In this study, heavy metals (Cd, Pb, Cr, Zn, Cu and Ni) concentrations were determined in soil samples taken from Pilafu, Shiwa, Fadama-rake and Damdrai along Hong major road using Atomic absorption spectrophotometer. The determined concentrations were used to investigate their influence on human health risk through ingestion, inhalation and dermal exposure path ways. The result revealed that the extent of human health risk varied with exposure path ways, Metal species and sample area. The target hazard quotient for all the elements through each exposure path way were observed to be >1, except Zn in ingestion for adults and in dermal for children and also Cu for children in dermal. However, the health index values for adults were observed to be much higher than the children for THQinh and THQdermal. But for THQing the HI values for children were observed to be higher than the adults. While in inhalation exposure path way all the cancer risk index values were observed to be higher in adults than in children except Ni which is higher in children than in adults. The combine effect for each exposure path way shows high possibility of carcinogenic risk by inhalation route. Indicating some concern about the expansion of unregulated settlements along heavy traffic highways.

1. Risk Assessment of Human Health by Heavy Metals Exposure to Communities along Hong Major Road in Adamawa State, Nigeria
Risk Assessment of Human Health by Heavy Metals Exposure
to Communities along Hong Major Road in Adamawa State,
Nigeria
Nachana’a Timothy
Department of Chemistry, Adamawa State University, Mubi, Adamawa, Nigeria
Email: allen.dusa@gmail.com; Tel.: 08130976890
In this study, heavy metals (Cd, Pb, Cr, Zn, Cu and Ni) concentrations were determined in soil
samples taken from Pilafu, Shiwa, Fadama-rake and Damdrai along Hong major road using Atomic
absorption spectrophotometer. The determined concentrations were used to investigate their
influence on human health risk through ingestion, inhalation and dermal exposure path ways. The
result revealed that the extent of human health risk varied with exposure path ways, Metal species
and sample area. The target hazard quotient for all the elements through each exposure path way
were observed to be >1, except Zn in ingestion for adults and in dermal for children and also Cu
for children in dermal. However, the health index values for adults were observed to be much
higher than the children for THQinh and THQdermal. But for THQing the HI values for children
were observed to be higher than the adults. While in inhalation exposure path way all the cancer
risk index values were observed to be higher in adults than in children except Ni which is higher
in children than in adults. The combine effect for each exposure path way shows high possibility
of carcinogenic risk by inhalation route. Indicating some concern about the expansion of
unregulated settlements along heavy traffic highways.
Key words: Path way, Ingestion, Inhalation, Dermal, Non–carcinogenic, Cancer, Soil, metals.
.
INTRODUCTION
Environmental pollution by heavy metals has become a
global issue in the recent years as it affects public health.
Especially with the continue increase in anthropogenic
activities such as industries and urbanization which
releases pollutants in to the environment.
Soils polluted with heavy metals have become common
across the globe due to increase in geologic and
anthropogenic activities. These activities increased the
concentration of these elements to amount that are
harmful to both plants and animals (Chibuike and Obiora,
2014).
Traffic activities and industrialization are among the major
sources leading to heavy metal contamination in town
roadside soils due to their long-term accumulation (Fan et
al., 2012) Emission of heavy metals from traffic activities is
an important pollution source to roadside farmland
ecosystems. Pollution in developing nations is correlated
with the degree of industrialization, road traffic density and
emission (Filazi et al., 2003; Mlitan et al., 2013).
In addition to the greenhouse gas (GHG), vehicular
emissions were reported to contain cadmium, zinc, nickel,
soot’s and other particulate matters (Susuki and Ono,
2008; Atayese et al., 2009; Dehghani et al., 2018)
contributing to heavy metal overload in the nearby
roadside soils [Fan et al., 2012]. Cadmium for example is
mainly generated from burning of lubricating oil and from
wearing of tires. Similarly, wearing of tires in addition to the
galvanized components of vehicles are additional sources
contributing to Zn build up in the environment. Copper and
lead are by-product of brake wearing, exhaust gas and
worn-out metal alloys in the engine.
Soils and plants in nearby zone of roadside and industrial
areas display increased concentration of heavy metals,
serving in many cases as sinks of pollution loads (Addo et
Research Article
Vol. 4(2), pp. 095-101, December, 2019. © www.premierpublishers.org. ISSN: 1822-424X
International Journal of Toxicology and Environmental Health

2. Risk Assessment of Human Health by Heavy Metals Exposure to Communities along Hong Major Road in Adamawa State, Nigeria
Timothy N. 096
al., 2012; Williams et al., 2018; Mohammadi et al ., 2018).
