PW18 Field Biological Monitoring of Ecosystem Impairment
Exhibit Hall
8:00 AM - Wednesday
(PW285) Assessing the ecological risks of metals in a restored mountain habitat in southeastern Pennsylvania.
Ludwin, D1, Iannuzzi, T1, Rigg, D1, Thelen, J1, Shisler, J1, Armstrong, T1, 1 BBL Sciences, Annapolis, MD, USA
ABSTRACT- Atmospheric deposition and waste disposal from zinc smelter operations occurring between 1898 and 1980 and other historical impacts near the Borough of Palmerton, Pennsylvania, have resulted in the reduction or elimination of flora and habitat on areas of Blue Mountain. In the mid-1990s, approximately 1000 acres of the Mountain were restored, starting with the experimental application of an amended biosolids sludge. The sludge material, a combination of aerobically digested sewage sludge, fly ash, and burnt lime (CaO2) was applied to the Mountain to prepare the surface for re-growth of vegetation and subsequent development of viable wildlife habitats. Today there are at least 3 habitat types on the Mountain that support wildlife: grasslands, scrub-shrub, and early successional forest. In the Fall of 2003, we collected data and conducted an ecological risk assessment to assess the likelihood that residual risks exist from metals in soils and vegetation to wildlife communities that now inhabit the restored part of the Mountain. We also examined the issue of potential metals enrichment of the leaf litter and surface soils via cycling from deeper soil layers. Samples (test and reference) of surface soils, leaf litter, vegetation, and terrestrial invertebrates were collected. The samples were analyzed for arsenic, cadmium, copper, lead, and zinc. The observed metal concentrations are generally highest in soil samples, and metals are not biomagnified in biota. The data do not show any evidence of metals enrichment from subsurface soils. The conceptual site model identified potentially complete exposure pathways for several types of ecological receptors, including herbivores, insectivores, and carnivores. The results of the risk analyses suggest that there are no residual risks from metals. This, coupled with the fact that the ecosystem has been re-colonized by a diverse and abundance array of flora and fauna, suggests that the restoration efforts have been successful.
Key words: soil, metals, vegetation, risk assessment