Impacts of Heavy Metal Contamination on Soil Microbial Communities. (3710)
Authors:
J. Kelly* - Loyola Univ. Chicago
Abstract:
The anthropogenic release of heavy metals to the environment can have significant, deleterious impacts on soil ecosystems. Because microorganisms are critical to soil ecosystem function, the impacts of heavy metal contamination on soil microbes is a significant issue. We examined soils in the vicinity of a zinc smelter in eastern Pennsylvania. The operation of this smelter has resulted in destruction of over 485 hectares of forest. We observed significant increases in both total and soluble soil metal loadings with increasing proximity to the smelter, including a 24-fold increase in total zinc. Microbial population size and activity were negatively
affected by the elevated metal levels, and metal contamination also resulted in shifts in microbial community composition, including decreases in mycorrhizal fungi, total fungi, Gram-positive bacteria, and actinomycetes. As a comparison,
non-contaminated agricultural soils were experimentally amended with zinc in the laboratory, and after 420 days these soils also showed decreases in microbial activity and decreases in mycorrhizal fungi. The soils at the zinc smelter site were remediated by addition of organic matter in the form of sewage sludge. Comparison of remediated and non-remediated soils revealed that the remediation program resulted in a reduction in soluble metal levels and some recovery of the microbial populations
Speaker Information: John Kelly, Loyola Univ. Chicago, 6525 N. Sheridan Road, Chicago, IL 60626; Phone: 773-508-7097; E-mail: [email protected]
Session Information: Tuesday, November 2, 2004, 8:10 AM-3:45 PM Presentation Start: 8:10 AM
