Anal. Methods Environ. Chem. J. 5 (1) (2022) 5-21
Research Article, Issue 1
Analytical Methods in Environmental Chemistry Journal
Journal home page: www.amecj.com/ir
AMECJ
Determination of pollutions in the surface of water samples
from Ogbajarajara river, Nigeria by spectrophotometer and
atomic absorption spectrometry before evaluation of health
risk assessment
Stanley Chukwuemeka Ihenetu a,*, Victor Obinna Njokua, Francis Chizoruo Ibea, Gang Lib,
Arinze Chinweubac and Christian Ebere Enyoha,d
a Department of Chemistry, Faculty of Physical Sciences, Imo State University, P.M.B 2000 Owerri, Nigeria
b CAS Key Laboratory of Urban Environmental and Health, Institute of Urban Environment, Chinese Academy of Science,
1799 Jimei Road, Xiamen 361021, China
c Chemistry Department, Chukwuemeka odimegwu Ojukwu University Uli, Anambra Nigeria
d Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 8570-338, Japan
ABSTRACT
Determination of environmental pollution in the surface water is very
important. So, in this study, determination, and health risk assessment
were evaluated. The pollutions such as anions, cations, and heavy
metals were analyzed in surface water by photometer spectrometry
and atomic absorption spectrometry (AAS). Other parameters such as
pH and TDS were determined. The results showed us, the electrical
conductivity (EC) in this study falls between 100.68 ± 1.0 - 194.74
±1.4 μs cm-1 in the dry and wet season. The pH value in this study for
the two seasons varied from 5.57±0.22 to 5.73±0.28 which shows a
little acidity. In the current study, TDS for wet and dry seasons goes
from 122.17±1.74 mg L-1 to 63.80±0.86 mg L-1. This may conceivably
be a sign of typical pollution from the runoff of soils in the study area.
The high phosphate levels in both wet and dry seasons are recorded
from 60.74±0.61 to 60.27±0.38 mg L-1 in both seasons. Iron values
observed range from 8.42±0.06 to 6.28±0.11 mg L-1 in the wet and dry
season, Cu was recorded between 0.08±0.01 - 0.07±0.01 mg L-1, Mn
recorded from 0.07±0.01 to 0.06±0.01 mg L-1, Zn recorded between
2.29±0.09 - 1.15±0.09 mg L-1, and Pb recorded from 0.69±0.09 to
0.40±0.18 mg L-1 while Cd and Ni were not detected in the study.
Water quality index (WQI) values were determined as 549 for wet and
328 for the dry season, the hazard indices for both seasons are below
one. The outcomes in this present study showed that the level of Pb in
the surface water could present a carcinogenic risk to both adults and
children. All heavy metals results were validated by electrothermal
atomic absorption spectrometry (ET-AAS).
Keywords:
Heavy metal,
Environment,
Pollution,
Surface water,
Spectrophotometer,
Atomic absorption spectrometry
ARTICLE INFO:
Received 19 Nov 2021
Revised form 21 Jan 2022
Accepted 15 Feb 2022
Available online 30 Mar 2022
*Corresponding Author: Stanley Chukwuemeka Ihenetu
Email: ihenetustanley@yahoo.com
https://doi.org/10.24200/amecj.v5.i01.162
------------------------
1. Introduction
As a universal solvent, water exists as a solid,
liquid, and gaseous state. Water is mostly used in
a liquid state. Since water is crucial for all known
types of life, ensuring our water is clean and
preserved should be the most signicant and head
for this present generation and the next generation
to come [1]. Water can be viewed as a chemical
substance that is fundamental for all known types
of life. So, the pollution in water must be analyzed
6Anal. Methods Environ. Chem. J. 5 (1) (2022) 5-21
by analytical methods [2]. For the most part,
surface waters comprise streams, rivers, reservoirs,
lakes, and wetlands. Stream is applied to epitomize
other streaming surface waters, beginning from
c/reeks to the huge rivers [3]. Water pollution is
a serious biological and chemical hazard. At the
point when water is polluted, it then represents an
unsafe impact on all creatures and the wellbeing of
humans. At the point when poisonous constituents
break down in waterways of each kind like oceans,
lakes, and rivers, the water becomes polluted.
Poisons consistently defame the surface water,
which stands a genuine risk to families that use the
polluted water.
