









































Pa
ge

 
1



Pa
ge

 
19

American Journal of   
Environment and Climate (AJEC)

Assessment of  Common Ambient Air Pollutants and Respiratory Health Outcomes 
among Road Construction Workers in Imo State, Nigeria 

John Mark Bwala1, Agwu Nkwa Amadi1, Chimezie Christian Iwuala1, Ugo Uwadiako Enebeli2* 

Volume 4 Issue 3, Year 2025
ISSN: 2832-403X (Online) 

DOI: https://doi.org/10.54536/ajec.v4i3.5615
https://journals.e-palli.com/home/index.php/ajec

Article Information ABSTRACT

Received: July 07, 2025

Accepted: August 11, 2025

Published: September 01, 2025

Road construction workers are more likely to experience respiratory health problems 
because they are frequently exposed to air pollution. The purpose of  this study was to 
assess the common ambient air pollutants and respiratory health outcomes among Nigerian 
road construction workers in Imo State. A cross-sectional study was conducted in Imo 
State, Nigeria, with 353 road construction workers from Imo State’s three senatorial zones 
selected using a multistage sampling technique. Gas meters placed at key points were used 
to measure the ambient concentrations of  carbon monoxide (CO), sulphur dioxide (SO2), 
and suspended particulate matter (SPM) at construction sites. Respiratory symptoms and 
forced vital capacity (FVC) of  the road construction workers were assessed by qualified 
health professionals. The mean CO, SO2, and SPM concentrations in Imo West were 
182.40±6.41ppm, 516.24±55.03μg/m3, and 1956.22±30.75μg/m3 respectively; in Imo East, 
185.34±6.46ppm, 518.26±55.12μg/m3, and 1960.17±30.79μg/m3 respectively; and in Imo 
North, 187.51±6.49ppm, 520.14±55.34μg/m3, and 1956.68±30.25μg/m3 respectively. In all 
zones, CO, SO2, and SPM levels significantly exceeded safe thresholds, according to the one-
way ANOVA analysis (p<0.05) performed with SPSS. Among the most common respiratory 
health problems were coughing, 211 (59.77%); sneezing, 290(82.15%); catarrh, 79(22.38%); 
sore throat, 72(20.39%); asthma, 29(8.22%); short breath, 121(34.28%); pneumonia, 
66(18.70%); headache, 133(37.68%); and wheezing, 170(48.16%). Mean FVC values were 
2263.34±482.33 ml (Imo West), 2578.80±751.80 ml (Imo East), and 2382.78±610.42 ml 
(Imo North). To mitigate respiratory health risks, road construction workers are strongly 
recommended to consistently use personal protective equipment, particularly respiratory 
masks, during work activities. 

Keywords
Ambient Air Pollutants, Imo 
State, Nigeria, Respiratory Health, 
Road Construction Workers

1 Department of  Public Health, Federal University of  Technology Owerri, Nigeria
2 Department of  Community Medicine, Rhema University Nigeria, Aba, Nigeria 
* Corresponding author’s e-mail: doctorenebeli@yahoo.com

INTRODUCTION 
Road construction workers’ respiratory health is seriously 
endangered by the exposure to hazardous pollutants such 
as dust, respirable crystalline silica (RCS), diesel exhaust 
fumes, and other toxic gases that come with road building 
activities (Boadu et al., 2023; Sarabi et al., 2025). Asthma, 
chronic bronchitis, and diminished lung function are 
among the respiratory disorders associated with these 
pollutants, which are produced by activities such as 
excavation, material handling, and heavy machinery 
operations (Kunar & Mandal, 2025; Landwehr et al., 
2023). Road building is a crucial industry in Nigeria, 
especially in Imo State, yet little is known about the risks 
to employees’ occupational health (Bwala et al., 2025). 
Effective interventions and regulations to safeguard these 
workers are hampered by the absence of  thorough data on 
exposure to air pollutants and the health effects of  those 
exposures. By measuring the concentrations of  common 
ambient air pollutants, including SPM, CO, and SO₂, at 
road building sites in Imo State, Nigeria, and analyzing 
their relationship to worker respiratory health effects, 
this study fills this knowledge gap. In order to reduce 
occupational health risks in this population, this study 
measured pollutant exposure, ascertained the frequency 
of  respiratory symptoms, and presented data to support 
the development of  policies and focused interventions.

