TITLE:
Investigating the Distribution of Selected Major and Trace Metals in Lithogenic Environment near Cement Factory, Mekelle, Ethiopia
AUTHORS:
Samuel Estifanos
KEYWORDS:
Metals; Geochemical Extraction; Cement Factory; Dust Emission; Factor Analysis
JOURNAL NAME:
Journal of Environmental Protection,
Vol.5 No.2,
February
28,
2014
ABSTRACT: Sixteen physicochemical
parameters including four major and ten trace metals were analyzed for seven
top soil and six top stream sediment samples collected around the vicinity of
cement factory in Mekelle, Ethiopia. Water and aqua regia extraction techniques
were deployed to determine the water soluble and near total concentration of
the metals in the samples. Water extraction results verified the magnitude of
loading of the metals from anthropogenic sources. The mean values of the water
soluble metals are found to exceed the reference values except for Ca and Zn in
both lithogenic media indicating the severity of pollution. Spatial
distribution of the metals suggested that cement factory dust and traffic
emissions represent the most important pollutant sources for the investigated area. The mean proportion of the major and trace
metals in the water soluble phase of soil can be put on a descending order as:
Mg (57.76%) > Fe > Ca > K > Na > Mn (3.77%) and Mo (53.17%) > Cu > Co > As > Ni > Zn > Pb > Cr (5.02%) respectively. The order of
major metals is almost reverse in the case of the stream sediment with slight
difference in the order of the trace metals. Factor analysis has revealed that
the first factor represents the contribution of metals (Mn, Cr, As, Co, Zn, Na,
K, Cu, Pb and Ni) from local anthropogenic activities, whereas the second
factor represents the contribution of metals (Na, Fe, Cu, Pb, Ni, Ca, As, Co,
Zn and Mo) from both lithogenic and anthropogenic origins. Third factor
consists of Ca, Mo, Mg, and Fe from geogenic source of the local geology. It is
spatially evident that the cement dust emission has an impact on the soil’s Cr,
Co, Mo and Ni content which drastically decreases downstream. The spatial
pattern of Cu, Pb, As, Zn and Co shows significant association with the cement dust and loadings from the
traffic movement on the road.