House sparrow biomarkers as lead pollution bioindicators. Evaluation of dose and exposition length on hematological and oxidative stress parameters

CID, FABRICIO D.; FERNÁNDEZ, NOELIA C.; PÉREZ-CHACA, MARÍA V.; PARDO, RAFAEL; CAVIEDES-VIDAL, ENRIQUE; CHEDIACK, JUAN G.

ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2018 vol. 154 p. 154 - 161

0147-6513

House sparrows (Passer domesticus) have been proposed as a key ecological indicator of urban pollution.Remarkably, we lack knowledge about the physiological effects of lead on this bird species. Therefore, this studywas aimed to evaluate the effect of Pb on several physiological parameters in house sparrows exposed to environmentalPb concentrations. In a first experiment, birds were exposed to Pb sub-lethal doses (from 1.3 to14.0 μg of Pb/g animal/day) during 5 days, which resulted in a dose response increase of blood Pb levels anddecrease of blood ALAD activity. However, at the higher doses tested (> 7 μg of Pb/g animal/day) the bloodALAD activity inhibition (~82%) remained constant. Hematocrit and hemoglobin were significantly reducedonly at the highest-doses, and the stress indicator, heterophils to lymphocyte (H/L) ratio, did not show apparentchanges.In a second experiment, house sparrows were exposed to Pb in drinking water (12.3 ppm) during either 15 or30 days. Pb concentration used in this study was enough to produce blood lead levels equivalents to those foundrecently in house sparrows inhabiting urban areas, reduced blood ALAD activity and inversion of the H/L ratio.Decreasing blood ALAD activities were correlated with increasing blood Pb levels. In addition, Pb exposureproduced modification in the levels of hepatic antioxidant enzymes, increased GST activity and decreased CATactivity, without lipid peroxidation.In conclusion, our results suggest that blood ALAD activity is a reliable and sensitive biomarker for environmentalPb exposure in house sparrows, additionally chronic exposure produce physiological stress (H/Linversion) and small changes in antioxidant enzyme activity. Finally, this specie could be considered a bioindicatorfor monitoring the urban Pb contamination.