Introduction:
Emissions from a variety of air particulate sources have resulted in
atmospheric pollution that, in turn, has produced serious problems, causing
irreversible reactions in the environment and hence is posing a major threat to
our very existence. Aim: Identify monthly variations of particulate matter mass
concentrations in air, the contribution of each size fraction (coarse and fine)
to PM10 levels, and the contributions from natural and anthropogenic
sources. Methodology: PM10 ambient air
particulates in two size fractions being the coarse (PM10-2.5) and fine (PM2.5)
were sampled. Heavy metals and carbonaceous compounds [organic carbon (OC) and
elemental carbon (EC)] concentrations were determined. Enrichment factor (EF)
was used to identify species of crustal and non-crustal origin in ambient air
particulates. The identified elements were used to develop fingerprints for a
number of particulate sources. Results:
The mean coarse and fine particulate levels obtained were 89.2 g/m3
and 21.6 g/m3 respectively. The maximum and minimum levels occurred in
February (dry season) and July (rainy season) respectively. Soil dust was found
to be the major source of particulates in the two size fractions (coarse and fine).
The sulphur contents in Harmattan (cold dry winds) dust in the dry season was
found to be predominantly in the coarse fraction. EF was used to identify
species of crustal and non–crustal origin in ambient air particulates. The
Enrichment Factor values for the elements Cr, Cu, Zn, Pb and Br showed that
they were mostly from anthropogenic sources. Conclusion: This study emphasizes the
significant impact of seasonal variations on particulate levels. The problem
with air quality is seen to be greatest during the Harmattan when cold dry
winds blow soil dust particulates across West Africa.
Author(s) Details
Francis G. Ofosu
National Nuclear Research Institute, Ghana Atomic Energy Commission, Accra, Ghana.
View Book :- http://bp.bookpi.org/index.php/bpi/catalog/book/189
Author(s) Details
Francis G. Ofosu
National Nuclear Research Institute, Ghana Atomic Energy Commission, Accra, Ghana.
View Book :- http://bp.bookpi.org/index.php/bpi/catalog/book/189
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