Air Quality Criteria for Lead Volume II of II - (NEPIS)(EPA) - US ...

Sopper, 1989). The history is complicated, however, by the land use history of the area.
Logging and fire in the early 20th century may also have played a role in the changes in the
terrestrial ecosystems (Jordan, 1975). Extensive logging occurred after the smelters began
operation, suggesting that some of the logging may have been salvage logging in affected areas.
Regardless, the smelter emissions appear to have inhibited the regrowth of ecosystems compared
to those in nearby unaffected areas. As in Anaconda, MT, the changes in the structure and
function of the Palmerton ecosystem changed its suitability as a habitat for fauna that would
normally inhabit the area. Storm et al. (1994) did not find amphibians or common invertebrates
in two study sites nearest to the smelters. In the larger study area, they documented elevated
concentrations of Pb, Cd, Cu, and Zn in tissues of species ranging in size from red-backed
salamanders (Pletheron cenereus) to white-tailed deer (Odocoilius virginianus).
Metal pollution around a Pb-Zn smelter near Bristol, England has not resulted in the loss
of oak woodlands within 3 km of the smelter, despite significant accumulation of Pb, Cd, Cu,
and Zn in soils and vegetation (Martin and Bullock, 1994). However, the high metal
concentrations have favored the growth of metal-tolerant species in the woodland.
The effects of Pb and other chemical emissions on terrestrial ecosystems near smelters
and other industrial sites decrease downwind from the source. Several studies using the soil
burden as an indicator have shown that much of the contamination occurs within a radius of
20 to 50 km around the emission source (Miller and McFee, 1983; Martin and Bullock, 1994;
Galbraith et al., 1995; Spurgeon and Hopkin, 1996a; see also Section AX7.1.2). For example,
the concentration of Pb in forest litter declined downwind from a Pb-Zn smelter near Bristol,
UK, from 2330 to 3050 ppm in a stand 2.9 km from the smelter to 45 to 110 ppm in a stand
23 km from the smelter (Martin and Bullock, 1994). Thus, while sites near point sources of Pb
may experience profound effects on ecosystem structure and function, the extent of those effects
is limited spatially. Elevated metal concentrations around smelters have been found to persist
despite significant reductions in emissions (Hrsak et al., 2000). Most terrestrial ecosystems are
far enough from point sources that long-range Pb transport is the primary mechanism for Pb
inputs.
AX7-97