Metal Concentrations in Tissues of Meadow Voles from Sewage Sludge‐Treated Fields

Abstract

Food‐chain uptake of Cd, Pb, Zn, and Cu by meadow voles (Microtus pennsylvanicus) was assessed in wheat (Triticum aestivum var. Ranger) and old‐field plant communities receiving sludge or fertilizer applications. Sixteen 0.1‐ha enclosures received either 8,963 kg ha−1 year−1 Milorganite (6‐2‐0, N‐P‐K) or 1,569 kg ha−1 year−1 ureaphosphate fertilizer (34‐11‐0), or were untreated (controls).Mean Cd concentrations in livers and kidneys of voles (all age/sex groups) from sludge‐treated fields in the second year of application were significantly higher (p < 0.05) than controls; in the first year only females from sludge‐treated wheat fields had higher levels than controls. Ranges of mean Cd concentrations in voles from sludge‐treated fields were 0.1–1.1 µg g−1 wet weight in liver samples and 0.4–6.6 µg g−1 in kidneys; ranges in controls were 0.01–0.04 µg g−1 in liver and 0.01–1.6 µg g−1 in kidneys. Cadmium concentrations in voles from fertilizer‐treated fields did not differ from controls.Liver and kidney Cu concentrations were elevated in some age/sex groups from sludge‐ and fertilizer‐treated fields. There were no treatment differences in Pb or Zn concentrations, nor in organ or whole‐body weights.Short‐term (2‐year) effects on mammals of sludge application to land appear to be benign, despite accumulation of metals in vital organs.

Municipal sludge metal contamination of old‐field ecosystems: Do liming and tilling affect remediation?

“…Over the 11 years of nutrient enrichment, heavy metal accumulation in the soil [12,33] and uptake by earthworms [12,33], plants [12,34], and meadow voles [10,12,32,34] were found to be significantly greater in sludge-treated plots than in fertilizer or control plots. In spite of subplot manipulations, heavy metal concentrations by treatment were similar to past findings in these plots as well as in other studies (e.g., Beyer et al [35] and Pietz et al [36] for soil and worms).…”

“…Beginning in 1978 and continuing through 1988, sludge was applied monthly (May-September) at a rate of 1,792 kg/ha for a total yearly application of 8,960 kg/ha. Fertilizer was applied on the same days as the sludge at a rate of 314 kg/ha, or 1,569 kg/ha per year to provide an equivalent N-P-K subsidy (see Levine et al [12] and Anderson et al [32] for additional information concerning experimental design). Heavy metal concentrations in the Milorganite and fertilizer have been previously documented [11,12,32,33].…”

“…Fertilizer was applied on the same days as the sludge at a rate of 314 kg/ha, or 1,569 kg/ha per year to provide an equivalent N-P-K subsidy (see Levine et al [12] and Anderson et al [32] for additional information concerning experimental design). Heavy metal concentrations in the Milorganite and fertilizer have been previously documented [11,12,32,33]. In sludgetreated plots, mean yearly loading rates ranged from 177 to 529 g/ha for Cd, 2,867 to 3,410 g/ha for Cu, 2,177 to 4,238 g/ha for Pb, and 7,758 to 11,478 g/ha for Zn; in fertilizer-treated plots, loading rates were 2 to 6 g/ha for Cd, 2 to 3 g/ha for Cu, 8 to 20 g/ha for Pb, and 26 to 52 g/ha for Zn (calculated from means presented in Levine et al and fertilizer (F) plots; the broken lines indicate the manipulated subplots.…”

Assessment of mercury concentrations in small mammals collected near Las Vegas, Nevada, USA

“…The majority of these studies have focused on Superfund sites (www.epa.gov/superfund), seasonal wetlands, landfills, mining operations, sludge disposal sites, or other sites that are all heavily contaminated. Several authors have documented the importance of small mammals as an intermediate step in the transfer of toxic contaminants to higher tropic levels, and hence important implications regarding the potential bioaccumulation of contaminants can be drawn from small mammal studies (Taylor et al, 1981;Anderson et al, 1982;Hunter et al, 1987;Brueske and Barrett, 1991;Brewer and Barrett, 1995;Kaplan et al, 1996;Laurinolli and Bendell-Young, 1996).…”

Effects of municipal sludge on locomotor activity and exploratory behavior of meadow voles, Microtus Pennsylvanicus

“…While there was no significant difference in Cd found in the kidneys of control and sludge-exposed voles, there was a strong trend towards higher levels of cadmium in the sludge-exposed individuals ( Table 2). The bioaccumulation of heavy metals by primary consumers has been demonstrated numerous times [7,8,14,17].…”