Journal of Environmental Protection, 2014, 5, 65-70
Published Online January 2014 (
Selected Tr ace Elements in Domestic Water Boreholes and
Their Implications on Human Health, in Huruma Estate,
Eldoret Municipality, Uasin-Gishu County, Kenya
Taratisio Ndwiga
Department of Environmental Health, School of Public Health, Moi University, Eldoret, Kenya.
Received November 8th, 2013; r evised December 11th, 2013; accepted January 7th, 2014
Copyright © 2014 Taratisio Ndwiga. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. In accor-
dance o f the Creative Commons Attribution License all Copyrights © 2014 ar e reserved for SCI RP and the owner of the intel lectual
property Taratisio Ndwiga. All Copyright © 2014 are guarded by law and by SCIRP as a guardian.
Trace elements constitute less than 1% of t he ro cks i n the crust ( Stumm and Morg an, 19 91 ). In the hu man body ,
they constitute less than 100 mg/kg (0.01%). These elements are released to the environment naturally by wea-
thering and volcanic activities (Flint and skinner, 1997). It has been observed that trace elements are greatly ab-
sorbed and r etained in the body when in liquid diet. Thi s phenomenon also influe nces the risk to hu man healt h,
especially of infants and children whose immature digestive system further promote absorption of toxic heavy
metals. The study was based on the analysis of domestic borehole water supplies in Huruma estate of Eldoret
Municipality for selected trace elements and their implications on human health. The boreholes were systemati-
cally select ed for sampling point s and trace ele ments, Cr, Cu a nd Se analyzed using AAS. Statist ical analy sis for
mean, standard deviation and confidence interval limits was done using SPSS. The statistical t-test was used to
test for significance differences at (p = 0.05). The graphs were drawn using the Microsoft Excel package. The
resulting data obtained from analysis were compared w ith W HO data for dr inking w at er. In t he study , t he mean
values of the following parameters were as follows: Chromium 17.9 µg/L, Copper 563 µg/L and Selenium 22.7
µg/L. There was a significant difference at 5% level of significance (p = 0.000) in all the parameter values among
the sa mpling points in Hur uma estate. The abov e mean values were far below the WHO recommended limits for
drinking water. It was concluded that the borehole water from Huruma was fit for drinking and therefore could
not cause cancer and cardiovascular diseases. However, borehole water should be used if other water sources
(tap water etc.) were not availa ble. All t he industri es ne ar Huru ma estat e should carefully analyze and regularly
monitor their liquid waste ef fluents to ensure that no harmful discharges get into the soil.
Trace Elements; Human Health; Chro ni c Exposure; Borehole; Non-Communicable Disease
1. Introduction
Tr ac e el eme nt s co nst it ut e less than 1 % o f t he r oc ks i n the
crust [1]. In the human body, they constitute less than
100 mg/kg (0.01%). These elements are released to the
enviro n ment nat urall y b y wea ther ing a nd vo lca nic acti vi-
ties [2]. It has been observed that trace elements are
greatly absorbed and retained in the body when in liquid
diet. This phenomenon also influences the risk to huma n
health, especially of infants and children whose imma-
ture digestive system further promote absorption of toxic
heavy metals. Deficiencies, excesses or imbalances in the
supply of trace of elements from water and dietary
sources can be an important influence on animal and
human health and susceptibility to diseases.
The concentration of trace elements in the environ-
ment is modified by a variety of natural processes and
deliberate and accidental human activities. Certain trace
element e.g. Selenium (Se) and Molybdenum (Mo) in-
trigue modern scientists because of the environmental
Selected Trace Element s in Domestic Water Borehol es and Their Implicat ions on Human Health,
in Huruma Estate, Eldoret Municipality, Uasin-Gishu County, Kenya
consequence of their double-edged behavior. Depending
on their concentration and chemical forms, they function
as essential elements or potent toxicants to humans, li-
vestock, plans, waterfowls and certain bacteria. Manga-
nese (Mn), Chromium (Cr), Vanadium (V) and Copper
(Cu) are known to have beneficial effects on heart dis-
ease as illustrated in their high concentrations in the lo w
death-rate areas of Georgia, America [3]. Therefore, the
low-death-rate may be as a result of an abundance of
beneficial trace elements.
In Kenya, non-communicable diseases, especially car-
diovascular diseases and cancer are increasing rapidly.
Hypertension accounts for the majority of the cardiovas-
cular disorders in Kenya and in developing countries.
Regrettably, the ability to deal with this emerging prob-
lem is being hindered by two major factors a paucity
epidemiological data about incidence, prevalence and
trends in disease occurrences and absence of adequate
resource allocation locally and by the international
community [4].