Recently. The researchers used supported liquid
extraction (SLE), the micro solid-phase extraction
(MSPE), liquid-liquid microextraction (LLME),
(liquid-liquid extraction) LLE, Liquid-phase
membrane extraction (LPME) for metal, pesticides,
carboxylic acids, and phenol in water matrixes. Also,
many metals and VOCs were determined by different
ionic liquids and adsorbents. Cloud point extraction
(CPE) has been utilized for the preconcentration
of cobalt, mercury, and nickel, after the
arrangement of a complex with 1-(2-thiazolylazo)-
2-naphthol (TAN), and later examination by
ame atomic absorption spectrometry utilizing
octylphenoxypolyethoxyethanol (Triton X-114)
as surfactant [3,4]. The inhabitants of this area
depend on the Ogbajarajara River [Og] for their
domestic and recreational purposes without
proper knowledge of the river water quality and
possible health implications. The introduction
of surface water pollution in rural areas is due to
different anthropogenic activities villagers do on
the surface water and the washing away of surface
soil directly to the surface water after manures are
applied straightforwardly on the farmland. Quick
urbanization leads to rigorous anthropogenic
activities and the consumption of resources and
energy in urban areas [4]. Individuals from these
communities in Nwangele Local Government
rely upon the surface water for their homegrown
exercises with not much pipe-borne water around the
communities which is situated in a further place for
the residents to get to. This fact, therefore, propelled
the necessity of this study to nd out the quality
of surface water from the Ogbajarajara river in the
Nwangele local government area. It is therefore
accepted that in the consumption of surface water,
certain tests should have been completed before
consumption in guidelines with the standards of
the World Health Organization (WHO) and Federal
Ministry of Environment (FMEv). [5], evaluated
the water quality of the Nwangele River located in
the Southeast area of Nigeria and concluded that
the river is slightly polluted with heavy metals and
the present river studied has a ow with Nwangele
River. [6], researched the effectiveness of the water
quality index in Izombe in the Imo state of Nigeria.
The scientic research was done in areas where gas
aming is unremitting to build up pollution levels
in rainwater and boreholes as they are viewed as
the two signicant establishments of water supply
in the area. The grouping of pollution among
the examined water assets was accomplished by
contrasting the result of physicochemical tracers
and that of WHO norms for drinking water.
The Ogbajarajara is a well-known river in the
Nwangele local government area of the Imo State
Nigeria. The major occupation in this area includes
farming with few traders. The farming activities
have an important bearing on the ecology of the
area. Daily activities in this river include; washing
and fermentation of cassava. Other activities are
washing clothes, motorcycles, and cars, kitchen
utensils, bathing, shing, and road construction
near the rivers. Recently many technologies such
as the spectrophotometer [7], atomic absorption
spectrometry [8], HPLC [9], gas chromatography
[10], and electrochemistry were used for the
determining of pollutions. The sole aim of this work
is the determination of pollution in surface waters
and the evaluation of human risk assessment due
to the presence of heavy metals in surface water
sources in this area.
2. Experimental
2.1. Study Area
The research area is the Ogbajarajara River located
7
Determination of pollutions in surface of water samples Stanley Chukwuemeka Ihenetu et al
in the Nwangele local government area of Imo
state. The Nwangele is in the tropical rainforest
region and it has two different seasons which are
the dry and wet seasons. The wet season changes
from April completely through October with top
occurrence in June and September through the dry
season starts in November entirely through March
yearly. Nwangele has its headquarter in Amaigbo
and an area of 63 km2 (24 sq mi) and a populace of
128,472 as of the 2006 census (Fig.1). The geology
of the Nwangele area includes plain soil which is
about 0.05-2.0 mm in size and it is to some degree
permeable, deep, and profoundly leached. Nwangele
Local Government has numerous networks
including Abba community, Isu Community,
Umuozu community, Abajah community, and
Amaigbo community. Topographically, the area
falls between directions of latitude 5.7045779011-
5.7111225452 and longitude of 7.13319502340-
7.4222545475. The occupants of these areas are
dominatingly Igbos and they are Christians with not
very many conservatives and other religions. Their
signicant occupation is farming with not many
traders. The farming exercises have a signicant
bearing on the ecology of the area. Daily exercises
in this river incorporate; washing and aging of
cassava. Different exercises are washing clothes,
bikes, cars, cooking wares, bathing, and shing.
2.2. Sample Collection
Ten surface water samples were collected randomly
within the dry and wet seasons during the research
period. Sampling was carried out for both dry and
wet seasons and specied as Ogw and Ogd, where
Fig. 1. Map of the Nwangele L.G.A. and its environs showing the Ogbajarajara River
8
Ogw will be for wet and Ogd will be for dry season
respectively. The samples were collected using a
clean plastic bottle from the surface waters. Five
[5] samples were collected from the river to make
up a composite sampling technique. The plastic
bottles used for the collection of the surface water
samples were appropriately marked and cleaned
before sample collection by soaking it in 10% HCl
for 48 hours, washed and cleaned with deionized
water, and dried up [11,12].
