Impact analysis of the toxic metals emitted to agricultural soil from industrial activities in Fez area, in the frame of Life Cycle Assessment

Contamination by trace metals in agricultural soils in the Fez region are linked to irrigation water used from the Oued Fez. This one is the direct receiving environment of industrial and urban effluents that have a high pollution load in spite of treatment and risk minimization efforts. Several reports and studies in this region confirmed a state of high metallic pollution at the Oued Fez and its confluence with the Oued Sebou. The effluents of the tannery and textile industries as well as those of the metal finishing industry, present the greatest risk in this type of pollution, because of the use of some metals in their processes. This work aims to translate the metals quantities which are emitted during the industrial activities life cycle in potential impacts on water, soil and human health. The life Cycle Assessment (LCA) was adopted as multi-criteria methodology for identifying and quantifying the majority contributions related to various local industries metal emissions. In particular, there is question to analyzing the aquatic and terrestrial ecotoxicity and human toxicity. The characterization of these impacts takes into account the fate of trace metal emissions from industrial sources until their presence in water/sediment and agricultural soil through irrigation water; and their toxic effects on aquatic species and human health.The fate of metals emissions were determined by a geochemical study in the areas with different pollution states. The analysis of total concentrations and bioavailable fractions was conducted on the industrial effluents and the three environmental compartments: water, sediments and soils. The effect factor is based on the effect concentrations HC50 of the Impact2002 + database and by specifying some parameters such as the partition coefficient of trace elements, the density and the moisture content of the soil. At this stage analysis, the trace elements Cr, Ni, Cu and Zn are the major contributors to the terrestrial ecotoxicity. This is due to several causes combined or separated: high total concentrations in the soil, a greater mobility with higher bioavailable fractions and lower concentrations of toxic effect.