Biomonitoring of heavy metal contamination in <em>Pongamia pinnata</em> and <em>Peltophorum pterocarpum</em> growing in the polluted environment of Karachi, Pakistan


  • Muhammad Shafiq
  • Muhammad Zafar Iqbal
  • M. Saeed Arayne
  • Mohammad Athar


Determination of some of the important heavy metals like lead and
cadmium was carried out in the city environment of Karachi. Foliage
parts of two roadside trees, Pongamia pinnata (L.) Merrill and
Peltophorum pterocarpum D.C. Backer ex K. were used to carry out
such investigation. Five roadside points were selected for the study
in different parts of the city. The investigations showed that high
level of lead and cadmium was found in the foliage of P. pinnata
and P. pterocarpum, which were growing along the busy roads of the
city. The level of Pb and Cd in the foliage of the above mentioned
trees was quite high at M.A. Jinnah road as compared to Shahrahe-
Faisal, Nazimabad, Gulshan-e-Iqbal and Karachi University
Campus. Low traffic activities at the University Campus showed
lowest lead and cadmium levels in the foliage of both tree species
than the other point of the city. In this study, P. pinnata showed
more accumulations of lead and cadmium than P. pterocarpum.
This difference might be due to large surface area of the foliage in
P. pinnata that is available for exposure to any pollutants as compared
to P. pterocarpum. P. pinnata is a useful plant species in
removing different heavy metals from the urban environment of the
city. It is therefore suggested, that P. pinnata should be given more
preference for future plantation in the areas, particularly along the
busy roads and highways.