The analysis of the horizons of 12 soil profiles confirm occasionally signi
ficant levels of Cd, Pb and Zn contamination in the areas surrounding two l
ead and zinc smelters in the North of France. A pedological approach enable
d the original Cd; Pb and Zn content of the horizons to be estimated, based
on physico-chemical characteristics of soil unaffected by contamination. T
he main contamination was found in the upper 20-30 cm. Traces of Cd and Zn
contamination were found at a depth of around 2 m. The mobility of the meta
ls may be classified in the following order: Cd >> Pb greater than or equal
to Zn. The concentration profile of a metal seems insufficient to evaluate
its movement as the metal could have been leached beyond the contaminated
horizons. The depth reached by the metals increases with their concentratio
n in the surface horizon; a decrease in pH and an increase in sand content
seem to facilitate their movement. The depth reached by Zn increases with t
he organic carbon content in the surface horizon. Earthworm galleries act a
s paths via which metals migrate downwards (C) 2000 Elsevier Science Ltd. A
ll rights reserved.