Heavy metal air pollution study, using a Moss Bio Monitoring technique

Abstract

Air pollution is increasingly becoming a problem in developed and developing countries. As a corrective measure, constant air monitoring has been done using conventional techniques which are costly and time consuming hence the need for cheaper and affordable methods. Of recent, biomonitoring has emerged as an effective alternative method. The aim of this study was to investigate heavy metal air pollution in the environment using Moss. Moss are lower plants that can provide a surrogate and time-integrated means of measuring elemental depositions from the atmosphere to terrestrial systems. Atmospheric deposition of heavy metals Chromium (Cr), Copper (Cu), lead (Pb), and Zinc (Zn) was studied at the University of Zimbabwe. 17 samples of Moss were hung on sites selected by a systematic grid sampling method, during the summer of 2016. The concentrations of heavy metals were determined by Atomic Absorption Spectroscopy (AAS). The concentrations were expressed as Relative Accumulation Factors (RAFs). The results showed the concentration order of deposition as Cu > Cr > Zn > Pb and that Zn deposited uniformly. Although the distribution patterns of Cr and Cu were similar, Pb and Zn had their own patterns; these results suggested that the source of heavy metal could be from traffic related air pollutants.