Integral aproach of Glyphosate-induced alterations in a South American caiman species.

POLETTA, GL., A. LARRIERA, P. SIROSKI, E. KLEINSORGE, MD. MUDRY.

Herbicides: Properties, Crop Protection and Environmental Hazards

Nova Science Publishers

Lugar: New York; Año: 2011; p. 189 - 210

Although current herbicide use attains greatly improved yields in agriculture, their non-target impacts have caused considerable concern worldwide. Herbicide application techniques aim to maximize the amount received by vegetation, but an important percentage of the agrochemicals applied disperse in the environment. Natural habitats can be exposed directly through overspray or drift and indirectly through runoff. Agriculture expansion in conjunction with the implementation of trangenic crops, has entailed an increase in the use of herbicide formulated products as well as pesticides mixtures. In Argentina, a constant increase in transgenic soybean single-cropping (Glyphosate resistant) has occured in the last years, based mainly in economic interests. This led to a corresponding rise in glyphosate-based formulations use, including more than 170 millions liters released to the environment in the last agricultural season. The exposure of an organism to these compounds may induce a cascade of events at the individual and population levels, which are not always easy to detect and correlate with the causal agent. The detection and quantification of several events in this cascade can be used as biomarkers of exposure and undesirable effects, serving as early-warning signals of populations environmentally exposed. However, the great majority of pesticide impacts are determined from experiments conducted under laboratory conditions and including only the active ingredient of the formulated product. Results obtained from these studies do not represent current field conditions, nor effects on organisms embedded in their natural ecological contexts. In the present chapter, we present an integral approach on the effects of Glyphosate and its most widely known commercial formulation, Roundup®, on a South American caiman (Caiman latirostris). We conducted a wide evaluation at different instances including laboratory controlled condition experiments, field-like experiments and a direct evaluation of environmentally exposed populations. Analysis was done in various C. latirostris life stages including embryos, hatchlings and adults, considering different ways of exposure, and through several endpoints of different biological meaning, such as genetic damage, developmental, enzymatic and metabolic parameters. Taken all data into consideration, this approach could be highly valuable at population and community levels of this wildlife species, allowing an integral insight in the interpretation of environmental contamination processess associated to the herbicide evaluated.