PW09 Exposure and Effect Endpoints
Exhibit Hall
8:00 AM - Wednesday, 12 November 2003
(PW162) Hematological endpoints and blood ALAD activity in deer mice and meadow voles inhabiting the Anaconda Smelter Superfund Site, Montana.
Reynolds, K1, McFarland, C1, Schwarz, M2, Cobb, G1, McMurry, S1, Hooper, M1, 1 The Institute of Environmental and Human Health / Texas Tech University, Lubbock, TX, USA2 U. S. Fish and Wildlife Service, Grand Island, NE, USA
ABSTRACT- Although small mammals are abundant on many heavy metal-contaminated waste sites in North America, their use has primarily been limited to studies of metal accumulation. Health effects data are less common in studies on mining or smelting sites, yet are pertinent in the development of baseline ecological health assessments for NPL sites. Venous blood samples from deer mice and meadow voles inhabiting remediated and naturally vegetated areas contaminated with a gradient of heavy metals and arsenic were collected from the Anaconda Smelter Superfund Site, Montana. In addition to Pb, Zn, As, Cd and Cu concentrations, WBC, RBC, HGB, MCV, MCH, MCHC, PCV, and ALAD activity were measured or calculated for each blood sample. Although mice were collected across grids with four significantly different soil lead concentrations (range: 53 − 1387 ppm), no significant differences were found for HGB, PCV, or ALAD activity across grids. Mean ALAD activity in deer mice collected from two reference grids was 22.8 nmoles ALA/min/ml RBC (± SE 2.98; n = 23), while mean ALAD activity of mice colleted from the two grids most highly contaminated with Pb was 19.9 nmoles ALA/min/ml RBC (± SE 2.82; n = 20). A large number of blood samples with lead concentrations below our analytical detection limit prevented regression analysis between ALAD and blood lead. Although the protective properties of Zn in Pb-exposed rodents are well documented in laboratory studies, we found no significant relationships between blood Pb and Zn concentrations and ALAD activity. Nonetheless, this is the first report of ALAD enzyme activity in wild deer mice and meadow voles, and provides good baseline data for future studies. Funded by NIH ES04696, USEPA, USFWS and The ARCS Foundation.
Key words: heavy metals and arsenic, small mammals, ALAD, hematology endpoints