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

A literature search and review was conducted to identify critical papers published since
2002. Effects on earthworms and other invertebrates observed in studies conducted since the
1986 Lead AQCD are similar to those reported previously: mortality and decreased growth and
reproduction (Lock and Janssen, 2002; Davies et al., 2002; Rao et al., 2003; Bongers et al., 2004;
Nursita et al., 2005; U.S. Environmental Protection Agency, 2005b).
The literature search completed for terrestrial invertebrate Eco-SSL development
identified 179 papers for detailed review, of which 13 met the minimum criteria for further
consideration (U.S. Environmental Protection Agency, 2005b). Most of the 18 ecotoxicological
endpoints that were further evaluated measured reproduction or survival as the ecologically
relevant endpoint. Four of these, representing one species under three different pH test
conditions were used to develop the Eco-SSL of 1700 mg/kg soil (Table AX7-1.3.5).
Table AX7-1.3.5. Invertebrate Toxicity Data Used to Develop the Eco-SSL
Invertebrate Species Soil pH
Collembola
(Folsomia candida)
% Organic
Matter Toxicity Parameter
AX7-82
Pb in Soil
(mg/kg dw)
6.0 10 MATC 1 (reproduction) 3162
Collembola 4.5 10 MATC (reproduction) 3162
Collembola 5.0 10 MATC (reproduction) 894
Collembola 6.0 10 MATC (reproduction) 894
Geometric Mean 1682
* MATC = Maximum Acceptable Threshold Concentration, or the geometric mean of the NOEC (no-observedeffect
concentration) and LOEC (lowest-observed-effect concentration).
Source: U.S. Environmental Protection Agency (2005b).
In a study designed to test the toxicity of Pb to the earthworm Eisenia fetida, Davies
et al. (2002) found that the 28-day LC50 (± 95% confidence intervals) for Pb in soils
contaminated with Pb(NO3)2 was 4379 ∀ 356 mg/kg. Twenty-eight day EC50 values
(±95% confidence intervals) for weight change and cocoon production were 1408 ∀ 198 and