The purpose of this paper is to establish some acceptable trends in the contamination of roadside vegetation and to define a safety limit regarding the effects of metal contamination arising from various toxic metals deposited on leaves of the plants and in the bulk of the fruits.
Distribution of essential and non‐essential elements on the surface of leaves and in bulk of fruits of specific areas of Multan (Pakistan) was estimated and correlated with World Health Organization (WHO) standards. The metal concentrations are expressed as X ± SD for triplicate sub samples with the SD of ± 1.0‐1.5 per cent. The maximum metal levels in bulk of various fruits were calculated for FE, followed by Cu, Zn and Co.
In samples from roadside leaves Fe (823 mg/kg) was found to be the dominant metal, whereas the observed threshold level was found for Co (17.25 mg/kg). The non‐essential elements in various fruits, the Cr was found to be the dominate (16 mg/kg) on mean basis as compared with other metals in fruits. The increasing order of non‐essential metals on the surface of roadside leaves was Li < Ni < Sr < Pb < Cr. The results revealed that metal concentration decreases with increase in distance from roadside (10, 30 and 50 m) with negative correlation coefficient.
This paper shows that the metals concentration in case of all fruit samples fall within the permissible safe limit, whereas the metal concentrations on the surface of roadside leaves were found to surpass the safe limits laid down by the WHO. It is consequently suggested that edible portions of vegetation and fruits near highways should be consumed cautiously.
