Skip Navigation
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Your Environment. Your Health.

Progress Reports: University of Washington: Wildlife Applications to Remediation Decision-Making

Superfund Research Program

Wildlife Applications to Remediation Decision-Making

Project Leader: Michael J. Hooper (Texas Tech University)
Grant Number: P42ES004696
Funding Period: 1995 - 2006

Learn More About the Grantee

Visit the grantee's eNewsletter page Visit the grantee's eNewsletter page Visit the grantee's Twitter page Visit the grantee's Facebook page Visit the grantee's Video page

Progress Reports

Year:   2005  2004  2003  2002  2001  2000  1999  1998  1997  1996  1995 

Studies during the last year have focused on finishing investigations of small mammal metal exposure and effects, performing analysis of oxidative stress endpoints and assessing metal uptake in hibernating toads.  Two large studies were performed to complete the project’s assessments of metal uptake from Anaconda Smelter Site soils in laboratory-reared deer mice.  The first was performed in adult mice (50-day-old) dosed with 3% soil in their diet and exposed for 48 days.  Soil metal concentrations encompassed low, medium and high levels as described in earlier updates.  Arsenic, lead and cadmium accumulated in a dose-dependent fashion in all tissues analyzed while copper and zinc levels did not vary, as anticipated for these well regulated essential metals.  Most importantly, blood lead levels that increased through the three doses were effective at inhibiting ALAD (delta-aminolevulinic acid dehydratase) activity in only the low and medium soils while the mice fed high metals soils had ALAD activities at control levels.  The lack of ALAD inhibition in the presence of blood lead levels that should have severely inhibited the enzyme is consistent with findings from field studies on these sites performed earlier in this study, indicating that the feeding model project researchers have developed has strong potential for implementation as a bioassay for superfund soils. The actual mechanism for this finding is likely reactivation of the ALAD activity by transient increases in blood Zn levels during feeding bouts.   A similar study is now being completed where deer mice were dosed from birth (lactationally from Anaconda soil-dosed dams for the first 21 post-natal days, 3% soil in the diet thereafter) through 100 days of age to evaluate the effects of life-long exposure in comparison to adult only exposure.  Project researchers have characterized and implemented glutathione, gamma-glutamyl cystein ligase and TBARS (thiobarbituric acid reactive substances) assays for application to study tissues to assess their utility as oxidative stress biomarkers that might function better than ALAD for mixed-metal soils.  Finally, a preliminary study that evaluated metal uptake in Bufo cognatus, the Great Plains toad, led to development of hibernation protocols for a more complete hibernation experiment that encompasses the typical eight month hibernation period for the focal toad species.  This definitive study is under way and encompasses 12 different treatments that will examine uptake and a suite of sub-lethal endpoints, such as metabolism, water balance, morphometrics, and ALAD inhibition.  These treatments represent a range of doses including: cadmium at three levels (30-400 ug/g soil), lead at three levels (10-1000 ug/g), elevated lead combined with copper at two levels, elevated lead combined with zinc at two levels, and elevated lead combined with both copper and zinc at the higher levels.

Back
to Top