EVALUATION OF PHOTOTOXICITY OF AUTOMOTIVE OIL USED WITH Vicia faba AND Phaseolus coccineus

There is a huge generation of residual hydrocarbons resulting from the use of fossil fuels, which adversely affect organisms and ecosystems. The automotive wasted lubricating oil represents one of the most recalcitrant pollutants because its long persistence and slow degradation. That is why it is very important to carry out studies to assess the toxicity of this residue. In this work the response of two plant species, Vicia faba and Phaseolus coccineus, was evaluated during its growth in contamined soil with automotive wasted oil. The monitoring of temperature, pH and humidity of substrate was done along the growth process in both species. A higher percentage of germination was observed in seedlings of P. coccineus (78 %). The variables that determine toxicity in plants (height, stem thickness, root length, root volume and concentration of chlorophyll) show significant differences between soil contamined with wasted oil and the control soil (p <= 0.05). The correlation analysis showed that the most related variables were height-root length (R-2 = 0.74) and root length-root volume (R-2 = 0.85). The species that has greater tolerance to the hydrocarbon concentrations was P. coccineus. It was also possible to note that the prior treatment of composting in both soils is not sufficient to inhibit the toxicity of the wasted oil to grow V. faba and P. coccineus.