Sublethal and lethal effects on Rhinella Arenarum (Anura, Bufonidae) tadpoles exerted by the pirimicarb-containing technical formulation insecticide Aficida®

VERA CANDIOTI J.; NATALE G.S.; SOLONESKI S.; RONCO A.E.; LARRAMENDY M.L.

CHEMOSPHERE

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2010 vol. 78 p. 249 - 275

0045-6535

Acute toxicity, genotoxicity and cytotoxicity of the carbamate insecticide pirimicarb-containing commercial formulation Aficida® (50% pirimicarb) were evaluated on Rhinella arenarum (Anura, Bufonidae) tadpoles exposed under laboratory conditions. Lethal and sublethal effects were employed as bioassays for acute toxicity whereas micronuclei (MNi) induction and alterations in the ratio erythrocytes:erythroblasts were employed as end-points for genotoxicity and cytotoxicity, respectively. Cr(VI) (23 mg/L) and cyclophosphamide (40 mg/L) were employed as positive controls for toxicity and geno-cytotoxicity assays, respectively. In 25 Gosner stage (STD), the results revealed mean values of 402.0 and 223.6 mg Aficida®/L for LC-5024h and LC-5096h, respectively. When 37-39STD was exposed, the LC-5024h and LC5096h reached values of 239.4 and 181.7 mg Aficida®/L, respectively. Sublethal effects determined a mean EC-5096h of 133.85 and 81.0 mg Aficida®/L in those 25STD- and 37-39STD-treated tadpoles, respectively. The results demonstrated that in 48 h-exposed tadpoles, a MNi increase was only found in those 80.0 mg/L Aficida®-treated individuals. When tadpoles were exposed to Aficida® during 96 h, only those 160 mg/L-treated individuals showed a significant increase in MNi frequency. Concentrations ranging from 80.0 to 250.0 mg Aficida®/L resulted in cellular cytotoxicity, revealed by a decreased proportion of circulating erythrocytes and an enhancement of erythroblasts. Accordingly, this species could provide a suitable and useful experimental model for biomonitoring aquatic ecosystems.