Incidences of cancer and cardiovascular diseases are
on the increase with some forms associated with trace
element concentration. The study conducted at MTRH by
[5] sho ws that e sopha geal cancer is the 9th most co mmo n
cancer in the world, and the 5th most common cancer in
developing countries, with approximately 300,000 newly
diagnosed patients every year. He reported that the can-
cer cases recorded at the Hospital, from Jan. to May 2001
showed that the cancer incidence was 2% per 100,000
per year. Kenyatta National Hospital recorded the overall
country incidence at 67% per 100,000 per year over the
same period.
Domestic water particularly in volcanic environments
is usually associated with high concentration levels of
elements. The concentration ranges for trace elements in
domestic water supplies is usually unknown because rou-
tine analysis ignores this component. Trace elements are
further more toxic than other pollutants when the y occur
outside their recommended ranges and are greatly ab-
sorbed and retained in the body when taken in liquid
form. The above scenario merits an investigation to cha-
racterize the domestic water supplies in terms of selected
trace elements and find out their implication on human
Eldoret Municipality in Rift Valley Province is asso-
ciated with volcanic activities that are a major source of
trace elements. Water is a basic requirement for life and
is extensively used in everyday life. However, if conta-
minated it has a capacity to transmit many disease. Fur-
thermore, water is a major source of trace elements in
human diet yet most reports on water analysis give only
the concentrations of major elements that are recognized
to affect the quality of water for domestic, agricultural
and industrial u ses.
The findings will contribute to knowledge in the qual-
ity of domestic water boreholes in Huruma estate in El-
doret Municipality in terms of the selected trace elements.
Future decision on the necessary water treatment
processes could be based on the findings and therefore
lead to improvement in water quality and hence human
health. The objective was to determine the level of Cr,
Cu and Se in domestic water supplies (boreholes) in Hu-
ruma, Eldoret Municipality and determine the suitability
of water for drinking.
Chronic exposure of chromium in man causes cancer
of the respiratory tract and skin eczema. It also causes
renal tubular necrosis. The lethal oral dose in human
adults is 50 - 70 mg of soluble chromates per kg body
weight. At this level of ingestion, chromium causes poi-
soning of blood-forming organs. Chronic toxicity can be
observed in several other mammalian species, with hex-
avelant chromium in concentrations of more than 5 mg/L
It is possible for aquatic animals to accumulate high
and ultimately lethal concentrations of heavy metals over
long period from extremely low water concentrations. In
USA the brown bullhead (Lctalurs nebulosus) has been
shown to accumulate chromium to concentrations more
than 2600 times that found in the stream water although
this was still lower than the concentration in the stream
sediment. In the IIIionis River the concentration of
chromium in the muscles of omnivorous fish was found
to be appreciably greater than that in the muscles of car-
nivor ous fis h alt hou gh aga in t he c once ntr atio ns were l ess
than that of the river sediment [7].
[8] explains that the average background concentra-
tions of copper in air in rural areas range from 5 to 50
ng/m3. Copper levels in fresh water of 1 - 20 µ/L are
found in uncontaminated areas. The adverse health ef-
fects associated with copper include: anemia and bone
abnormalities (due to copper deficiency), vomiting, di-
arrhea, headache, respiratory difficulty, liver and kidney
failure, massive gastro-intestinal bleeding and death [8].
Selenium occurs naturally in a number of inorganic
forms, including selenide, selenate and selenite. In soils,
selenium most often occurs in soluble forms like selenate
(analogous to sulfate), which are leached into rivers very
easily by runoff. Natural sources of selenium include
certain selenium-rich soils, and selenium that has been
bioconcentrated by certain toxic plants such as locoweed.
Anthropogenic sources of selenium include coal burning
and mining and smelting of sulfide ores [9].
Although selenium is an essential trace element it is
toxic if taken in excess. Exceeding the Tolerable Upper
Selected Trace Elements in Domestic Water Boreholes and Their Implications on Human Health,
in Huruma Estate, Eldoret Municipality, Uasin-Gishu County, Kenya
Intake Level of 400 micrograms per day can lead to se-
lenosis [10]. Symptoms of selenosis include a garlic
odour on the breath, gastrointestinal disorders, and hair
loss, sloughing of nails, fatigue, irritability and neuro-
logical damage. Extreme cases of selenosis can result in
cirrhosis of the liver, pulmonary edema and death [10].
There has been growing interest in trace elements in
the environment because of their toxicity to plants and
other living organisms. Trace metals have effects on hu-
man body organs especially the brain, kidney and the
skin [11-13], analyzed 20 trace elements in samples fro m
60 boreholes located in the upper east and west regions
of Ghana and observed that most trace elements concen-
trations were high as compared to their concentrations
found in natural water. Al, Fe, Mn, Zn, Sr, and Ba were
excessively high in concentration in comparison with
WHO guidelines.
