Abstract:
This study presents a picture of occurrence of heavy metals (Pb, Cd, Cu, Cr, Co, Fe, Ni, Zn) in some selected
valuable herbal drugs (G. glabra, O. bracteatum, V. odorata , F. vulgare, C. cyminum, C. sativum, and Z.
officinalis) purchased from three different zones (southern, eastern, and western) of Karachi city using atomic
absorption spectrophotometer. Heavy metal concentrations in these drugs were found in the range of: 3.26-
30.46 for Pb, 1.6-4.91 for Cd, 0.65-120.21 for Cu, 83.74-433.76 for Zn, 1.61-186.75 for Cr, 0.48-76.97 for Ni,
5.54-77.97 for Co and 65.68-1652.89 µg/g for Fe. Percentage of heavy metals that were found beyond the
permissible limits were: 71.4% for Pb, 28.51% for Cd, 14.2% for Cu, and 9.5 % for Cr. Significant difference
was noticed for each heavy metal among herbal drugs as well as their zones of collection using two way
ANOVA followed by least significant (LSD) test at p<0.05.Purpose of this research is to detect each type of
heavy metal contaminant of herbal drugs by environmental pollution, as well as to highlight the health risks
associated with the use of such herbal drugs that contain high levels of toxic heavy metals.