2.3. Laboratory Analysis
The surface water samples were analyzed for
the following: Electrical conductivity (EC), pH,
Dissolved Oxygen (DO), Total dissolved solids
(TDS), Temperature, and color. Also anions and
cations such as, Calcium (Ca), Sodium (Na),
Potassium (K), Phosphate (PO4
3-), Nitrate (NO3
2-
), Sulphate (SO4
2-), Lead (Pb), Copper (Cu), Iron
(Fe), Nickel (Ni), Manganese (Mn), Zinc (Zn) and
Cadmium (Cd) were determined
2.4. Instrumentation and reagents
The heavy metals concentrations were determined
by a double beam ame atomic absorption
spectrometer (FAAS, GBC 906, Aus.). The Air or
N2O-acetylene (C2H2), the deuterium lampas was
used by FAAS. The Avanta system was used for
calculating data. In addition, the electrothermal
atomic absorption spectrophotometer ET-
AAS, GBC, Aus.) was used for the validation
of heavy metals in surface water samples. The
current and wavelength of the HCL lamp were
adjusted for each element. Chemical modiers
such as Pd(NO3)2 and Mg (NO3)2 were used
for increasing the ashing point. The electrical
conductivity was assessed using the HANNA
HI8733 EC METER in µS cm-1 and the pH was
assessed using JENWAY 3510 pH METER. The
DO centralization of the surface water tests was
set up using a JENWAY 9071 digital oxygen
analyzer. The anion examination was done using
multi-parameter bench photometer HI 82300
by HANNA instruments. TDS were done using
Groline TDS meter by HANNA instruments.
Also, many anions and cations such as calcium,
sodium, potassium, iron, copper, cadmium, nickel,
manganese, zinc, and lead, in the surface water
during the dry and wet seasons were analyzed
using atomic absorption spectrophotometer [13].
All reagents with AAS grade such as; metal solution,
inorganic solutions (HNO3, NaOH) were purchased
from Sigma Aldrich (Germany). Metal standard solution
(M) was diluted from the stock of 1000 mg L-1 solution in
2 % nitric acid for further studies. The standard solutions
were diluted by distilled water (DW) from Millipore
(USA). Reagents utilized all through the research were
of high-quality analytical grade, which was bought from
BDH Chemical Ltd, UK, and Sigma-Aldrich Chemie
GmbH, Germany. Detergents and deionized water were
utilized to wash the dish sets and sample bottles. They
were splashed for the time being with a solution of 10%
HNO3 in a 1% HCl solution, trailed by washing with
deionized water. Additionally, the reagents that were
utilized for the assurance of anion focuses with the
Hanna Hi 83,200 Instrument were gotten from Hanna
Instruments. The instrument (GBC 903) utilized for the
assurance of the groupings of metallic elements in the
samples has high sensitivity—commonly (more than
0.9 absorbances) with an exactness (less than 0.5%
RSD) from ten-second integrations for 5 mg L-1 metal
standard.
2.5. Data Analysis
The data were evaluated for their mean and
standard deviation by SPSS software. The data
obtained was subjected to pollution index models
and contamination. Also, Spear-manʼs correlation
coefcient, degree of contamination, Hierarchical
Cluster Analysis (HCA), water quality index
(WQI) analysis and, health risk assessment was
carried out.
3. Results and Discussion
3.1. Physicochemical parameters of surface
water
The physicochemical analysis of the surface water
collected in the dry and rainy seasons is presented
in Table 1. The obtained results were compared
with WHO permissible limits.
Anal. Methods Environ. Chem. J. 5 (1) (2022) 5-21
9
The temperature of water centers on its proposed
usage. The temperature of surface water,
conferring to the standards used falls within 20-
300C. From this study and displayed in Table 1
above, the temperature of the assessed river was
higher during the dry season and this could be
attributed to the hot weather during the dry season.
It can be seen that the season has an effect on the
temperature of the river body. Nevertheless, the
dry season in the study revealed a minor upsurge
in temperature which possibly will be due to the
current weather condition of the environment
at the location of study. Decline and expansion
in temperature level are some of the prominent
signicant highlights of seasonal variation and
weather change. The slight increase in dissolved
oxygen [DO] and pH during the wet season can be
concentrated in accordance with the affectation by
comparative anthropogenic exercises. Interrelated
outcomes were seen for Nworie river [14]. The EC
can critically affect the taste of water. The EC in
this study falls between 100.68±1.0 - 194.74±1.37
μS cm-1 in the dry and wet seasons. The values
obtained were contained by the WHO standard
for risk-free drinking water. The pH value in this
study for the two seasons varied from 5.57±0.22
to 5.73±0.28 μS cm-1 which shows a little acidity
that was not in agreement with the standard pH
(6.50-8.50) recorded by [11] guidelines for safe
drinking water. The lower pH might be a result
of daily anthropogenic activities on this river on
daily basis by the community inhabitants. In the
current study, TDS for wet and dry seasons goes
from 122.17±1.74 mg L-1 and 63.80±0.86 mg L-1.
