ASSESSMENT OF HEAVY METAL CONC… ISSNAnzene online:et2616-1370

Overview

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Key numbers

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Hg (0.100 mg/kg – 0.367 mg/kg), Cr (0.117 mg/kg – 0.926 mg/kg), and Mn (0.480 mg/kg – 1.385 mg/kg) were
above the maximum permissible limits (0.04 mg/kg), (0.2 mg/kg), (0.1 mg/kg) of World Health Organisation
(WHO), and (0.0005 mg/kg for Hg) of National Environmental Standards Regulations Enforcement Agency
levels of concentrations of Hg (0.123 mg/kg - 0.345 mg/kg), Cr (0.067 mg/kg – 2.833 mg/kg), and Mn (0.702
mg/kg – 3.091 mg/kg) across the locations were also found to be above the tolerable limits. Except for nitrates
in wet season (131.36 mg/L – 1,312.15 mg/L), phosphates (0.12 mg/L – 7.86 mg/L) and organic matter (2.19%
w/w – 3.24 % w/w), dry season for nitrates (176.84 mg/L – 1,755.21 mg/L), phosphates (0.26 mg/L – 14.39
mg/L), organic matter (2.82% w/w – 3.23 % w/w) which were above WHO standards of 30 mg/L, 4.5 mg/L
and 3% w/w respectively, other results obtained for physicochemical parameters during the wet season were
The impact of solid waste on health and environment has been of 3% (Banki et al., 2019; NPC, 2023). This remarkable
Central (Table 1) in wet season (September 2021) and dry al., 2010; Opaluwa et al., 2012).
Table 1: Geographical locations of sampling sites
Table 2: Geographical positions of soil samples taken from refuse dumpsites in different geographical zones
W2 = weight of core sampler + weight of sample before oven Table 3 showed the results of concentration of heavy metals
Organic carbon and organic matter determination was carried ranged from 0.100 mg/kg in the second sampling point of
the concentrated acid medium. The excess potassium 0.123 mg/kg in the first sampling point of Tudun Abu to 0.345
(MO) was deduced from the percentage of organic carbon threshold limit of 0.04 mg/kg and 0.0005 mg/kg set by
Where N= Normality of KMnO4; metals are major components of these wastes and have been
% Organic Matter = % Organic Carbon x 1.724 (Badmus et 0.926 mg/kg of the first sampling point of Deeper Life above
al., 2014; Musa et al., 2020; Ruth et al., 2021). the maximum threshold limit of 0.2 mg/kg (WHO). While in
Electrical Conductivity (EC) 0.067 mg/kg of the first sampling point of Doma Road to
Electrical conductivity (EC) was determined from the filtrates 2.833 mg/kg of the first sampling point of Poly Guest House
obtained from the suspension for pH analysis using above the maximum threshold limit of 0.2 mg/kg (WHO). The
determined as outlined by Adewuiyi and Opasina, (2010); 1.385 mg/kg of the second sampling point of Tudun Abu
Obasi et al., (2012); NO3-, by Phenoldisulphonic acid method. above the threshold limit of 0.1 mg/kg. In dry season, the
PO42- was analyzed colorimetrically by molybdophosphoric concentrations of Manganese (Mn) range from 0.702 mg/kg
acid, while Cl- was determined by Volhard method. Sulphate of the second sampling point in Gandu to 3.091 mg/kg of the
Table 3: Concentrations of Heavy Metals of soil samples from Refuse Dumpsites at different Geographical Locations
Table 4: Physicochemical Results of Soil Samples from Refuse Dumpsites at different Geographical Locations
Sample pH Temp. EC Moisture Organic Organic TDS COD BOD DO NO3- PO42- Cl- SO42-mg/L
Sample pH Temp. EC Moisture Organic Organic TDS COD BOD DO NO3- PO42- Cl- SO42 -mg/L
In Table 4, during the wet season, the concentrations of RECOMMENDATIONS
nitrates across the sampling points range from 131.36 mg/L The study therefore recommends the followings:
1,312.15 mg/L of the first sampling point of MOWA in Bukan integrate the regular monitoring of waste disposal into its
Sidi above the threshold limit of 30 mg/L. While in the dry developmental plan and framework in order to mitigate
Doma Road to 1,755.21 mg/L of the first sampling point of Adequate measures should be put in place to create awareness
0.12 mg/L of the first sampling point of Deeper Life to 7.86 evaluation.
maximum permissible limit of 4.5 mg/L. During the dry general public about the potential environmental risks
season, the concentrations of phosphates range from 0.26 associated with the use of refuse dumpsites for farming and
the maximum permissible limit of 4.5 mg/L. The high level of ascertain the potential ecological risks of other heavy metals
season, range from 2.19% (w/w) of the first sampling point of Adewuyi, G. O. and Opasina, M. F. A. (2010).
Omgbolo Hotel to 3.24% (w/w) of the first sampling point of Physicochemical and heavy metals assessment of leachates

Methods (brief)

FUDMA Journal of Sciences (FJS)
physicochemical parameters from 20 soil samples each from selected refuse dumpsites in wet and dry seasons
were determined using Atomic Absorption Spectrophotometer and Association of Official Analytical Chemists
FUDMA Journal of Sciences (FJS) Vol. 8 No. 6, December (Special Issue), 2024, pp 152 - 162 152
generated daily, with indiscriminate dumping of these solid digestion apparatus, filtration apparatus, glass bottles,
wastes in open places (Besufekad et al., 2020). Poor waste polythene bags, plastic containers, sample labels and markers,
among the key factors responsible for the multiple problems trowel, core sampler), thermometer, pH meter, conductivity
uptake. Vegetables absorb these metals from the ground, as spectrophotometer, Atomic Absorption Spectrophotometer,
metals and physicochemical parameters from soil samples in between longitude 7o and 9o 37’E of the Greenwich meridian
FUDMA Journal of Sciences (FJS) Vol. 8 No. 6, December (Special Issue), 2024, pp 152 - 162 153
Sample collection Tudun Amba, Gandu and Tudun Abu. Each sampling unit
Soil samples (wastes) were collected at 0-15 cm below the from the refuse dumpsites was 50 m, 100 m apart and the
dumpsites and twelve (10) control sites across the Lafia individual units of three samples were taken from each
No. of samples collected
Sample Preparation dumpsites were determined. Results obtained were expressed
Composite samples made by mixing individual sample units as mean ± standard deviation of three replicate measurements.
for analysis. The samples were air dried for 48 hours, ground With the use of Global Positioning System meter (GPS
other materials. Samples at 50 m, 100 m from each refuse sampling points were measured and the results were recorded

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Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.

Commit	Date	Change	Description
b01ec52c	2026-08-04	major	2 sections added
d49e450f	2026-08-03	major	5 sections added; narrative text revised