Soils along roadside and around industries take up large
quantities of pollutants that exceeding the natural emission
levels (Timothy, 2019).
Recently, roadside soils have been an increasingly
important medium for assessing anthropogenic metal
concentrations. Heavy traffic from vehicular activities often
used as indicator of the level of roadside soil pollution by
vehicle derived heavy metals (Saleh et al., 2018;
Bwatanglang et al., 2019).
The environmental issues related to heavy metals
contamination are becoming serious in developing
countries. With the rapid industrialization and urbanization
trend, the increment of traffic activities substantially
contributes to the accumulations of heavy metals
discharged by vehicles in roadside environments. Heavy
metals pollution in agricultural areas owing to traffic
emissions may contaminate the crops growing near the
roadsides (Zeng 2008; Chen et al., 2010; Seifi et al., 2019).
In agricultural areas, uptake of heavy metals through the
soil-crop system could play a predominant role in human
exposure to heavy metals (Timothy, 2019). Heavy metals
present in the roadside soils may be transported through
the food chain, which may have a significant toxicity to both
plants and animals. Therefore farmers are advised not to
farm near the roadside in order to avoid heavy metal
transfer in both animal and human body through the food
chain. This study used heavy metal enrichment in roadside
soils as an indicator to the pollution levels generated by
vehicular activities with some attempt toward establishing
the ecological associated risk.
The aim of the study is to investigate the influence of heavy
metals (Cr, Ni, Cd, Pb, Zn and Cu) concentration in soil
along major road in Hong Adamawa State Nigeria on
human health risk through different exposure path ways.
The outcome of the study could serve as a guide in policy
making toward regulating the expansion of settlements
along roadside area.
MATERIALS AND METHODS
Study Area
Hong is situated in the North eastern part of Nigeria. It is
one of the 21 Local Government areas in Adamawa State.
Hong lies between coordinates 10° 13’54’’N12° 55’49’’E /
10.23°N 12.93° E. The study area has a land area of about
480.65sq.km with population of about 169,183 people
(National Population Census 2006).
Figure 1: Map of Hong showing the sample points
Sample Collection
For the study, twenty four (24) soil samples were randomly
collected from four different locations along the major road
in Hong. Six surface soil samples were randomly collected
from each location. The respective sample points are
Pliafu, Shiwa, Fadama-reke and Damdrai (Figure 1). Soil
samples were pretreated and processed according to the
method described by Timothy (2019). The elemental
concentrations ( Cd, Pb, Zn, Cr, Ni and Cu) of the digested
soil samples were carried out using Atomic Absorption
Spectrophotometer (AAS) 210 VPG Buck Scientific Model.
Health Risk Characterization
The risk assessment processes were carried out to predict
the possible carcinogenic and noncarcinogenic risks that
may prompt up following the exposure of the heavy metals
in the soil to both the adults and children residing along the
major road in the study area. This was achieved by
integrating possible exposure path ways to quantitatively
estimate the likelihood of health hazard. The risk exposure
path ways involve taking the average daily intake (ADI) of
the toxic metals (mg/kg day) following either oral ingestion,
dermal contact, or inhalation route respectively using the
methods described in equations 1-3 (Bwatanglang et al.,
2019; Mehdi et al., 2019; Dehghania et al., 2019;
Kamarehie et al.,2019).
Sa m p le p o int

3. Risk Assessment of Human Health by Heavy Metals Exposure to Communities along Hong Major Road in Adamawa State, Nigeria
Int. J. Toxicol. Environ. Health 097
ADI 𝑖𝑛𝑔 =
10−6× C𝑠𝑜𝑖𝑙× (𝑖𝑛𝑔R × 𝐸𝐹 × 𝐸𝐷)
(𝐵𝑊 × 𝐴𝑇)
(1)
𝐴𝐷𝐼𝑖𝑛ℎ =
𝐶𝑠𝑜𝑖𝑙× (𝑖𝑛ℎ𝑅 × 𝐸𝐹 × 𝐸𝐷)
(𝑃𝐸𝐹 × 𝐵𝑊 × 𝐴𝑇)
(2)
𝐴𝐷𝐼𝑑𝑒𝑟𝑚𝑎𝑙 =
10−6× 𝐶𝑠𝑜𝑖𝑙× (𝑆𝐴 × 𝐴𝐹 × 𝐴𝐵𝑆 × 𝐸𝐹 × 𝐸𝐷)
(𝐵𝑊 × 𝐴𝑇)
(3)
The ADIing, ADIinh, and ADIdermal stands for average
daily intake (ADI) for ingestion, inhalation and dermal
exposure path ways respectively, While Csoil is the
concentration of metal in the soil samples. Other
parameters and their corresponding functions are
described in Table 1 (Sun and Chen 2018; Timothy, 2019).
