Northern pocket gophers (Thomomys talpoides) as biomonitors of environmental metal contamination

Abstract

Abstract-We live-trapped 40 northern pocket gophers across two years from the Anaconda Smelter Superfund Site, Anaconda, Montana, USA, to determine their exposure to five metal contaminants and effects of exposure on selected measurements. Soil, gopher blood, liver, kidney, and carcass samples were analyzed for arsenic, cadmium, lead, copper, and zinc. Hematological parameters, kidney and liver porphyrins, and red blood cell ␦-aminolevulinic acid dehydratase (ALAD) activity were also measured. Micronutrients Cu and Zn were detected in all tissues analyzed, and Cd, Pb, and As were detected less frequently. We report differences in metal distribution among different tissues and differences in bioaccumulation for different metals within the same tissue. No significant differences were observed in concentrations of Zn or Cu in any tissue across the study site, but relationships between lead in soil and lead in carcass proved especially strong (r 2 ϭ 0.80; p Ͻ 0.001; n ϭ 18). Among biomarker data, we observed a negative relationship between concentration of lead in the soil and ALAD activity in gophers with detectable concentrations of lead in their blood (r 2 ϭ 0.45; p ϭ 0.006; n ϭ 15). Results of this study suggest that northern pocket gophers are useful biomonitors of environmental Pb, Cd, and As contamination, and their broad geographic range across North America could allow them to be an important component of site-specific metals assessments.

Screening of δ-aminolevulinic acid dehydratase from Pseudomonas strains as biosensor for lead and some other metals contamination

“…Bacterial ALAD activity as a sensor for biologically available Pb(II) that poses considerable hazard to the ecosystem and human health in contaminated environments (Pang 1995). The small size of bacteria, their ubiquitous distribution in the environment, and their metabolic versatility make heme prime targets for research in environmental biosensors (Reynolds et al 2006). Ogunseitan et al (2000) study extends previous investigations of the effect of Pb(II) on ALAD to include the sensitivity of this enzyme in bacterial populations and communities In our study, we observed that there was statistically significant relations between Pb(II) concentrations and ALAD activity from P. pseudoalcaligenes and P. putida.…”

Metal exposure and effects in voles and small birds near a mining haul road in Cape Krusenstern National Monument, Alaska

“…In gophers, a blood Pb concentration greater than about 1.0 μg/g dw was associated with suppressed ALAD enzyme activity (Reynolds et al 2006). A similar threshold for effects on ALAD activity in relation to blood Pb concentration was reported for deer mice (McBride 2007).…”

“…For example, rodents, including mice and gophers, captured near metal smelters that displayed histopathological effects from metal toxicosis had mean Pb concentrations of between 5 and 15 μg/g dw in the liver and >30 ug/g dw in the kidney (Stansley and Roscoe 1996;Damek-Poprawa and Sawicka-Kapusta 2003;Reynolds et al 2006). Mean liver Cd concentrations in affected rodents of those same studies ranged from about 4.0 to 9.0 μg/g dw.…”

Characterization of the structural and functional diversity of indigenous soil microbial communities in smelter‐impacted and nonimpacted soils

“…As a result, the site was listed on the U.S. Environmental Protection Agency's National Priorities List in the early 1980s, and reclamation of the site is ongoing to decrease off‐site movement of metal contaminated soils by wind dispersal and runoff [4]. Previous studies have been conducted at this site to monitor the negative effects of metal contamination on vegetation [3,5], birds (T.J. McBride, 2002, Master's thesis, Texas Tech University, Lubbock, TX, USA), and small mammal populations [6]. Few studies have characterized the effects of metal contamination on soil microbial communities at this site.…”