normalizer’s baseline concentration. For the spatial representation
of EF of heavy metals in the soil (Fig. 3), Spatial Analyst1, an
extension of ArcView3.21 software was used. The calculated
values of EF for each of the sampling location were spatially
interpolated by the method of inverse distance weight (IDW) to get
a surface with varying intensities of color/shades, representing
variation of EF between any two sampling locations.
Single factor pollution indices (PI) and the pollution load index
(PLI) were calculated for every sample to investigate the level of
pollution of the urban soils of Karachi.