Abderrezak KRIKA¹, Oualida RACHED¹ & Gijs DU LAING^2
1Mentouri University, Faculty of Nature and Life Sciences, Laboratory of Biology and Environment, Route Ain El Bey, 25000 Constantine, Algeria, e-mail: ab.krika@yahoo.fr
² Ghent University, Department of Applied Analytical and Physical Chemistry, Laboratory for Analytical Chemistry and Applied Ecochemistry, Coupure Links 653, Gent B-9000, Belgium

ASSESSMENT OF ATMOESPHRIC LEAD CONTAMINATION OF BANKS SOILS USING SOILS TAMARISK GROVE. CASE STUDY OF THE KEBIRRHUMEL (ALGERIA)

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In order to know the role of the tamarisk grove in the soil contamination by lead (Pb) fallout, ten stations were randomly selected along the Kebir-Rhumel wadi which skirts a heavy traffic road. In each site,the sampling stations were chosen so as to contain a vegetation plot nearby a bare plot. All the stations were localized on the road side. Two soil’s samples were taken in the middle, the road and wadi side of each  plot.Tamarisk leaves were the object of an average sampling. Pb concentration was measured, by (ICP-OES) inwashed (0.53 μg.g^-1) and unwashed leaves (1.23 μg.g^-1), and in total extracts of soils (18.0 μg.g^-1), whichwere also the object of organic matter (OM), pH, electrical conductivity (EC), total CaCO₃, cation exchangecapacity (CEC) and particle sizes analysis. Significant differences were noted between washed andunwashed Pb leaves contents, suggesting an atmospheric contamination source, apparently from the roadtraffic. Pearson correlation coefficients indicate that total Pb soil contents were significantly and positivelyrelated to OM (3.30 %) and clay (10.20 %) in vegetation plots, and to pH (7.82), CEC (17.60 cmol⁺.kg^-1)and silt (30.90 %) in the bare plots. Analysis of variance (ANOVA) and Scheffe’s test reveals Pb, OM andclay contents in vegetation plots (especially in the middle of tamarisk grove) are significantly greater than inbare plots. The results show that the tamarisk grove, through the generated OM rates and the clay catching,would allow the retention of Pb in the soils, thus its mobility will decrease towards the stream water.