ASSESSMENT OF MOSS SPECIES AS BIOMONITORS OF ATMOSPHERIC POLLUTANTS IN SOME TOWNS OF NORTH-WESTERN NIGERIA.
ASSESSMENT OF MOSS SPECIES AS BIOMONITORS OF ATMOSPHERIC POLLUTANTS IN SOME TOWNS OF NORTH-WESTERN NIGERIA.
No Thumbnail Available
Date
2015-06
Authors
ABDULLAHI, SA’IDU
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The development of industry, urbanization and increase in vehicular emissions in Nigeria has resulted in the contamination of the environment by heavy metals and other pollutants. Air borne heavy metals and other pollutants (including NOX and SO2) enter the ecosystem where they circulate and, depending on their concentration and toxicity, pose a greater or smaller threat to the components of these ecosystems.Thus, this work is designed tostudy the use of moss species as biomonitors of air pollutants in some towns of North-West Nigeria.Moss sampling was carried out during the dry and wet seasons from various substrates. The distribution/occurrence of the plants on the various substrates was calculated.Foreign materials adhering to the moss samples were removed washed with double-distilled water and oven dried at 60° C for 48 hours. They were then ground in a porcelain mortar to obtain fine particles and stored in polythene bags ready for analyses.Heavy metal contents (Co, Ni, Cu, Cd, Pb, Cr, and Zn) in the samples were determined using Fast Sequential Atomic Absorption Spectrometer (Varian AAS 240FS).Determination of NO3 and NO2 were done by steam distillation while that of SO2 was doneturbidimetrically.ANOVA was used to test for differences in individual concentrations in the species and the different locations, Duncan‟s Multiple Range Test (DMRT) was used to separate the means in case they are significantly different and T-test used to determine seasonal variability of mean levels of pollutants in the moss species.A total of about 144 samples were collected throughout, representing eight (8) different species of moss withHyophilacrenulatahaving the highest percentage of occurrence.Kano was having the highest mean concentrations of 4 of the 7 heavy metals analyzed which are Cu, Cd, Cr and Pb.Kano had the highest concentrations of almost all the major pollutants, while Ringim had the least of the majority.Ni, Cu, Cd, Cr and Co showed
relatively higher accumulation values in the wet season than the dry season, while Pb and Zn had higher values in the dry season but statistically not significant in all cases.From the study, it can be said that out of the different mosses studied, three speciesBryumcoronatum, Fissidensgrandifolius and Hyophilacrenulata were precise and useful bioindicators/biomonitors of heavy metals in the studied locations. Among them B.coronatumis the good accumulator of majorityof themetals. SO2 accumulation was better up in Barbulalambarenensisand Erpodiumpobeguini, while Fissidensgrandifoliuswas better in accumulating NO2 and NO3.There is no significant variation in accumulation of all the studied pollutants in the moss plants between wet and dry seasons. Heavy metals (Co, Ni, Cu, Cd, Pb, Cr, and Zn) as well as SO2, NO2 and NO3 were present in the environments of all the study locations, at the time of sampling. The results provide baseline information for regional atmospheric pollution monitoring using moss species as effective biomonitors in the studied locations.
Description
A THESIS SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES,AHMADU BELLO UNIVERSITY, ZARIAIN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARDOF AMASTER OF SCIENCE DEGREE IN BOTANY.
Keywords
ASSESSMENT,, MOSS,, SPECIES,, BIOMONITORS,, ATMOSPHERIC,, POLLUTANTS,, SOME,, TOWNS,, NORTH-WESTERN,, NIGERIA.