LITERATURE REVIEW
Road and industrialization construction activities expose 
workers to hazardous compounds that might harm their 
respiratory health, making it a major source of  ambient air 
pollution (Abdullahi et al., 2022; Hasan et al., 2021; Sarabi 
et al., 2025). Road construction workers’ occupational 
health risks are increased by the physically taxing nature 
of  road construction as well as exposure to pollutants 
from materials and processes. Significant air pollutants 
are produced by operations including site clearance, 
earthworks, material manufacture, and driving heavy 
machinery on unpaved roads (Wang et al., 2025). According 
to a meta-analysis, the main occupational hazards causing 
respiratory disorders among road construction workers 
are dust, RCS, fumes, vapours, asbestos, fibres, and gases 
(Boadu et al., 2023). Excavation, tunnelling, demolition, 
sandblasting, grinding, masonry, rock drilling, road 
grading, milling, and wood processing (such as cutting, 
planing, and sanding) are among the tasks that expose 
workers to dust (Boadu et al., 2023). Handling fine particles 
of  cement, fly ash, bricks, mortar, and sandstone, as well 
as mixing cement and concrete, are common operations 
that include RCS, a particularly dangerous pollutant (US 
Department of  Labor Occupational Safety and Health 
Administration, 2024). 
Respiratory hazards are further increased by fumes, 



Pa
ge

 
20

https://journals.e-palli.com/home/index.php/ajec

Am. J. Environ. Clim. 4(3) 19-27, 2025

usually from welding, diesel exhaust, and asphalt (Kunar 
& Mandal, 2025). Road construction and repair require 
heavy machinery, most often diesel-powered. Chronic 
bronchitis and asthma are among the respiratory 
disorders linked to extended exposure to diesel exhaust 
fumes (Landwehr et al., 2023; Mo et al., 2022). Road 
construction workers, regrettably, frequently work long 
hours, increasing their exposure to dangerous materials 
and, as a result, the risk to their respiratory health (WHO, 
2021). Road construction workers frequently work long 
shifts, which increases their exposure to these dangerous 
compounds and raises their risk of  respiratory health 
problems issues (Boadu et al., 2023; Yasmeen & Hafeez, 
2023). Despite this data, there is a paucity of  studies in 
Imo State to assess the occupational respiratory risks 
of  road transport workers; hence, this study aims to 
contribute to the development of  targeted treatments 
and policies to mitigate the hazards to respiratory health 
of  road construction workers in the region. 

MATERIALS AND METHODS
Population of  the Study
The study population consisted of  all road construction 
workers employed at construction sites across Imo State, 
Nigeria. 

Study Area
This study was conducted among road construction 
workers aged 18 years and older in Imo State, located in 
the South-Eastern region of  Nigeria. With a total area of  
roughly 5,100 km2, Imo State is located between the lower 
River Niger and the upper and middle Imo River. Its 
latitudes range from 4°45’N to 7°15’N and its longitudes 
from 6°50’E to 7°25’E.

Sample Size Determination
Cochran’s formula for cross-sectional research was used to 
determine the minimal sample size (Ogbeibu, 2014):
n=(Z2 Pq)/d2  
Where p is the percentage of  construction workers having 
respiratory issues (35.5%) from a prior study (Isara et al., 
2016), q is (1-p), d is the allowable margin of  error (0.05), 
and n is the minimum sample size.
∴ n=(1.962 X 0.355 X 0.645)/0.052= 351.85= 352
A minimum sample size of  352 was established; in the end, 
353 road construction workers participated in the survey. 

