Toxic and genotoxic effects of the imazethapyr-based herbicide formulation Pivot H on montevideo tree frog Hypsiboas pulchellus tadpoles (Anura,Hylidae)

PÉREZ IGLESIAS, J M; SOLONESKI, S; NIKOLOFF, N; NATALE, G S; LARRAMENDY, M

ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2015

0147-6513

Acutelethalandsublethaltoxicityoftheimidazolinoneimazethapyr(IMZT)-basedcommercialfor-mulation herbicidePivotHs (10.59%IMZT)wasevaluatedon Hypsiboas pulchellus tadpoles. Whereas mortality wasusedastheendpointforlethality,frequencyofmicronuclei(MNs)andothernuclearabnormalities aswellasDNAsingle-strandbreaksevaluatedbythesinglecellgelelectrophoresisassaywereemployedtotestgenotoxicity.Behavioral,growth,developmental,andmorphologicalabnormal-ities werealsoemployedassublethalendpoints.MortalitystudiesrevealedequivalentLC50 (96 h)valuesof 1.49mg/L(confidence limit,1.09?1.63)and1.55mg/L(confidence limit,1.51?1.60)IMZTforGosnerstage (GS)25andGS36,respectively.Behavioralchanges,i.e.,irregularswimmingandimmobility,aswellas adecreasedfrequencyofkeratodontswereobserved.TheherbicideincreasedthefrequencyofMNsincirculating erythrocytesoftadpolesexposedfor48htothehighestconcentrationassayed(1.17mg/L).However,regardlessoftheconcentrationoftheherbicideassayed,anenhancedfrequencyofMNswasobserved intadpolesexposedfor96h.Theherbicidewasabletoinduceothernuclearabnormalities,i.e.,blebbed andnotchednuclei,onlywhentadpoleswereexposedfor96h.Inaddition,weobservedthatexposuretoIMZTwithinthe0.39?1.17mg/Lrangeincreasedthegeneticdamageindexintreatmentslasting forboth48and96h.Thisstudyrepresentsthe first evidenceofacutelethalandsublethaleffectsexertedbyIMZTonamphibians.Finally,our findings highlightthepropertiesofthisherbicidethatjeopardize nontargetlivingspeciesexposedtoIMZT.