This may conceivably be a sign of typical pollution
from the runoff of soils in the study area. Color
Determination of pollutions in surface of water samples Stanley Chukwuemeka Ihenetu et al
Table 1. The mean levels of studied parameters linked with WHO in wet and dry season
Parameters
wet dry
W.H.O
Ogw1Ogw2Ogw3Ogw4Ogw5Mean±Std Ogd1Ogd2Ogd3Ogd4Ogd5Mean±Std
Temp. (OC) 24.32 25.43 25.48 25.71 25.53 25.29±0.55 28.37 27.99 29.01 28.36 28.31 28.40±0.38 20-30
DO (mg-1) 8.87 8.92 8.65 9.02 8.9 8.87±0.13 5.49 5.29 5.36 5.41 5.59 5.42±0.12 10.0
EC 197.55 200.21 199.11 199.36 196.85 194.74±1.37 99.02 100.57 101.61 100.96 101.24 100.68±1.0 2500
pH 5.24 5.57 5.82 5.49 5.74 5.57±0.22 5.33 5.02 5.29 5.79 5.44 5.37±0.28 6.50-8.50
TDS 122.07 123.03 123.34 119.36 123.07 122.17±1.74 64.32 63.47 62.63 63.71 64.91 63.80±0.86 500
Color 11.00 12.00 11.00 13 12 11.8±0.83 12.00 13.00 13.00 14.00 13.00 13±0.00 15
NO3
- (mg L-1) 22.4 21.32 22.94 21.32 21.54 21.9±0.73 21.33 21.41 22.31 20.59 21.32 21.39±0.61 50
PO4
2-(mg L-1) 59.93 60.24 61.32 60.97 61.23 60.74±0.61 59.97 60.39 60.12 59.99 60.89 60.27±0.38 1.0
SO4
2- (mg L-1) 0.57 0.52 0.51 0.58 0.52 0.54±0.03 0.42 0.47 0.44 0.41 0.45 0.43±0.02 250
Ca(mg L-1) 3.67 4.02 4.13 3.99 4.17 4.0±0.19 3..40 3.44 3.60 3.41 3.52 3.49±0.08 75
Na (mg L-1) 7.05 7.63 7.04 7.14 7.11 7.19±0.24 6.20 5.98 6.02 6.07 6.13 6.08±0.08 200
K(mg L-1) 5.88 5.39 5.47 5.71 5.69 5.63±0.19 5.09 5.12 5.42 5.15 5.17 5.19±0.13 20
Fe (mg L-1) 8.42 8.36 8.52 8.39 8.42 8.42±0.06 6.31 6.32 6.42 6.11 6.28 6.28±0.11 0.3
Cu(mg L-1) 0.06 0.07 0.07 0.06 0.07 0.07±0.01 0.08 0.09 0.08 0.07 0.09 0.08±0.01 2.00
Cd (mg L-1) 0.00 0.00 0.00 0..00 0.00 0.00±0.00 0.00 0..00 0.00 0.00 0.00 0.0±0.0 0.003
Ni (mg L-1) 0.00 0.00 0.00 0.00 0.00 0.00±0.00 0.00 0.00 0.00 0.00 0.00 0.0±0.0 0.02
Mn(mg L-1) 0.05 0.06 0.05 0.07 0.07 0.06±0.01 0.07 0.08 0.07 0.08 0.08 0.07±0.01 0.4
Zn(mg L-1) 2.22 2.16 2.39 2.35 2.33 2.29±0.09 1.11 1.31 1.09 1.13 1.13 1.15±0.09 3.00
Pb ( mg L-1) 0.63 0.71 0.59 0.82 0.74 0.69±0.09 0.47 0.09 0.50 0.49 0.48 0.40±0.18 0.01
10 Anal. Methods Environ. Chem. J. 5 (1) (2022) 5-21
in essence corresponds to the appearance, taste,
and also general drinkability of water. The color
of the water samples at all the sampling locations
was lower than the permissible limit which has
13.00±0.00 – 11.0.38 PCU in the wet and dry
season against 15 PCU used as the W.H.O standard.
The nitrate in this present study for the wet season
was all found to be below the standard of WHO
standard for safe drinking water both for wet and
dry seasons and they range from 8.72-2154 mg L-1
to 1.20-21.32 mg L-1. Sulfate values observed in the
current study 0.54±0.03 mg L-1 in the wet season and
0.43±0.02 mg L-1 in the dry season were all below
WHO standard for good drinking water and for
domestic water use. Similar ndings were observed
in sulfate values obtained from the study carried
out in the Okumpi river [11]. One of the huge and
crucial nutrients responsible for the richness and
strength of sh ponds is phosphorous. Phosphate
at a sensible sum is tting for the development of
plankton [16]. The phosphate level in both wet and
dry seasons goes from 60.74±0.61 to 60.27±0.38
mg L-1 in both seasons. The high phosphate levels
obtained from this current study; likely could be as
a result of the existence of blue-green growth on
the water surface in the study area in both seasons.
This research perhaps will conclude that phosphate
grounded fertilizer may possibly have been applied
on farmlands near the rivers. Nitrate in all the points
is below the WHO standards. Calcium, potassium,
and sodium as found from the current study in the
wet and dry seasons are below the standard used
for this current study. This result is in agreement
with the outcome of the result obtained from the
Obiaraedu River [17] and the Okumpi River in
Imo State [11].
Fig. 2. Clustered column plots for the distribution of the heavy metal
11
Determination of pollutions in surface of water samples Stanley Chukwuemeka Ihenetu et al
Cadmium and nickel were not detected in the
surface water from the Ogbajarajara River in both
seasons, the plotted distribution of heavy metals
are presented in Figures 2. Iron values observed
in this current study ranges from 8.42±0.06 to
6.28±0.11 mg L-1 in wet and dry season are higher
than WHO standards of 0.3 mg L-1. Iron detected in
every one of the samples in the wet season may be
as a result of the utilization of iron coagulants [18].
