Trends of heavy metals contamination in various micro-environments of district Peshawar

Abstract

Understanding trends of heavy metals contamination in the dust of different micro-environments is significant for health risk assessment, urban planning in cities and pollution control. Concentrations of six heavy metals were measured by taking n=5 dust samples from twenty micro-environments and their further amalgamation forming four zones on the basis of similarity. All the samples were air-dried, ground, passed through 30 mesh sieve and digested with aqua regia and HF. The samples were analyzed in atomic absorption spectrometry for Pb, Zn, Cr, Cu, Cd and Ni. Assessment of contamination in each zone was done by various methods: Zone composition of heavy metals, Analysis of Variance, geo-accumulation index and health risk assessment for each trace metal. Geo-accumulation index was of the class 1 for all the elements of all the four zones i.e. the dust was uncontaminated to moderately contaminate. Health risk via. Ingestion to children was evaluated and found to be non-significant for most of the heavy metals. Zinc read as the highest concentration trace metal in all the four zones.