Assessment of Atmospheric Deposition and Spatial Variability of Trace Metals in Kandy City and Suburbs using Bio-monitoring Technique in Mosses

Lakshika Weerasundara,Meththika Vithanage

doi:10.4038/vjs.v21i1.6059

Abstract

Deposition of atmospheric Trace metals (TMs) was investigated in this study through the analysis of mosses that have been grown at nine locations within the Kandy Municipal Council area and its suburbs. Hyophila sp. moss was selected for TM analysis with referring their common availability. After cleaning, dried mosses samples were digested with conc. HNO3 in microwave digesting system. Digested samples were analysed for Al, Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb using Inductive Coupled Plasma-Mass Spectrometry (ICP-MS). Average TM concentrations in mosses, were resulted with the order of Fe>Al>Zn>Mn>Cu> Pb> Cr>Ni>Cd. The highest and lowest metal concentrations were recorded for Al and Cd as 12,150 and 0.2 mg/kg respectively. Principle factor analysis suggested two major factors; vehicular emission and geographical location, responsible for the TM concentrations in mosses. Factor analysis indicated that approximately about 73% of the TMs in the atmosphere are by the two factors whereas majority from that to be from the vehicular emission. Apart from that, trans-boundary pollution could identify as one of the major factors for TMs in Kandy. Spatial distributions are not significant for the metals that have identified as geogenic origin and others were reported with clear spatial distribution with having highest accumulations in the areas those experiencing higher traffic activities. The ecosystem risk values are still in the acceptable levels in the means of trace metals in mosses. Key words: mosses, bio-monitoring, trace metals, atmospheric deposition

Highlights

Atmospheric particulates are dispersed into the environment through either natural or anthropogenic origin
In accordance with the results shown in Weerasundara et al (2017) both geogenic and anthropogenic metal have been found in the Kandy environment whereas the geogenic metal concentrations showed elevated concentrations than that of the anthropogenic metals
Mn and Zn reported in significant concentrations in moss samples

Summary

Introduction

Atmospheric particulates are dispersed into the environment through either natural or anthropogenic origin. Industries, residential heating and traffic activities are some of major anthropogenic activities that rich with particulate emission (Cao et al, 2011, Weerasundara and Vithanage, 2015). As most of the anthropogenic activities are gathered in urban cities, the urban environments are great victims of these atmospheric pollutants (Cao et al, 2011). The atmospheric particulates which are emitted from various sources are rich with different types of atmospheric pollutants that are able to affect both human and ecosystem quality (Castillo et al, 2013). The atmospheric pollution by TMs is acknowledged in all over the world, the pollution status has increasing trend due to escalation of emission sources and monitoring and quantification of TM loads in the atmospheric deposition is a vital need in this era

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Results

Conclusion