This higher concentration of Fe observed during
the wet than the dry season might be because most
mineral residues on the soil may have a high level
of iron, subsequently runoff from residue may taint
the water, particularly during the rainy season.
Copper is an imperative supplement, also drinking
water impurity [19]. Cu amount for both wet and
dry seasons in this current study was all underneath
WHO standard for drinking water and domestic
uses and they went from 0.08±0.01 to 0.07±0.01
mg L-1. Running river is probably going to display
a low level of copper [19]. The low level of copper
in this current study is in line with the result
observed in the Nwangele River [5] and in River
Nworie [14]. Equivalent discoveries were likewise
seen in a study done on River Uramurukwa in Imo
State [20] and Obiaredu River [17]. Manganese
goes from 0.07±0.01 to 0.06±0.01 mg/L through
the wet and dry season. With respect to WHO
standard and NSDWQ for household and drinking
water value for Mn, all points for the wet season
showed a low level of Mn. At high concentrations,
Mn can comprise an aggravation with a particular
metallic taste and staining properties [16]. Zinc
observed both in wet and dry season between
2.29±0.09‒1.15±0.09 mg L-1; were observed to be
below the WHO standard for water quality against
the scheduled level of 3.0 mg L-1. Zinc uncovered
an unwanted harsh taste to water [15]. Pollution
of lead in a river may conceivably be an outcome
of the disbanding of lead from the soil and earth’s
external layer. Lead is in participation a harmful and
superuous metal that has no healthful signicance
to living creatures. Lead levels in every one of
the samples are observed to be high, going from
0.69±0.09 to 0.40±0.18 mg L-1 in the wet and dry
season which are higher than the WHO standard at
0.01 mg L-1. No amount of Pb is viewed as protected
in drinking water. A related study was observed in
a study of the river Uramurukwa in Imo State [20].
3.2. Correlation coefcient matrix
A substantial positive correlation (r > 0.5) was
observed between some of the metals, and anions
parameters. Table 2 shows the coefcient of
relationship for all the metals and anions. The
metals showed a negative association/relationship
with copper and cadmium. Nevertheless,
signicant positive relations during the wet season
were exhibited between NO3
-/Fe (0. 0.888), PO4
2-/
Ca (0.847), PO4
2-/Fe (0.544), PO4
2-/Zn (0.894), Ca/
Cu (0.769) and Mn/Pb (0.934). Signicant positive
associations through the dry season were exhibited
between NO3
-/Fe (0. 888), PO4
2-/Ca (0.847), PO4
2-/
Fe (0.544), PO4
2-/Zn (0.894), SO4
2-/K (0.746), Ca/
Cu (0.769), Ca/Zn (0.524), Fe/Zn (0.691) and Mn/
Pb (0.934). Once the correlation is seen positive,
the establishment of tainting of the positively
connected metals is indistinguishable while
negative correlation suggests disparate/various
bases of contamination. Notable pollution can be
through the washing of engine cars, tricycles and,
motorcycles at the river. Some of the relationship
shown by the metals has been examined by [21].
3.3. Hierarchical Cluster Analysis (HCA)
Additionally, we performed Hierarchical Cluster
Analysis (HCA) to identify groupings of
physicochemical characteristics based on their
Square Euclidian Distance (SED) [21]. The cluster
plots for physicochemical parameters in the water in
dry and wet seasons are presented in Figure 3. In the
dry season, three groups were identied. In group 1,
the combination included all parameters except for
pH, Phosphate, and, EC in another group and then
TDS in the third group. Similarly, in the wet season,
the combination includes all parameters except for
DO and temperature in group 2 while TDS and EC
in group 3. The clustering of all metals in similar
indicates that their source(s) are common. The HCA
results agree with correlation analysis.
12 Anal. Methods Environ. Chem. J. 5 (1) (2022) 5-21
Table 2. Correlation coefcient matrix heavy metals and anions from surface water samples in wet/dry season (mg L-1)
NO3
- PO4
2- SO4
2- Ca Na K Fe Cu Cd Ni Mn Zn Pb
Wet
NO3
- 1
PO4
2- 0.098 1
SO4
2- -0.217 -0.402 1
Ca -0.168 0.847 -0.702 1
Na -0.586 -0.398 -0.277 0.115 1
K 0.051 -0.260 0.746 -0.635 -0.642 1
Fe 0.888 0.544 -0.384 0.256 -0.671 -0.083 1
Cu 0.054 0.424 -0.986 0.769 0.365 -0.772 0.257 1
Cd 000000001
Ni 0 0 0 0 0 0 0 0 0 1
Mn -0.848 0.383 0.154 0.457 0.161 0.063 -0.540 -9.312 0 0 1
Zn 0.338 0.894 -0.072 0.524 -0.721 0.064 0.691 0.047 0 0 0.181 1
Pb -0.900 0.155 0.424 0.203 0.235 0.134 -0.693 -0.271 0 0 0.934 0.040 1
Dry
NO3- 1
PO4
2- 0.098 1
SO4
2- -0.217 -0.402 1
Ca -0.168 0.847 -0.705 1
Na -0.586 -0.398 -0.277 0.115 1
K 0.051 -0.260 0.746 -0.635 -0.642 1
Fe 0.888 0.544 -0.384 0.256 -0.671 -0.083 1
Cu 0.054 0.424 -0.986 0.769 0.365 -0.772 0.257 1
Cd 000000001
Ni 0 000000001
Mn -0.844 0.383 0.154 0.457 0.161 0.063 -0.540 -9.344 0 0 1
Zn 0.338 0.894 -0.072 0.524 -0.721 0.064 0.691 0.047 0 0 0.181 1
Pb -0.900 0.155 0.424 0.203 0.239 0.134 -0.693 -0.271 0 0 0.934 0.040 1
13
Determination of pollutions in surface of water samples Stanley Chukwuemeka Ihenetu et al
3.4. Chemometric Analysis
3.4.1.Contamination factor
The contamination factor was employed to check
the rate of individual metal contamination in
the water samples. Contamination factors were
calculated with equation I.