Target Hazard Quotient (THQ) was used to analyze the
potential non-carcinogenic effect of the metals in the soil
samples by relating the estimated ADI of each elements
with their reference dose (RfD) for each exposure path way
as described in equation 4 (Sun and Chen 2018; Qasemi
et al., 2019). The health index (HI), expressed as the sum
of the THQ as described in equation 5 is used in the study
to describe the cummulative non-carcinogenic effect
(DEA, 2010; USEP 1999). The RfD for each metal and for
each exposure path way are presented in Table 2.
Table 1. Exposure factors used for the health risk assessment through different exposure Path ways for soil
Factor Unit Children Adults
Body weight (BW) kg 15 60
Exposure frequency (EF) days/year 350 350
Exposure duration (ED) years 6 30
Ingestion rate (ingR) mg/day 200 100
Inhalation rate (inhRair) m3/day 10 20
Skin surface area (SA) m2 2100 5800
Soil adherence factor (AF) mg/cm2 0.2 0.7
Dermal Absorption factor (ABS) - 0.1 0.1
Particulate emission factor (PEF) m3/k 1.3 x 109 1.3 x 109
Conversion factor (CF) kg/mg 10-6 10-6
Average time (AT) days
For carcinogen 365 x 70 365 x 70
For non-carcinogens 365 x ED 365 x ED
(Bwatanglang et al., 2019)
Table 2. Reference doses (RfD) in (mg/kg-day) and Cancer Slope Factors (CSF) for the individual heavy metals per
exposure path ways
Elements RfDing RfDdermal RfDinh CSFing CSFdermal CSFinh
Cd 5.60E-04 5.00E-04 5.7E-05 3.80E-01 - 6.30E+00
Pb 3.60E-03 5.25E-04 3.52E-03 8.50E-03 - 4.20E-02
Cr 3.00E-03 6.00E-05 3.00E-05 5.00E-01 - 4.10E+01
Cu 3.70E-02 2.40E-02 4.02E-02 - - -
Zn 3.00E-01 7.50E-02 3.00E-01 - - -
Ni 2.00E-02 5.60E-03 - - - 8.40E-01
(Timothy, 2019)
The cancer risk index (CRI) which represents the
probability of developing any type of cancer over a lifetime
is calculated by integrating the ADI with the respective
cancer slope factors (CSF) for each metal. The description
is presented in equation 6 (Sun and Chen 2018; Rezaei et
al., 2019 ).
THQ = ADIi/RfDi (4)
HI=ΣTHQi (5)
CRI= ADIi x CSFi (6)
A THQ or HI < 1 signify no associated risk, meaning the
exposed population is unlikely to experience any adverse
health hazard. A level of concerns however exist, if the
THQ or HI >1 (Sun and Chen 2018). Furthermore, the CRI
is considered negligible if the CRI < 10-6, acceptable or
tolerable if CRI is 10-6<CRI <10-4, and similarly considered
high if the CRI > 10-4. Equation 7, provides a complete
picture of the cancer risk for an individual following the
combination of all the metals over a lifetime for all the
exposure path ways.
TCRI= CRI (ing) + CRI (inh) + CRI (dermal) (7)
Where, CRI (ing), CRI (inh), and CRI (dermal) are risks
contributions through ingestion, inhalation and dermal path
ways respectively (Kumunda et al., 2016).
RESULTS AND DISCUSSION
The mean concentration distribution of the heavy metals in
surface soil samples along Hong major road were
presented in Table 3. While the calculated ADIi values for
each element and for each exposure path way were

4. Risk Assessment of Human Health by Heavy Metals Exposure to Communities along Hong Major Road in Adamawa State, Nigeria
Timothy N. 098
presented in Table 4. Also the non-carcinogenic and
cancer risk posed by the presence of Cd, Pb, Zn, Cr, Ni
and Cu in soil samples along major road (Pliafu, Shiwa,
Fadama-reke and Damdrai) in Hong Adamawa state
through different exposure path ways (ingestion, inhalation
and dermal contact) were presented in Tables 5 and 6
respectively. The comprehensive result of non-
carcinogenic and cancer risk for various heavy metals and
the multiple exposure path ways for each area was
summarized in Tables 7 and 8 respectively.
