Discussion. The ecotoxicological effects of pesticides can be assessed by monitoring the status of communities in real ecosystems or through the use of laboratory toxicity tests. Litterbag field test showed no influence of the treatments on the organic matter breakdown, suggesting a scarce contribution of soil macrofauna. The bait-lamina test, however, seemed to be useful for detecting the effects of GLY and CPF treatments on the activity of the soil fauna. CPF failed to give significant differences with the controls in the reproduction test and the results were not conclusive in the avoidance test. Although the field population density of earthworms could be affected by multiple factors, the effects observed on the reproduction and avoidance tests caused by GLY could contribute to its decrease, with the subsequent loss of their beneficial functions. Biomarkers measuring effects on suborganism level could be useful to predict adverse effects on soil organisms and populations. Among them, NRRT, a lysosomal destabilization biomarker, resulted in demonstrating more sensitivity than the reproduction and avoidance tests. The Comet assay was responsive only to CPF. Since DNA damage can have severe consequences on populations, it could be regarded as an important indicator to be used in the assessment of soil health. Conclusions.Reproduction and avoidance tests were sensitive indicators of GLY exposure, with the former being more labor intensive. Bait-lamina test was sensitive to both CPF and GLY. NRRT and Comet assays revealed alterations at a subcellular level, and could be considered complementary to the biological activity tests. Because of their simplicity, some of these bioassays seemed to be appropriate pre-screening tests, prior to more extensive and invasive testing.Recommendations and Perspectives. This study showed deleterious effects of GLY and CPF formulations when applied at the nominal concentrations recommended for soya crops. Further validation is needed before these endpoints could be used as field monitoring tools in Argentine soya soils (ecotoxicological risk assessment -ERA tools).

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-The objective of this work was to evaluate the effects of chlorpyrifos on earthworms and on soil functional parameters. An integrated laboratory-fi eld study was performed in a wheat fi eld in Argentina, sprayed with chlorpyrifos at two recommended application rates (240 or 960 g ha -1 a.i.). Laboratory tests included neutral red retention time, comet assay (single cell gel electrophoresis), and avoidance behavior, each using the earthworm Eisenia andrei exposed in soil collected 1 or 14 days after pesticide application, and the bait-lamina test. Field tests assessed organic matter breakdown using the litterbag and bait-lamina assays. Earthworm populations in the fi eld were assessed using formalin application and hand-sorting. The neutral red retention time and comet assays were sensitive biomarkers to the effects of chlorpyrifos on the earthworm E. andrei; however, the earthworm avoidance test was not suffi ciently robust to assess these effects. Feeding activity of soil biota, assessed by the bait lamina test, was signifi cantly inhibited by chlorpyrifos after 97 days, but recovered by the 118 th day of the test. Litterbag test showed no signifi cant differences in comparison to controls. Earthworm abundance in the fi eld was too low to adequately test the sensitivity of this assessment endpoint.Index terms: Eisenia andrei, agricultural soil, fi eld assay, laboratory bioassay. Biomarcadores para a avaliação dos efeitos de clorpirifós em minhocas e em parâmetros funcionais do soloResumo -O objetivo deste trabalho foi avaliar os efeitos do clorpirifós sobre as minhocas e sobre parâmetros funcionais do solo. Foi executado um estudo integrado campo-laboratório, em uma plantação de trigo na Argentina, onde foi aplicado clorpirifós em duas doses recomendadas (240 ou 960 g ha -1 a.i.). Os ensaios laboratoriais incluíram tempo de retenção do vermelho-neutro, ensaio cometa (eletroforese em gel de célula única) e teste de fuga, cada um com a minhoca Eisenia andrei exposta aos solos coletados 1 e 14 dias após tratamentos, e teste com a lâmina-isca. Nos bioensaios de campo, avaliou-se a decomposição da matéria orgânica em sacolas com alfafa e com a lâmina-isca. As populações de minhocas foram avaliadas no campo com uso do método de extração com formalina e remoção manual. O tempo de retenção do vermelho-neutro e o ensaio cometa foram biomarcadores sensíveis aos efeitos do clorpirifós na minhoca E. andrei; porém, o comportamento de fuga não foi efi ciente para avaliar tais efeitos. A atividade alimentar da biota do solo, avaliada pelo teste de lâmina-isca, foi signifi cativamente inibida pelo clorpirifós após 97 dias, mas recuperou-se no 118 o dia do teste. O teste de sacolas com alfafa não mostrou diferenças signifi cativas em comparação aos controles. A abundância das minhocas em campo foi muito baixa, para testar adequadamente a sensibilidade desta variável.Termos para indexação: Eisenia andrei, solos agrícolas, testes de campo, bioensaios de laboratório.

Contamination by 2,4,6-trinitrotoluene (TNT) is a global environmental problem at sites of former explosive production, handling, or storage, and could have deleterious consequences for human and ecological health. We investigated its sublethal effects to Eisenia fetida, using two nonspecific biomarkers. In coelomocytes of earthworms exposed 24, 48, or 72 h, we evaluated DNA damage (comet assay) and neutral red retention time (NRRT), using the filter paper contact test. Both percentage of damage (D%) and calculated damage index showed significant DNA damage at almost all concentrations, at all time points assayed. Along exposure time, two different patterns were observed. At the lower TNT concentrations (0.25-0.5 μg/cm2) an increased DNA migration at 48 h, with a decrease close to initial levels after 72 h exposure, was observed. This decrease could be attributed to activation of the DNA repair system. At higher concentrations (1.0-2.0 μg/cm2), the high DNA damage observed remained constant during the 72 h exposure, suggesting that the rate of DNA repair was not enough to compensate such damage. Analysis of NRRT results showed a significant interaction between time and treatment. After 48 h, a significant decrease was observed at 4.0 μg/cm2. After 72 h, NRRT presented a concentration-dependent decrease, significantly different with respect to control at 0.5, 1.0, 2.0, and 4.0 μg/cm2. The two assayed methods, performed on the same sample, showed clear responses to sublethal TNT exposure in E. fetida, providing sensitive unspecific biomarkers of cell injury and DNA damage.