(Eq. I)
Where Cf connote contamination factor, C metal
address the grouping of heavy metal and C background
means the foundation worth of metal. WHO
suggestions for safe drinking water are taken
as the foundation esteems for a water sample.
Contamination factor ranking followed by Table 3.
3.4.2.Pollution load index (PLI)
The proposed pollution load record through
Tomlinson for distinguishing pollution levels in
soil was applied to the water tests to recognize the
convergence of contamination of heavy metal in the
different areas. The PLI appraises the metal xation
status and gives a thought of the different moves that
can be made to control the issue [22]. Scientists have
assessed the pollution load index utilizing equation II.
(Eq. II)
A PLI value > 1 point toward an instantaneous
intervention to ameliorate pollution; a PLI value <
1 species that extreme rectication procedures are
not needed.
High contamination factor was recorded for lead
Fig. 3. Hierarchical cluster analysis for physicochemical properties in the dry and wet season
Table 3. Contamination factor ranking
Cf values Contamination factor level
Cf < 1 Low contamination
1 ≤ Cf < 3 Moderate contamination
3 ≤ Cf < 6 Considerable contamination
6 ≤ CfVery high contamination
14 Anal. Methods Environ. Chem. J. 5 (1) (2022) 5-21
Fig. 4. Contamination factor and PLI for heavy metals and anions in the wet season
15
Determination of pollutions in surface of water samples Stanley Chukwuemeka Ihenetu et al
and iron in this present study both in wet and dry
seasons. The contamination was higher during
the wet seasons and this may be due to runoff
during the wet season which comes directly
from the farmlands surrounding the river. The
contamination factor was recorded accordingly
Pb>Fe>n>Mn>Cu>Cd and Ni in both wet and dry
seasons. The river has shown a high pollution load
index of 1.192 in wet and 1.8 in the dry season
as shown in Figure 4 above. However, there is a
need to constantly evaluate the water source in this
location.
3.4.3.Water quality index (WQI)
WQI is a number-arithmetic articulation used to
change the enormous number of adjustable data into
a solitary number, which implies the water quality
level. The WQI is created from the accompanying
formula presented to equation III [23].
(Eq. III)
Where: Wi is equal to the comparative weight, wi is
equal to the mass of every single parameter and n is
confer to the parameters. Water quality evaluation
may be developed conferring to equation VI [24, 25].
(Eq. IV)
Where qi is the quality positioning, Ci is the
concentration of every chemical boundary in each
and every water sample in mg L-1, and Si is the
WHO drinking water quality standard. To work
out the WQI, the SI was set up for every chemical
boundary, which is then used to decide the WQI
utilizing Equation V and VI.
(Eq. V)
(Eq.VI)
SIi is the sub-index of ith (mathematics Occurring
at position [i] in the sequence) parameter, qi is
the rating dependent on the concentration of ith
parameter and n is the number of parameters.
The benchmark esteems were procured from
World Health Organization (WHO) standard for
drinking water, 2007. The accompanying point of
arrangement of (WQI) and the nature of water WQI
showed in Table 4 [27].
The examined samples from this study are severely
polluted with physicochemical tracers given the
value of 549 for wet and 328 for a dry season as
reported in Figure 5 below, which makes the water
unsuitable for drinking. Various activities around the
sampling point might have contaminated the rivers
in an intense way, while the wet season recorded
more concentration from this present study.
Table 4. Water Quality Index Values
Cf Value Water Quality
WQI < 50 Excellent water quality
50 < WQI ≤ 100 Good water quality
100 < WQI ≤ 200 Poor water quality
200 < WQI ≤ 300 Very poor water quality
WQI > 300 Unsuitable for drinking
16 Anal. Methods Environ. Chem. J. 5 (1) (2022) 5-21
Fig. 5. WQI values of the sampling points in the wet
season
3.5. Assessment of health risk after
determination
3.5.1.Dermal and ingestion exposure, Hazard
quotient (HQ), Hazard Indices (HI)
Health risk through human exposure to these metals
contamination can be either by means of dermal
ingestion, inhalation, or absorption, which are the
normal contact passageways to the water. Thusly
all the rivers studied in this research are constantly
utilized by individuals generally for their domestic
exercises and sporting exercises. The calculation
of health risk was calculated using equations VII
and VIII according to the USEPA risk estimation
method [30-32].
