. Thus, the aim of the present study was to determine the toxicity of LGE, in the concentrations used by the Fire Department of the State of Paraná (1,05 g L-1, 3,15 g L-1 and 6,30 g L-1), according to the type of fire to be fought, the behavior in bioindicators of different trophic levels. Was analyzed being these the mortality and immobility assays of a microcrustacean (Artemia salina L.); a lettuce (Lactuca sativa) seed germination assay; a escape of earthworms (Eisenia fetida) assay; and a cytotoxicity of MTT ((3-(4,5-dimetiltiazol-2-il)-2,5-difenil tetrazolium) with cell culture assay. For the bioindicator A. salina, one can observe a toxic effect of sample A1 (at a concentration of 100%), A2 (at concentrations above 25%) and A3 (almost all concentrations), with an evident dose-dependent effect within the group and between the evaluated groups In the test with plant bioindicator (lettuce) all samples (A1, A2 and A3) affected the number of germinated seeds, germination speed and percentage and root length, also with a dose-dependent effect. In the escape test with animal bioindicator earthworms samples A2 and A3 were considered toxic because the escape percentage was 70% and 100%, respectively, again with a more evident toxic effect at the highest concentration of LGE (A3 = 6% of LGE). Already in the in the test with monkey mullata kidney cells none of the samples were toxic.. As follows, it is necessary to develop safe and conscientious methods of use by the segment professionals, considering that this foam generating liquid was toxic to almost all bioindicators and biomarkers used at present, and because they are is dumped into the environment, without any control or dimensioning of the quantity.