Chromosomal aberrancy in white-footed mice (Peromyscus leucopus) collected on abandoned coal strip mines, Oklahoma, USA

This study was undertaken to determine the genetic consequences to small mammals of long‐term exposure to heavy metal pollution. A secondary goal was to continue the process of validation of chromosomal aberration analysis as an in situ biological monitoring tool. During the spring, summer, and fall of 1992, white‐footed mice (Peromyscus leucopus) were collected from four metal‐polluted, abandoned coal strip mines and three uncontaminated reference sites in eastern Oklahoma, USA. Chromosomal aberrations were scored from standard bone marrow metaphase chromosome spreads. Seasonal differences were detected for aberrant cells (cells containing one or more chromosomal lesions) per individual (p = 0.0004), but there were no differences among sites or between sexes. Males and females were tested separately for lesions per individual, and neither sex showed a significant difference among sites but both showed seasonal differences across sites. Finally, a chi‐square analysis showed that the difference between total lesions and aberrant cells was not significantly different among sites (p = 0.635), indicating that lesions were distributed among cells in approximately the same way among all sites.