(Eq. VII)
(Eq. VIII)
Exp ing denotes the exposure dose through ingestion
of water (mg kg-1 per day); Expderm addresses the
exposure dose by means of dermal absorption
(mg kg-1 per day); Cwater: show the normal level
of the assessed metals in water (μg L-1); IR shows
the ingestion level in this study (2.2 L per day for
adults; 1.8 L per day for children); EF shows the
exposure equation frequency (365 days/year); ED
shows the exposure duration (70 years for adults;
and 6 years for children); BW show the normal
body weight (70 kg for adults; 15 kg for children);
AT shows the averaging time (365 days/year × 70
years for a grown-up; 365 days per year × 6 years
for a children); SA shows the uncovered skin area
(18,000 cm2 for adults; 6600 cm2 for children);
Kp shows the dermal permeability coefcient in
water, (cm/h), 0.001 for Cu, Mn, Fe and Cd, though
0.0006 for Zn; 0.0001 for Ni; and 0.004 for Pb; ET
shows the exposure time (0.58 h per day for adults;
1 h per day for children) and CF shows the unit
conversion factor (0.001 L cm-3) [29]. Potential
non-cancer-causing chances in line for exposure
of heavy metals were set up by assessing the
determined toxin exposures from every exposure
path (ingestion and dermal) with the proposal dose
[29] utilizing equation IX.
(Eq. IX)
Where RfDing/derm addresses the ingestion and
dermal toxicity suggestion dose (mg kg-1 day-1).
The RfDderm and RfDing esteem were gotten from the
literature [30, 31]. An HQ under 1 is presumed to
be safe and taken as substantial non-carcinogenic
as equation X [29].
(Eq. X)
Where HI ing/derm is hazard index through dermal
contact or ingestion.
The dermal and ingestion exposure determined
in Table 5 were utilized to decide the hazard
quotient in Table 6. The hazard quotient (HQ)
was resolved and both HQderm and HQing in the
two seasons for all the trace metals checked in
the examination were lower one (1) as seen in
Table 6 for adults and children. This shows there
is basically no adversative health sway expected
to be ordered by any of these metals when the
17
Determination of pollutions in surface of water samples Stanley Chukwuemeka Ihenetu et al
surface water is used. The HQ ing and HQ derm
decreased in the request for lead > iron > zinc
> manganese > copper > nickel > and cadmium,
lead > manganese> iron > copper > zinc > nickel
and cadmium, for the two children and adults
in wet season, individually. HQing and HQderm
decreased in the request for nickel > lead > man-
ganese > copper > zinc > iron and lead >zinc >
nickel > copper > manganese > iron > for the both
children and adults in dry season, individually. It
has been suggested that the calculated HQ results
for metals > 1 for children ought not to be ignored
[32], presumably in light of the fact that, children
are limitlessly disposed to pollutants [33]. The
signicant source of non-cancer-causing health
risk in the two ways were Pb and Ni. The assessed
absolute HQ esteems were less than one as found
in Table 6.
Table 5. Dermal and ingestion exposure (mg kg-1 per day) for adults and children both in wet and dry season
Wet Dry
Metals RfDderm RfDing
EXPderm
(Adult)
EXPderm
(Children)
Ding
(Adult)
Ding
(Children)
EXPderm
(Adult)
EXPderm
(Children)
Ding
(Adult)
Ding
(Children)
Fe 140 700 1.25E-2 3.7E-3 2.26E0 `1.01E0 9.36E-3 2.76E-3 1.97E0 7.53E-1
Cu 8 40 1.04E-4 3.08E-5 2.2E-2 8.0E-3 1.19E-4 3.52E-5 2.5E-2 9.0E-3
Cd 0.5 0.025 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Ni 5.4 20 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Mn 0.96 24 8.94E-5 2.64E-5 1.8E-2 7.0E-3 1.04E-4 3.08E-5 2.22E-2 8.0E-3
Zn 120 300 2.04E-3 6.04E-4 7.19E-1 2.74E-1 1.02E-3 3.03E-4 3.61E-1 1.38E-1
Pb 0.42 1.4 4.11E-3 1.21E-3 2.16E-1 8.2E-2 2.38E-3 7.04E-4 1.25E-1 4.8E-2
Table 6. Hazard quotient for potential non-carcinogenic risk (HQ) and cumulative hazard indices (HI)
for each heavy metal present in wet and dry season for Adult and Children
Wet Dry
Metals HQderm
(Adult)
HQderm
(children)
HQing
(Adult)
HQing
(children)
HQderm
(Adult)
HQderm
(children)
HQing
(Adult)
HQing
(children)
Fe 1.78E-4 2.64E-5 3.22E-3 1.44E-3 6.68E-5 1.79E-5 2.71E-3 1.07E-3
Cu 1.3E-5 3.85E-6 5.5E-4 2.0E-4 1.48E-5 4.4E-6 6.25E-4 2.25E-4
Cd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Ni 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Mn 1.02E-4 275E-5 7.5E-4 2.91E-4 1.08E-4 3.2E-5 9.25E-4 3.33E-4
Zn 1.7E-5 5.03E-6 2.39E-3 9.0E-4 8.5E-6 2.52E-6 1.2E-3 4.6E-4
Pb 9.78E-3 2.88E-3 1.52E-1 5.85E-2 5.66E-3 1.67E-3 8.92E-2 3.42E-2
HI 1.01E-2 2.94E3 1.61E-1 6.13E-2 5.85E-3 1.73E-3 9.46E-2 3.63EE-2
18 Anal. Methods Environ. Chem. J. 5 (1) (2022) 5-21
3.5.2.Chronic daily intake (CDI) and
Carcinogenic risk (CR)
The carcinogenic risk (CRing) shows a gradual
possibility that an individual will foster cancer
during his lifetime inferable from disclosure
under portrayed conditions were registered for
the selected metals in this current study [30]. The
chronic daily consumption of heavy metals through
ingestion was computed using equation XI.