Sampling Technique
The selection of  the 353 participants was conducted using 
a multistage sampling technique. Imo State was divided 
into its three senatorial zones: Imo West, Imo East, and 
Imo North, in the initial phase. The major construction 
sites in each senatorial zone’s local government areas were 
randomly selected from a compiled list of  all construction 
sites for the second stage. In the third stage, individual 
road construction workers at these sites were selected 
using simple random sampling. A total of  121, 122, and 
110 workers were recruited from Imo West, Imo East, 

and Imo North, respectively. Inclusion criteria included 
being employed as a road construction worker, being 
aged 18 years or older, and having at least six months of  
experience in the profession. Exclusion criteria included 
non-road construction workers, those who did not 
provide consent, and workers with acute illnesses. 

Method of  Data Collection
Data was collected using the following instruments:
• A structured questionnaire to capture demographic 

and health-related information.
• A sphygmomanometer measures blood pressure.
• A spirometer to assess forced vital capacity (FVC).
• Gas meters to measure ambient levels of  CO, SO₂, and 

SPM at strategic locations on construction sites.

Method of  Data Analysis
Data was entered and analyzed using the Statistical 
Package for the Social Sciences (SPSS) software, version 
23. Continuous and categorical variables were summarised 
using descriptive statistics, such as means and frequency 
distributions, respectively, and displayed in tabular form. 
With a 95% confidence interval and a significance level 
of  0.05, an analysis of  variance (ANOVA) was used to 
assess variations in ambient air pollutant concentrations 
and the frequency of  respiratory symptoms among the 
three senatorial zones.

Ethical Consent
Ethical approval was obtained from the Ethical Committee 
of  the Department of  Public Health, School of  Health 
Technology, Federal University of  Technology, Owerri, 
Imo State, Nigeria. Informed written consent was obtained 
from all participants prior to their inclusion in the study.

RESULTS AND DISCUSSION
A total of  353 male road construction workers from the 
three senatorial zones of  Imo State, Nigeria (Imo East, 
Imo West, and Imo North), participated in this study. The 
data are summarized in Tables 1–7, where “n” denotes 
the number of  participants and “%” represents the 
percentage.
Age Demographic Profile of  Road Construction Workers
This study found that all the participants (road construction 
workers) were males. There were more 31–40-year-olds 
(33.43%) and 41-50-year-olds (27.76%), compared to 
the 18-30-year-olds (17.85%), as shown in Table 1. Road 
construction is a labour-intensive industry that involves 
heavy machinery, such as tractors, cement mixers, 
bulldozers, and excavators, which emit dust and gases, 
exposing workers to hazardous pollutants (Nikolay, 2018). 
The male majority in this study was comparable to earlier 
studies on road construction workers in Ghana’s Western 
North, Ashanti, and Ahafo regions (Yankson et al., 2023). 
The preponderance of  men in construction may be due 
to the nature of  the work, which involves hard labour 
such as removing rocks and dirt, constructing pavement, 
clearing vegetation, and building embankments.



Pa
ge

 
21

https://journals.e-palli.com/home/index.php/ajec

Am. J. Environ. Clim. 4(3) 19-27, 2025

Awareness of  Air Pollution Across Senatorial Zones
Across the three senatorial zones, the majority of  
respondents strongly agreed with the following statements: 
road construction is a major source of  dust (70.21%, 
n=248), dust can cause respiratory problems (93.01%, 
n=328), road construction materials contain harmful 
chemicals (87.81%, n=310), workers should consistently 

use personal protective equipment (PPE) (87.85%, 
n=310), rain and cold weather reduce dust levels (64.06%, 
n=226), and sunny weather promotes distant air movement 
(65.31%, n=231), as shown in Table 2. However, 0.53% 
(n=4) disagreed that road construction materials contain 
hazardous chemicals, and 5.33% (n=38) disagreed that 
road construction is a significant source of  dust.

