Arsenic contamination in wood mice (Apodemus sylvaticus) and bank voles (Clethrionomys glareolus) on abandoned mine sites in southwest Britain

Arsenic can be highly toxic to mammals but there is relatively little infor mation on its transfer to and uptake by free-living small mammals. The aim of this study was to determine whether intake and accumulation of arsenic b y wild rodents living in arsenic-contaminated habitats reflected environmen tal levels of contamination and varied between species, sexes and age class es. Arsenic concentrations were measured in soil, litter, wood mice (Apodem us sylvaticus) and bank voles (Clethrionomys glareolus) from six sites whic h varied in the extent to which they were contaminated. Arsenic residues on the most contaminated sites were three and two orders of magnitude above b ackground in soil and litter, respectively. Arsenic concentrations in the s tomach contents, liver, kidney and whole body of small mammals reflected in ter-site differences in environmental contamination. Wood mice and bank vol es sn the same sites had similar concentrations of arsenic in their stomach contents and accumulated comparable residues in the liver, kidney and whol e body. Female bank voles, but not wood mice, had significantly higher stom ach content and liver arsenic concentrations than males. Arsenic concentrat ion in the stomach contents and body tissues did not vary with age class. T he bioaccumulation factor (ratio of arsenic concentration in whole body to that in the diet) in wood mice was not significantly different to that in b ank voles and was 0.69 for the two species combined, indicating that arseni c was not bioconcentrated in these rodents. Overall, this study has demonst rated that adult and juvenile wood mice and bank voles are exposed to and a ccumulate similar amounts of arsenic on arsenic-contaminated mine sites and that the extent of accumulation depends upon the level of habitat contamin ation. (C) 2000 Elsevier Science Ltd. All rights reserved.