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

zinc; had very low pH; and were determined to be phytotoxic to native vegetation (Kapustka
et al., 1995). The elevated soil arsenic and metal concentrations occurred despite significantly
lower organic matter concentrations in affected soils relative to reference sites (Galbraith et al.,
1995). Line-transect measurements indicated that affected sites had an average of 6.9 species per
10-m of transect, compared to 20.3 species per 10-m in the reference areas. More than 60% of
the reference sites supported coniferous (58%) or deciduous (3%) forest communities, whereas
less than 1% of the affected sites retained functioning forest stands. Abundant dead timber and
stumps confirmed that the affected sites were once as forested as the reference sites. Affected
grassland sites were also less diverse and had higher abundances of invasive species than
reference grasslands. More than 50% of the affected sites were classified as bare ground. The
occurrence of bare ground was significantly correlated with the phytotoxicity scores derived by
Kapustka et al. (1995), indicating a link between phytotoxicity and the loss of vegetation in the
affected area.
Because of the plant community changes near the Anaconda smelter, the vertical diversity
of habitats in the affected ecosystems decreased, with only shrubs and soil remaining as viable
habitats. Galbraith et al. (1995) also used the Bureau of Land Management’s habitat evaluation
procedure (HEP) to estimate habitat suitability indices (HSI) for two indicator species, marten
(Martes americana) and elk (Cervus elaphus). The HSI value ranges from 0 (poor habitat) to
1 (ideal habitat). In sites affected by the Anaconda smelter, HSI values for marten averaged 0.0,
compared to 0.5 to 0.8 for the reference sites. For elk, affected sites had an average HSI of 0.10,
compared to 0.31 at reference sites.
Similar observations were made in the area surrounding Palmerton, Pennsylvania, where
two zinc smelters operated between 1898 and 1980. Soils in the area were enriched in Cd, Zn,
Pb, and Cu, with concentrations decreasing with distance from the smelter sites (Beyer et al.,
1985; Storm et al., 1994). Smelting was determined to be the principal source of Pb in soils in
residential and undeveloped areas around Palmerton (Ketterer et al., 2001), which lies on the
north side of a gap in Blue Mountain, a ridge running roughly east-west in east-central
Pennsylvania. Much of the north-facing side of Blue Mountain within 3 km of the town is bare
ground or sparsely vegetated, whereas the surrounding natural landscape is predominantly oak
forest (Sopper, 1989; Storm et al., 1994). Biodiversity in affected areas is considerably lower
than at reference sites, a pattern attributed to emissions from the smelters (Beyer et al., 1985;
AX7-96