[14] measures concentrations of heavy metals in the
borehole at Dumasi in the Wassa West district of the
Republic of Ghana. The concentrations of the metals in
the ground water from Dumasi borehole show that resi-
dent adults and children who use water from the bore-
holes are at serious risk from exposure to health hazards
associated with exposure to the above metals in the bo-
reholes in Du masi.
[15] explains that selenium deficiency is suspected to
be a factor in the etiology of esophageal cancer in the
Linxian and Cixian regions of the People’s Republic of
China. Vitamin trials in the Linxian area indicate that
combined supplementation with β-carotene, vitamin E
and Se reduces the mortality rate. He further explains
that in order to further evaluate the role of Se, the distri-
bution of total Se in cultivated top-soils, grain, human
hair and drinking water is studied in 15 villages in the
Cixian area, People’s Republic of China which had one
of the highest mortality rates from esophageal cancer in
the world in the 1980-1990s. His study de monstrate s that
total Se concentrations in drinking water, soil, grain and
hair increase from the low esophageal cancer area to the
high cancer area, contrary to the expected trend.
2. Methodology
2.1. Study Area
This study area was chosen due to its high population
density and the fact that it lies where the soils are drained,
shallow, reddish brown and viscous, having developed
from older basic igneous rock, particularly basic tuffs,
basalts and phonolites. These types of soils are volcanic
in nature and may contain trace elements, which is the
subject of this study. The study area (Figure 1) covers
the whole of Huruma estate, in Eldoret Municipality.
Huruma is one of the estates in Eldoret Municipality
with the highest population, while pioneer and Elgon
View have the lo west population [16]. The rapid popula-
tion growth in the estate has led to shortage of housing,
health facilities, water, poor sewage disposal and general
degradation of environmental quality. This has in turn
strained the Eldoret Municipality to provide these ser-
vices [16].
The indust ries found ne ar or aro und thi s esta te inc lude
the Kenya Pipeline and the Rai Plywood. See Figure 2
b el ow.
2.2. Sapling Procedures
The borehole sampling stations were systematically se-
Figure 1. A Map of Eldoret Municipality (in Uasin-Gishu District) showing the study area (Huruma Estate). Source: De-
partment of Geography Moi University.
Selected Trace Element s in Domestic Water Borehol es and Their Implicat ions on Human Health,
in Huruma Estate, Eldoret Municipality, Uasin-Gishu County, Kenya
Figure 2 . Sketch of the study showing sampling stations and industri es.
lected after every two plots. Domestic water sample were
collected in duplicate using 500 ml plastic containers,
pre viousl y soaked overn ight i n a mixt ure o f concent rated
nitric and hydrochloric acids. The bottles were rinsed 3
times in distilled water and the sample respectively, 2
mls of concentrated HCL was added for preservation of
trace metals [17]. When sampling boreholes, the water
sample, was lifted using a water bucket only dedicated
for sampling.
2.3. Laboratory Methods
The duplicate water samples was pre-concentrated by
heating an aliquot of 100 ml form each sample on a water
bath at 85˚C until the volume was reduced to 10 ml. the
concentration was cooled and analyzed for Cu, Se, and
Cr, using an atomic absorption spectrometer (AAS), Va-
rian mode. The AAS was chosen because of its availabil-
ity, high accuracy, and high precision and sufficiently
low detection limits for most trace elements in the envi-
ronment [18].
2.4. Data Analysis and Data Presentation
Statistical analysis was done using SPSS for mean, stan-
dard deviation, t-test and confidence interval limits. The
statistical t-test was used to test for significance differ-
ence at (p = 0.05). T he graphs were dr awn usi ng the Mi-
crosoft Excel package.
3. Results and Discussion
The table (Table 1) be l ow s h o ws the Se, Cr and Cu var i-
ations in the statio ns 1 (station near I ndustries) to 20 ( sta-
tions away from industries and near river Sosiani). The
results indicate that soils on the inhabited areas (the up-
per areas near the factories) of Huruma Estate had
slightly more trace elements than the lower side to the
The mean value of Selenium, Copper and Chromium
are shown in Table 1 and Figure 3 and illustrates the
levels of these co mpounds a t d ifferent sampli ng points in
Huruma estate.
The overall selenium mean value was 22.7 µg/L and
selenium values varied from 35 µg/L, at sampling point 1
to 16 µg/L, at sampling point 13 and values increases
again to 18 µg/L at sampling point 20. There was a sig-
nificant difference (PV = 0.000) at 5% level significance
in copper levels among the sampling points in this area.
At 95% confidence level, the copper concentration was
22.7 ± 2.7 µg/L. These variations could be due to agri-
cultural activitie s from nearby farms and industrie s to the
upper parts of the estate, as most selenium is used prepa-
rations of pharmaceuticals as a nutritional feed additive
for poultry and livestock, and in pesticides formulations
[19]. This research finding concurs with [20] who found
out that selenium concentration values were below [21]
recommendation. However, the water is still fit for hu-
man consumption as the selenium concentrations are far
below the WHO recommended limits of 0.05 mg/L.
