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Environ Monit Assess (2012) 184:54975510 DOI 10.1007/s10661-011-2356-4
Elemental contamination in urban parks of Rawalpindi/ Islamabada source identification and pollution level assessment study
Sajid Iqbal & Mohammad Wasim &
Muhammad Tufail & Mohammad Arif &
Muhammad M. Chaudhry
Received: 29 March 2011 /Accepted: 30 August 2011 /Published online: 14 September 2011 # Springer Science+Business Media B.V. 2011
Abstract The soil quality of urban parks is of vital importance as the children playing in the parks get themselves easily contaminated. A study was conducted to assess the level of elemental pollution caused by constant urbanization and industrialization, in various parks of Islamabad and Rawalpindi. The soil samples, collected from 14 urban parks of Islamabad and Rawalpindi areas, were analysed for their elemental concentrations. In each sample, 32 elements were quantified using semi-absolute k0-
instrumental neutron activation analysis and flame atomic absorption spectrophotometry. The quality of analysis was assured by analysing the International Atomic Energy Agency (IAEA) reference material IAEA-S7 (soil). The pollution level was assessed by enrichment factor, pollution load index and our suggested indicator called average toxic element concentration. The elemental concentrations measured in the parks of two cities were compared by t test. Four sources of different elements in the soils were identified by employing principal component analysis and cluster analysis. The results of multivariate techni-
ques grouped all parks into four classes. The use of enrichment factor indicated the presence of Ni at slightly higher level in all parks while the pollution load index revealed that the parks of Rawalpindi were relatively more polluted as compared to that of Islamabad. The hot spot areas of elemental concentration were closely related to high traffic conditions.
Keywords Urban parks . Heavy metals . Enrichment factor. Pollution load index . Average toxic element concentration . Principal component analysis . Cluster analysis
Introduction
Soil is a heterogeneous mixture of many substances such as air, water, inorganic and organic materials and microorganisms that occur on the land surface (Juma 2001; Sparks 2003). It is formed by the addition, loss and transfer of materials either by natural or by anthropogenic activities (Bradley and Stolt 2003). The main constituents of an uncontaminated soil include oxygen, silicon, aluminium, calcium and iron. Urban areas are characterised by unique ecological features due to adverse...