This research investigated the effectiveness of phosphorus (P) and organic
matter (OM) as possible in situ remediation techniques for metal contaminat
ed soils. The study was designed to determine the bioavailability of ph, Zn
, and Cd individually and in combination to the earthworm Eisenia fetida in
an artificial soil amended with varying levels of P and OM, A toxicokineti
c approach using bioaccumulation factors and uptake rate coefficients was u
sed to assess the bioavailability of the heavy metals. Overall, earthworms
in P-amended soils showed significantly reduced Pb levels in the individual
and mixture experiments, while Zn and Cd bioavailability was not reduced.
X-ray diffraction analyses indicated that pyromorphites were formed with P
amendment, thereby reducing the solubility and bioavailability of Pb within
the soil. In contrast, the OM soil amendments increased bioavailability of
Pb in the individual experiment and decreased it in the mixture experiment
. The results of this study suggest that P amendments may be a viable techn
ique to remediate Pb contaminated residential soils and that earthworm bioa
ssays represent a biologically relevant measure of metal availability in so
il.