Renal Cadmium Concentrations in Mice and Shrews Collected from Forest Lands Treated with Biosolids

Abstract

AbstractThis study examined the long‐term effects of biosolids (mixed domestic‐industrial anaerobically digested sewage sludge) application to forested lands on kidney Cd concentration in omnivorous mice (Peromyscus sp.) and insectivorous shrews (Sorex sp.). Animals from eight biosolids‐treated sites, located in two different areas in western Washington, were examined and compared with those captured on seven control sites. Varying amounts of biosolids had been applied either 4, 11, or 15 yr previously. Kidney Cd was significantly greater in Sorex than in Peromyscus on all treatment sites. Though Cd levels in Peromyscus from some treatment sites were significantly increased over corresponding controls, levels from the highest dose treatment sites were comparable to controls found at other sites, so it is doubtful that biosolids had a significant long‐term effect on the omnivores. Cadmium levels in Sorex from all treatment sites except those receiving the lowest dose of biosolids were significantly greater than controls. Kidney Cd concentrations in shrews trapped from the 11‐yr postapplication sites were approximately equivalent to those in shrews trapped 2 yr after application on those same sites. However, the elevated levels of Cd found in Sorex, while highly significant statistically, did not appear to be biologically significant.