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3
rd
International Conference on
3
rd
International Conference on
Ecology, Ecosystem and Conservation Biology
Microbial Ecology & Eco Systems
&
March 18-19, 2019 | Chicago, USA
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JOURNAL OF ECOSYSTEM& ECOGRAPHY 2019, VOLUME 9 | DOI: 10.4172/2157-7625-C1-044
SCIENTIFIC TRACKS
|
DAY 1
Assessement of heavy
metals in urban aerosol
samples in Sebele,
Botswana
Sello A Likuku, Khumoetsile T Mmolawa,
and
Gilbert K Gaboutloeloe
Botswana University of Agriculture
and Natural Resources, Botswana
B
ush fires and dust in the
dry winter months establish
moderately high background
levels of aerosols. Emissions
into the atmosphere by
copper mines, coal mines,
and vehicular emissions are
all possible sources of air
pollution with heavy metals.
Although there has been
assessment and monitoring
of heavy metals and their air
pollution in other countries
such as Brazil, Europe,
and America, there is little
documentation about the
concentration of heavy metals
in aerosols in Botswana.
A total of 63 Aerosol
samples were collected at
the Botswana College of
Agriculture and were analyzed
for concentrations of Al, Co,
Cu, Fe, Pb, Mn, Ni, and Zn
infiltrate using a Flame Atomic
Absorption Spectrometer
(Varian SpectrAA 220 FS).
Statistical receptor models
were applied to investigate
potential sources of the
studied metals. Data exhibits
enhanced enrichments of Zn
(EFg=76), Al (EFg=14391),
Co (EFg=19), Cu (EFg=5), Pb
(EFg=3) and Ni (EFg=2), which
was attributed to contributions
from non-crustal sources,
whereas Mn and Fe (EFg < 2)
were attributed to crustal
origin, such as airborne dust.
Data were subjected to factor
analysis (FA) twice. From FA-1,
two Principal Components (PC)
were revealed. PC-1 showed
high positive loadings of Pb,
Zn, Ni, and Al, whereas PC-2
had loadings for Fe and Mn.
On the other hand, FA-2 had
three principal components.
PC-1 from FA-2 showed strong
loadings for Cu, Fe, and Mn.
FA-2 had strong loadings
of Pb, Al, and Zn, whereas
loadings for PC-3 were
comprised of Ni and Co. The
difference between loadings
of FA-1 and FA-2 suggested
possibilities of mixed origins
of the studied metals. Finally,
air mass back-trajectory
analysis showed that during
the sampling period, there
were only 5 cluster groups
that represented significantly
different transport pathways
of aerosol samples, where only
Zn and Ni mean concentrations
revealed a dependence on
the geographical origin of
aerosol samples. Results of
the analyzed concentrations
of Al, Co, Cu, Fe, Pb, Mn, Ni
and Zn in aerosol samples
showed that the presence of
Fe and Mn in the atmosphere
in the ambient air of Sebele
is mainly due to contributions
from lithogenic sources. Pb,
Ni, Co, Al, and Zn exist because
of anthropogenic sources,
whereas, Cu, exist because