(Eq. XI)
Where C water addresses the centralization of trace
metal in water in (mg L-1), DI infer the; normal
everyday admission of water which is referred to
as daily intake (2.2 L each day for adults; 1.8 L
each day for children) and BW shows the entire
body weight (70 kg for adults; 15 kg for children),
correspondingly [34]. The cancer risk (CR) was
calculated using the formula in equation XII.
(Eq. XII)
whereas SFing represent the cancer slop factor. The
SFing for Pb is 8.5 mg kg-1 per day [26].
The CDI indices for heavy metals during the
experimental time frame for the two ages were
discovered to be in the request for Fe > Pb > Zn
> Cu > Mn > Ni > Cd in wet season; and Fe > Zn
> Pb > Mn > Cu > Ni > Cd in dry season as seen
in Table 7. This proposes that the surface water
expects less health dangers to the two adults and
children by means of the pathways, except for Fe
during the wet season for children which appears to
be more than one. Table 8 present the carcinogenic
risk of Pb for this present study for both adults and
children in wet and dry season, for the reason that
the value of carcinogenic slope factor for different
metals couldn’t be followed in literature, only
lead was determined. Under extreme regulatory
program the carcinogenic risk esteems within the
range of 10−6 and 10−4 could present possible risk
to an individual, subsequently, the outcomes in this
present study showed that the level of Pb in the
surface water could present a carcinogenic risk to
both adults and children.
Table 7. Chronic risk assessment (CDI ing) of heavy metals in adults and children
wet dry
Metals CDI (Adult) CDI
(children) CDI (Adult) CDI
(children)
Fe 2.64E-1 1.01E-0 1.97E-1 7.53E-1
Cu 2.19E-3 8.4E-2 2.51E-3 9.6E-3
Cd 0.00 0.00 0.00 0.00
Ni 0.00 0.00 0.00 0.00
Mn 1.88E-3 5.0E-1 219E-3 8.E-3
Zn 7.19E-2 2.74E-1 3.6E-1 1.38E-1
Pb 2.16E-2 8.28E2 1.25E-2 4.8E-2
Table 8. Carcinogenic risk assessment (CRing) of Pb for wet and dry season for both adults and children
Metal Wet Dry
Adult Children Adult Children
Pb 2.54E-3 9.74E-3 1.47E-3 5.64E-3
19
Determination of pollutions in surface of water samples Stanley Chukwuemeka Ihenetu et al
4. Conclusion
The current study has shown that some actual
appearances of pollution from surface water from
the study area during the wet and dry seasons are not
in line with WHO guidelines. The heavy metals; and
cations were analyzed in surface water by photometer
spectrometry and ame atomic absorption
spectrometry (F-AAS). The results for metal
analysis were validated by electrothermal atomic
absorption spectrometry (ET-AAS). The study has
shown additionally that the pH of all the sampling
points is acidic. Phosphate apparently is high in all
the sampling points at the various season and this can
be related to the high utilization of more phosphate
grounded fertilizer on farmlands surrounding the
Rivers. The current study has uncovered also that the
surface waters are profoundly contaminated with Fe,
Zn and Pb, also this current study has shown that the
surface water isn’t appropriate for drinking purposes
as shown by the high water quality index (> 300).
5. Recommendation
With regard to the results of the present study, the
succeeding references are made after pollution
analysis.
• The water resources observed in the Nwangele
Local Government area should be done routinely
to survey pollution levels (instrumental analysis)
to check the spread of water-related complexities,
particularly in the study area.
• In a circumstance of uncertain water quality,
treatment is recommended through ltration,
boiling, and the utilization of added substances
(alum, liming, chlorine), accordingly lessening the
danger of water-related issues.
6. Acknowledgments
The authors sincerely appreciate the efforts of the
laboratory attendants of the chemistry department
of Imo State University and Anambra state
university Uli.
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