TITLE:
GIS Mapping, Biomonitoring and Distribution of Heavy Metal Concentrations Using Neem (Azadirachta indica) Bark in Makurdi Town, Benue State, Nigeria
AUTHORS:
Ada Florence Ogli, Mohammed Ahmed, Adams Udoji Itodo, Raymond Ahulle Wuana, Rufus Sha’Ato
KEYWORDS:
Heavy Metal Contamination, Spatial Distribution, Inverse Distance Weighting, Folk Medicine, Makurdi
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.11 No.7,
July
26,
2023
ABSTRACT: The present work determined the concentration and
spatial distribution of heavy metals (As, Hg, Cr, Cd and Pb) in soil samples
from Makurdi and its environs using geographic information system (GIS). The
specific objective is to produce the spatial distribution maps showing the
spatial distribution of toxic heavy metals in
the study area. Inverse Distance Weighting (IDW), a GIS technique was
used to produce dotted maps showing the spatial distribution of heavy metals in
neem bark for better visualization of contamination zones and non-contamination zones. The map
reveals few hotspot areas showing areas of high concentrations of the heavy metals investigated
which were identified in red colours, the following concentration ranges were
obtained; As (4.71 - 6.43 mg/kg), Cd (13.9 - 16.84 mg/kg), Cr (46.3 - 60.84
mg/kg), Hg (3.70 - 5.05 mg/kg) and Pb (24.02 - 31.34 mg/kg). These hotspot
areas were found close to business outlets,
fuel filling and service stations, farm sites where the application of
fertilizers and pesticides were persistent coupled with heavy traffic of
vehicles and other machinery which was associated with As, Hg, Cd, Pb and Cr
been released into the environment thus, suggesting anthropogenic activities
controlling the concentration of these heavy metals in the study areas. The
cumulative effect of these heavy metals into the barks of neem could pose as
danger, because this plant is used as herbs in folk medicine.