Table 3: Mean concentration distribution of the heavy metals in surface soil samples along Hong major road (mg/kg)
Heavy Metals Sample location
Pliafu Shiwa Fadama Reke Damdrai Average
Cd 0.06±0.03 0.05±0.02 0.05±0.02 0.03±0.01 0.05
Pb 0.75±0.05 2.85±0.10 0.80±0.06 2.00±0.09 1.6
Zn 0.95±0.02 1.03±0.01 1.41±0.03 1.22±0.01 1.15
Cr 0.13±0.00 0.0 0.0 0.14±0.00 0.07
Ni 0.47±0.02 0.42±0.00 0.34±0.01 0.27±0.02 0.37
Cu 0.19±0.00 0.27±0.03 0.29±0.01 0.15±0.02 0.23
Total 2.55 4.62 2.94 3.81
All values represent mean ± SD (Standard Deviation) of triplicates determinations.
Table 4: Average daily intake (ADI) values in mg/kg/day for adults and children in surface soil samples along Hong major
road
Elements ADIing ADIinh ADIdermal
Adults Children Adults Children Adults Children
Cd 8.75E-03 1.40E-02 1.35E12 5.38E11 3.55E-02 2.90E-03
Pb 2.80E-01 4.48E-01 4.74E13 1.72E13 1.37E-01 9.40E-02
Cr 1.22E-02 1.96E-02 1.88E12 7.54E11 4.97E-02 4.10E-03
Cu 4.02E-02 6.44E-02 6.19E12 2.48E12 1.63E-01 1.35E-02
Zn 2.01E-01 3.22E-01 3.09E13 1.24E13 8.17E-01 6.76E-02
Ni 6.47E-02 1.04E-01 9.96E12 3.98E13 2.66E-01 2.17E-02
AV. ADI 1.14E-01 1.62E-01 1.63E13 1.22E13 4.11E-01 3.39E-02
Table 5. Target Hazard quotient (THQ) values for heavy metals in adults and children for surface soil samples along Hong
major road for non-carcinogenic risk
Elements THQing THQinh THQdermal
Adults Children Adults Children Adults Children
Cd 15.63 25.00 2.36E15 9.43E14 71.00 5.80
Pb 77.77 124.44 1.34E16 4.88E15 260.95 179.04
Cr 4.07 6.533 6.26E16 1.25E16 828.33 68.33
Cu 1.09 1.74 2.28E14 6.16E13 6.79 0.56
Zn 0.67 1.07 1.03E14 4.13E13 10.89 0.96
Ni 3.24 5.20 - - 47.5 3.87
HI 102.45 163.97 7.86E16 1.84E16 1225.46 258.5
Table 6. Cancer risk index (CRI) values for heavy metals in adults and children for surface soil samples along Hong major
road
Elements CRIing CRIinh CRIdermal
Adults Children Adults Children Adults Children
Cd 0.0033 0.0053 8.50E12 3.38E12 - -
Pb 0.0023 0.0380 1.99E12 7.22E11 - -
Cr 0.0061 0.0098 7.70E12 3.09E12 - -
Cu - - - - - -
Zn - - - - - -
Ni - - 8.36E12 3.34E13 - -
TCRI 0.0117 0.0531 2.65E13 4.05E13 - -
Table 7: Non-carcinogenic hazard indexes (HI) for the six heavy metals and the three exposures path ways for the sample
area
Sample area Pliafu Shiwa Fadama-reke Damdrai
Total Non-Carcinogenic Risk 1.99E14 3.60E14 2.29E14 2.96E14

5. Risk Assessment of Human Health by Heavy Metals Exposure to Communities along Hong Major Road in Adamawa State, Nigeria
Int. J. Toxicol. Environ. Health 099
Table 8: Cancer risks for the Six heavy metals and the three exposure pathways for the sample area
Sample area Pliafu Shiwa Fadama-reke Damdrai
Total Cancer Risk 3.61E14 6.54E14 4.17E14 5.38E14
The mean concentrations of the selected heavy metal
pollutants determined in the roadside surface soil samples
in Hong were presented in Table 3. There was observed
high concentration of Pb, followed by Zn, Ni, Cu, Cd and
Cr in all the four examined areas. This finding agrees with
the findings of Alexander et al. (2018) who state that the
concentrations of Pb and Zn were higher in roadside soils
compared to other heavy metals.
