Environmental contamination by heavy metals and radioactive elements in Wadi Nasab and its surroundings, southwestern Sinai, Egypt

الملخص EN

Wadi (Valley) Nasab (WN) and its surroundings, is an area of mining located at the southwestern Sinai, Egypt for some heavy metals and radioactive elements from lower carboniferous.

This activity represent a source of environmental contamination.

This contamination is the main target of this study.

Ore material, solid wastes and soil samples were collected from 10 stations.

Whereas, plants samples were collected from two types of herb weeds (i.

e.

, Zygophyllum siplex and Haloxylon salicornicum) from WN and its surroundings southwestern of Sinai.

The original ore material is chemically consisted of around 50% SiO2, 10.6% Al2O3, 10.2 Fe2O3, 13% (CaO + MgO) and around 10% loss on ignition.

This figure means high carbonate and total iron contents.

The mineralogic constituents of solid waste are consisted of Quartz, Kaolinite, Jarosite and Gypsum.

The milling waste contains 60.2% SiO2, 6.8% Al2O3, 9.4% Fe2O3, 4.7% (CaO + MgO) and 14.8% loss on ignition.

The picture of some trace elements is as follow; Cu is 2900 ppm in ore materials and 359 ppm in milling waste.

In the same order, Zn is 1865 and 92 ppm, Th is 14 and 26 ppm, U is 346 and 184 ppm, Ra226 is 135 and 179 Bq/ kg.

This picture of ore material and milling waste is reflected on the soil profile after the flash flood.

The degree of contamination is pronounced in the upstream water of W.

Nasab and decrease in the direction of downstream.

Thorium (Th) ranged from 5 to 13 ppm at the upstream and from 4 to 5 ppm in the downstream.

On the other hand, U ranged from 5 to 9 ppm in the upstream and from 2 to 7 in downstream.

The contamination effect is also clear in two types of Herb weeds of WN.

Uranium in roots of (Zygophyllum siplex) plant, ranged from 4 to 6 ppm while in roots of (Haloxylon salicornicum) plant was not detected.

Also, it was not detected in the vegetable parts of the two herb plants and Th was not detected in roots and the vegetable parts of the two herb plants.