Table 1: Age Demographic Profile of  Road Construction Workers
Age group (years) Imo West n(%) Imo East n(%) Imo North n(%) Total n(%)
18-30 18(5.1) 22(5.38) 23(6.51) 63(17.85)
31-40 43(12.18) 38(10.76) 37(10.48) 118(33.43)
41-50 35(9.92) 31(8.78) 32(9.07) 98(27.76)
Above 50 25(7.08) 31(8.78) 18(5.10) 74(20.96)

Table 2: Response of  all subjects in Imo State on Air Pollution Awareness
Information on Air Pollution Strongly 

Agree (%)
Agree  
(%)

Disagree 
(%)

Strongly 
Disagree (%)

GENERAL (ALL THE THREE ZONES)
Road construction is a major source of  dust 274(70.21) 27(7.03) 38(5.33) 0(0.00)
Dust can cause respiratory health problems 303(93.01) 15(3.90) 0(0.00) 0(0.00)
Road construction materials contain harmful chemicals 322(87.81) 38(9.64) 4(0.53) 0(0.00)
Workers should always wear their PPE 311(87.85) 35(9.89) 0(0.00) 0(0.00)
Rain and cold weather reduce dust 278(64.06) 76(33.45) 0(0.00) 0(0.00)
Sunny weather promotes distant air movement 229(65.31) 40(11.30) 0(0.00) 0(0.00)
IMO WEST
Road construction is a major source of  dust 97(82.45) 7(8.50) 4(1.50) 0(0.00)
Dust can cause respiratory health problems 82(73.30) 5(5.00) 0(0.00) 0(0.00)
Road construction materials contain harmful chemicals 95(85.57) 8(7.30) 0(0.00) 0(0.00)
Workers should always wear their PPE 106(91.24) 10(9.17) 0(0.00) 0(0.00)
Rain and cold weather reduce dust 85(77.55) 10(8.86) 0(0.00) 0(0.00)
Sunny weather promotes distant air movement 94(86.90) 15(10.56) 0(0.00) 0(0.00)
IMO EAST
Road construction is a major source of  dust 90(80.45) 7(9.50) 4(1.50) 0(0.00)
Dust can cause respiratory health problems 93(88.30) 9(6.00) 0(0.00) 0(0.00)
Road construction materials contain harmful chemicals 99(85.44) 7(6.35) 0(0.00) 0(0.00)
Workers should always wear their PPE 91(84.24) 18(13.18) 0(0.00) 0(0.00)
Rain and cold weather reduce dust 90(82.50) 15(12.86) 0(0.00) 0(0.00)
Sunny weather promotes distant air movement 98(89.90) 13(10.02) 0(0.00) 0(0.00)
IMO NORTH
Road construction is a major source of  dust 87(78.45) 10(9.11) 1(1.90) 0(0.00)
Dust can cause respiratory health problems 96(90.28) 12(9.60) 0(0.00) 0(0.00)
Road construction materials contain harmful chemicals 102(95.44) 4(6.35) 0(0.00) 0(0.00)
Workers should always wear their PPE* 91(85.29) 16(12.10) 0(0.00) 0(0.00)
Rain and cold weather reduce dust 100(92.92) 11(8.30) 0(0.00) 0(0.00)
Sunny weather promotes distant air movement 88(79.43) 11(9.02) 0(0.00) 0(0.00)