The high concentration of Pb and Zn may be attributed to
metal construction works, tire wear, galvanized parts such
as fuel tanks, brake wear, welding of metals, exhaust gas
and worn metal alloys in the engine as well as mechanical
and dry cell battery workshop (Winther and Slentø, 2010)
which is a common practice alone the major roads in Hong
town. The heavy metals in urban roadside soil take their
origin from sources such as tire wear, vehicle emissions,
repairs, painting, panel beating, battery charging, iron-
bending, and discharges from industries, lubricating oil
and corrosion of vehicle parts (Akbar et al., 2016). Zn, Pb,
Cr, Cd, Cu and Ni come mainly from vehicular activities
such as tire wear, wear of brake linings, discharge from
battery, emission from gasoline vehicles, studded tires,
vulcanizing, smelting, soldering work and engine wear.
Corrosion of radiator, bushing and brake wirers and the
various types of friction materials and deicing chemicals
used on road surfaces for slipperiness control could
release metals such Ni, Cr, and Cu into the environment
(Alexander et al., 2018; Shinggu 2014).
Roadways and automobiles are considered to be one of
the largest sources of heavy metals. Lead, Zinc and
copper are three of the most common heavy metals
released from vehicle emission accounting for most of the
heavy metals in road runoff.
Based on the exposure factors listed in Table 1, the
calculated ADIi values for each element and for each
exposure path way (Table 4) for both the adults and
children were observed to fall in this order
Pb>Zn>Ni>Cu>Cr>Cd. However, these values were
observed to be higher than their RfD values (Table 2).
From the result, the average exposure dose of the three
exposure path ways for both adult and children observed
to increase in the order of ADIdermal<ADIing<ADIinh. The
overall result showed that adults are more susceptible to
higher level of exposure dose compared to the children
except in ingestion in which children were more exposed
(Table 4). This observation may be so because adult are
directly involved in the activities that produces such heavy
metals.
The target hazard quotient (THQ) (Table 5) for all the
elements following each exposure path way were
observed to be >1, except Zn in ingestion for adults and in
dermal for children and also Cu for children in dermal. The
THQing values for both the adults and children were
observed to follow the ranking Pb>Cd>Cr>Ni>Cu>Zn. The
THQinh values for both the adults and children observed
to follow the order Cr>Pb>Cd>Cu>Zn. While the exposure
through the dermal route were observed to follow the
ranking Cr>Pb>Cd>Ni>Zn>Cu for both adults and
children. The THQ < 1 recorded for Zn and Cu further
suggest no associated risk following either the ingestion or
dermal exposure for both the adults and children. However
The THQ>1 recorded for all the elements showed higher
risk associated following the ingestion, inhalation and
dermal exposure for both the adults and children. The non-
carcinogenic risks posed by combining the respective THQ
values for each exposure path way were observed to leads
to human health index (HI) values >1, which means there
is risk possibility associated with all the three exposure
path ways for both the adults and children. However, the
HI values for adults were observed to be much higher than
the children for THQinh and THQdermal suggesting that,
at a relatively high level of exposure, adults will be more
likely at risk than the children. But for THQing the HI values
for children were observed to be higher than the adults
suggesting that, at a relatively high level of exposure,
children will be more likely at risk than the adults this
finding agreed with the report of Bwatanglang et al.,(2019)
which could be linked to the higher intake rates per unit
body weight observed in children (Xiao et al., 2017; Sun
and Chen, 2018) The HI values were observed to fall in
this order HIinh>HIdermal>HIing. The result was observed
to fall in different category with the findings conducted on
the road dust in urban parks of Beinjing (Du et al., 2013)
and the road dust sample in the city of Duzce, Turkey
(Taşpınar and Bozkurt 2018).
The lifetime cancer risk index (CRI) for the adults and
children were presented in Table 6. The
carcinogenic risk was analyzed for Pb, Cd, Cr and Ni for
the ingestion and inhalation exposure path ways only. For
regulatory purposes, a cancer risk in the range of 10-6 to
10-4 are considered acceptable (Sun and Chen 2018).
