Genotoxic biomonitoring in peripheral blood of Rattus norvegicus (Berkenhout, 1769) from contaminated sites in Argentina

Abstract

This study evaluates the genotoxic response in the peripheral blood of rats (Rattus norvegicus) from Argentina’s Matanza-Riachuelo basin, using micronucleus frequency in reticulocytes (MNiR) and the reticulocyte/erythrocyte ratio (R/E) as biomarkers. Over 3 years, blood samples from 170 rats were collected at sites with varying contamination levels, assessed through Industrial Water Quality Index (WQIi) and Sewage Water Quality Index (WQIs) derived from spatiotemporal data.Wistar rats served as control groups for reference values. Significant variations in WQIi, WQIs, and biomarkers were observed across sites and periods. Generalized linear mixed models (GLMM) revealed a negative correlation between R/E and WQIi, linking industrial contamination to impaired hematopoiesis. MNiR was negatively related to WQIi and positively influenced by intrinsic factors like male sex and weight, suggesting dietary and hormonal modulation of genotoxicity. These findings validate the micronucleus test in rat reticulocytes as a robust genotoxicity indicator, integrating extrinsic and intrinsic variables to assess human exposure risks in contaminated environments.