Fitotoxicidad del material particulado sedimentable (MPS) generado en la zona urbana del cantón Cuenca

Abstract

In this work the phytotoxicity of Sedimentable Particulate Material (acronym in spanish: MPS) generated in the urban area of canton Cuenca was determined by bioassay, determining if the MPS concentration is so abundant and if its composition contains toxic substances enough to affect the normal development of plants. Bioassays are conducted with the assumption that the organisms tested are keys to higher organisms in the natural environment (Escalante, E. 2000). The MPS was collected at three sites in the urban area of canton Cuenca, by the method described in the Unified Text of Secondary Environmental Legislation of the Ministry of Environment (acronym in spanish: TULASMA). It is known that particulate matter are present in a variety of toxic substances including heavy metals and anions (CEA. 2009), so that the determination of the concentration of MPS was done using gravimetric analysis, by atomic absorption spectroscopy for heavy metals, and by the adapted method with reference EPA 300.1 for anions. Subsequently phytotoxicity was evaluated in four species by bioassay of germination and root- and hypocotyl-elongation, with a method adapted by Sobrero M. (2005), Guide 850.4200 USEPA-OPPTS, in seeds of Lactuca sativa, Brassica oleraceaitalica, Allium cepa, Raphanussativus. In the bioassay seeds were exposed to different dilutions of the aqueous suspension of MPS, the results were dependent on the concentration and the tested specie, showing different levels of phytotoxicity.