From the results presented in the table, the CRI for both
ingestion and inhalation exposure path ways were
observed to be higher than the acceptable limit (< 10-4).
The CRIing for both age categories were observed to be
in the order of Cr >Pb >Cd and the CRIinh in the order
Ni>Cr>Cd>Pb. In all, the CRI for ingestion exposure path
ways were observed to be higher in children than the
adults. While in inhalation exposure path way all the CRI
values were observed to be higher in adults than in
children except Ni which is higher in children than in adults.
The combine effect for each exposure path ways show
high possibility of carcinogenic risk by inhalation route.
From the results it will suffice to say that children are more
susceptible to potential carcinogenic risk than the adults

6. Risk Assessment of Human Health by Heavy Metals Exposure to Communities along Hong Major Road in Adamawa State, Nigeria
Timothy N. 100
through ingestion route this could be as a result of their
skin been light as compare to the adult skin. Furthermore,
the inhalation exposure path way was observed to be the
major route compared to the lifetime TCRI by ingestion
exposure route. According to the results, the potential
carcinogenic risk following the ingestion route could come
from Cr exposure. Similarly, exposure to Ni could be the
likely source of carcinogenic risk by inhalation exposure
pathway.
The total non-carcinogenic indices (HI) for various heavy
metals and the multiple exposure path ways for each
sampling area were summarized in Table 7. The risk from
all the sampling area were higher than the thresh value of
1. The heavy metals in soils around all the sampling areas
will cause a problem as a result of high HI value.
Therefore, local residents should not settle near the road
side in order to reduce the effect of the toxicity on human
health.
The comprehensive assessment results of cancer risk in
the soils from different sampling area are shown in Table
8. The wide range of cancer risk was calculated from
3.61E14 - 6.54E14 in Pliafu and shiwa respectively. By the
US environmental protection agency, our results showed
higher risk than an acceptable value of 1E-06 – 1E-04. The
total combined risk (TCR) show the following decreasing
order 6.54E14>5.38E14> 4.17E14>3.61E14 for
Shiwa>Damdrai> Fadama-reke>Pliafu respectively.
CONCLUSION
The influence of heavy metals (Cd, Pb, Cr, Zn, Cu and Ni)
concentration in soils around four different sample points
along major road in Hong on human health risk through
different exposure path ways was investigated. The result
revealed that the extent of human health risk varied with
exposure path way, metal species and sample area. The
calculated ADIi values for each element and for each
exposure path way for both the adults and children were
observed to fall in this order Pb>Zn>Ni>Cu>Cr>Cd. The
target hazard quotient (THQ) for all the elements following
each exposure path way were observed to be >1, except
Zn in ingestion for adults and in dermal for children and
also Cu for children in dermal. However, the HI values for
adults were observed to be much higher than the children
for THQinh and THQdermal suggesting that, at a relatively
high level of exposure, adults will be more likely at risk than
the children. The CRI for both ingestion and inhalation
exposure pathways were observed to be higher than the
acceptable limit (<10-4). Furthermore, the inhalation
exposure path way was observed to be the major route
compared to the lifetime TCRI by ingestion exposure
route. According to the results, the potential carcinogenic
risk following the ingestion route could come from Cr
exposure. Similarly, exposure to Ni could be the likely
source of carcinogenic risk by inhalation exposure path
way. The total non-carcinogenic indices (HI) for various
heavy metals and the multiple exposure path ways for
each sampling area were higher than the thresh value of
1. The heavy metals in soils around all the sampling area
will cause a problem as a result of high HI value. The
comprehensive assessment results of cancer risk in soils
from different sampling area and the multiple exposure
path ways show the following decreasing order
Shiwa>Damdrai> Fadama-reke>Pliafu. Therefore, local
residents should not settle near the road side in order to
reduce the effect of the toxicity of these heavy metals on
human health.
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7. Risk Assessment of Human Health by Heavy Metals Exposure to Communities along Hong Major Road in Adamawa State, Nigeria
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Accepted 4 December 2019
Citation: Timothy N (2019). Risk Assessment of Human
Health by Heavy Metals Exposure to Communities along
Hong Major Road in Adamawa State, Nigeria. International
Journal of Toxicology and Environmental Health, 4(2):
095-101.
Copyright: © 2019 Timothy N. This is an open-access
article distributed under the terms of the Creative
Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium,
provided the original author and source are cited.