The Copper concentration data shows that sampling
point 1 had 307 µg/L, and this rapidly to a high value of
1031 µg/L at sampling point 10 and the values started
reducing again to a low level of 207 µg/L. t he mean le ve l
of copper concentrations along the sampling point was
563 µg/L. there was a significant (PV = 0.000) difference
at 5% level of significance in copper levels along all the
sampling points. At 95% confidence level, the copper
concentration was 562.75 ± 0.7 µg/L. This could be due
to copper ions coming from rusting roofing sheets and
water plumbing pipes from houses in estate. This is the
most populated area in Huruma estate. [20] confirms
these results, where he found out that copper concentra-
tion values were below 2.0 mg/L as recommended by
[21]. Ho wever, the wat er is s afe for drinking since the Cu
levels are below the WHO recommenced limits for
dri nking water (1.3 - 2.0 mg/L).
River Sosiani s
Selected Trace Elements in Domestic Water Boreholes and Their Implications on Human Health,
in Huruma Estate, Eldoret Municipality, Uasin-Gishu County, Kenya
Figure 3. Se, Cu and Cr concentration variation with sam-
pling stations.
Table 1. Variations of Se, Cr and Cu in all the sampling
stations (1 - 20).
Station Se Cr Cu Station Se Cr Cu
1 21 307 35 11 17 984 23
2 19 309 33 12 18 861 21
3 18 250 28 13 17 784 16
4 16 331 27 14 17 684 19
5 18 491 24 15 16 492 18
6 18 577 25 16 17 484 17
7 19 667 27 17 18 392 18
8 18 845 28 18 18 362 17
9 18 971 23 19 17 224 17
10 19 1031 19 20 18 207 18
Chromium values varied from 21 µg/L, at sampling
point 1 to 16 µg/L, at sampling point 15 and 18 µg/L at
sampling point 20. The overall mean was 17.85 µg/L. At
95% confidence, chromium values were 17.9 ± 0.6.
There was a significant difference (PV = 0.000) at 5%
level of sig nifica nce in chr omium le vels a mong t he sam-
pling points and this due to the proximity of these points
to the Raiply wood industry which manufactures paper
products (among other products). However, the water
quality was not affected as the chromium values were
below the WHO recommended levels (0.01 mg/L) fo r t he
drinking water. This compares well with [20], where he
found that chromium values were below WHO recom-
mended levels.
4. Conclusions and Recommendations
4.1. Conclusions
Analysis of data indicated that the quality of water from
borehole water in Huruma estate was acceptable. The
volcanic soil around this area does not have any effect at
all on the borehole water quality as earlier thought. The
cases of cancer and cardiovascular diseases from this
area are due to other causes, but not borehole water.
Variations of copper concentrations around the dense-
ly populated area of Huruma estate are affected by the
human activities. Use of Copper pipes for water plumb-
ing and corroded iron sheets has contributed to high le-
vels of copper concentrations (1031 µg/L) as confirmed
by the high le vel s of cond ucti vity in the ar ea at sampli ng
points 10 (at 474 µg/L). These levels are however, lower
than the recommended WHO limits for drinking water.
Mean selenium levels (22.65 µg/L) and chro miu m levels
(17.9 µg/L) are still very low as compared to WHO lim-
its for drinking water. Therefore, water from Huruma
borehole will not cause cardiovascular and cancer dis-
4.2. Recommendations
The government through the municipal council of Eldo-
ret should give extensive health education on construc-
tion of borehole and use of borehole water to the Huruma
residents. The municipal council should assist the Huru-
ma residents in the construction of pit latrines to minim-
ize borehole water contamination in the future. All the
industrial waste effluents should be regularly analyzed
and carefully monitored to ensure that no harmful dis-
char ges get into t he soil.
The community should make efforts to have clean wa-
ter by boiling water from their boreholes and rehabilitat-
ing their boreholes. They should also make efforts to
ensure that they do not pollute borehole water supplies
by discharging harmful wastes. The borehole water
shou ld o nl y be use d fo r cl ea ni ng a nd was hi ng purp o ses if
other water sources (tap water etc.) are reliable and pure
enough for cooking and drinking.
I wish t o than k the follo wing for their advice a nd enco u-
ragement throughout the research project period. Dr.
Augustine Afullo, Lecturer Kenyatta University, for his
encouragement and advice during the research period.
Mr. P. K. Maritim, Chief Technician and Mr. Rocky
Mndumu Lewela, Senior Technician department of En-
vironmental Biology and Health, School of Environmen-
tal Studies, Moi University for assisting me with trace
ele me nts anal ysis for my water samples.
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