Cd, a toxic carcinogenic
metalloid, was detected at higher concentration in urban
dust (mean; 2.3 ppm) than in industrial (1.2 ppm) and rural
(0.4 ppm) ones (p < 0.05). The higher Cd values in the urban and
industrial samples suggest that its wide use in the production of
PVC and of Cd-batteries, and as fertilizer, paints, and platting industry
(Abdullah et al., 2015).