The search
for fuels to replace petroleum consumption has caused an increase in the
production of biofuels worldwide. The ethanol, which comes from sugarcane, is
an energy resource with low polluting potential, but its production generates
other environmental problems. On average, 10 to 15 liters of vinasse are
generated while preparing each liter of ethanol. Vinasse is the final
by-product of the biomass distillation, mainly for the production of ethanol,
from different cultures such as sugarcane. Because excessive quantities of
vinasse are produced, alternatives have been required for use, for example as
fertilizer, in a process known as fertigation. These excessive amounts of
vinasse applied in soils have generated adverse effects on soil properties and
to the organisms. This study carried out the toxic, cytotoxic and genotoxic
potential of sugarcane vinasse obtained from two different harvests (Samples I
and II), using the Allium cepa organism test. A.
cepa seeds were exposed to raw vinasse (RV) and diluted in different
concentrations: control soil + raw vinasse (SV); vinasse diluted in water at
50% + control soil (V 50%); vinasse diluted in water at 25% + control soil (V
25%); vinasse diluted in water at 12.5% + control soil (V 12.5%). The chemical
characterization of vinasse samples showed a low pH and high concentration of
potassium. The results demonstrate that the two RV samples tested are toxic,
since no seeds germination was observed. The cytotoxic potential was observed
in the sample II of SV and V (50%). All groups evaluated in samples I and II,
induced chromosomal alterations, statistically significant compared with
negative control. An increase in frequency of micronuclei in meristematic cells
was observed in the SV (Sample I) and all groups evaluated in samples II. Based
on the results it is concluded that the genetic material of the test-system was
damaged when exposed to sugarcane vinasse, suggesting that one should be very
careful in the use of this waste that has been used sometimes indiscriminately
in soils.