*PPE: Personal Protective Equipment



Pa
ge

 
22

https://journals.e-palli.com/home/index.php/ajec

Am. J. Environ. Clim. 4(3) 19-27, 2025

Ambient Air Pollutant Levels Across Senatorial Zones
The mean concentrations of  ambient air pollutants at 
construction sites are presented in Table 3. Imo West had 
1940.50 ± 24.15 μg/m³ of  suspended particulate matter 
(SPM), Imo East had 1960.17 ± 30.79 μg/m³, and Imo 
North had 1956.68 ± 30.25 μg/m³. These variations were 
statistically significant (p<0.001). Significant differences 
(p<0.05) were also seen in the levels of  carbon monoxide 
(CO), which were 183.50 ± 2.17 ppm in Imo West, 185.34 
± 6.46 ppm in Imo East, and 187.51 ± 6.49 ppm in Imo 
North. Sulfur Dioxide (SO₂) levels were 499.17 ± 42.92 
μg/m³ in Imo West, 518.26 ± 55.12 μg/m³ in Imo East, 
and 520.14 ± 55.34 μg/m³ in Imo North, with significant 
differences (p<0.001).
Dust (soil, gravel, wood, silica, non-silica mineral, 
and demolition dust) and diesel exhaust emissions 
from heavy-duty vehicles and stationary engines are 
common pollutants found at construction sites (Toronto 
Environmental Alliance, 2024).  Carbon monoxide, 
hydrocarbons, sulphur and nitrogen compounds, 

and carbon dioxide are all present in diesel exhaust 
(Geldenhuys et al., 2022).  The measurements made for 
this study showed that the concentrations of  common 
ambient air pollutants from these common sources far 
exceeded the World Health Organization (WHO)’s 
acceptable criteria. 

Ambient SPM Levels Across Senatorial Zones
The SPM levels, particularly PM₂.₅ and PM₁₀, were 
significantly elevated in this study (Table 3). Due to their 
deep penetration into the lungs, the elevated SPM levels 
raise the risk of  lung disease, emphysema, and lung cancer 
(Cohen et al., 2005). PM₂.₅ is particularly dangerous as it 
contributes to asthma, cardiovascular disease, and early 
mortality due to its toxic components, which include 
heavy metals and carcinogenic organic compounds 
(Cohen et al., 2005). The study’s high SPM levels (1906–
1981 μg/m3) and the 158.07–1763.37 μg/m3 SPM range 
reported in Chinese building sites (Fang et al., 2025) both 
point to the urgent need for dust management measures.

Table 3: Suspended Particulate Matter (SPM) Levels at Construction Sites across Senatorial Zones in Imo State
GPS Location North GPS Location East SPM (μg/m3)
IMO WEST
5.4882o 7.0175o 1930
5.4859o 7.0171o 1906
5.4840o 7.0180o 1934
5.4833o 7.0169o 1940
5.4851o 7.0173o 1977
5.4889o 7.0182o 1956
Mean ± Standard deviations: 1940.5 ± 24.15
P-value: <0.0001
IMO EAST
5.7822o 7.0390o 1942
5.7835o 7.0388o 1956
5.7830o 7.0398o 1923
5.7846o 7.0383o 1959
5.7892o 7.0381o 1960
5.7851o 7.0398o 1941
Mean ± Standard deviations: 1960.17 ± 30.79
P-value:  0.01
IMO NORTH
5.8191o 7.3411o 1945
5.8170o 7.3406o 1933
5.8186o 7.3424o 1909
5.8198o 7.3439o 1962
5.8182o 7.3401o 1981
5.8169o 7.3453o 1963
Mean ± Standard deviations: 1956.68 ± 30.25
P-value: <0.001



Pa
ge

 
23

https://journals.e-palli.com/home/index.php/ajec

Am. J. Environ. Clim. 4(3) 19-27, 2025

Ambient CO Levels Across Senatorial Zones
Elevated CO levels portend major health risks because 
haemoglobin has a stronger affinity for CO than oxygen 
and forms carboxyhaemoglobin (HbCO), which reduces 
oxygen delivery to tissues and leads to hypoxia (Offiah 
et al., 2022). While chronic CO exposure can lead to 
melancholy, memory loss, and in extreme situations, 
central nervous system and heart poisoning or death, acute 
exposure can elicit symptoms including light-headedness, 
disorientation, headaches, and vertigo. Haemoglobin 
has a greater affinity for CO than oxygen, and forms 
carboxyhaemoglobin (HbCO), which lowers oxygen 
delivery to tissues and causes hypoxia (Offiah et al., 2022). 
This makes elevated CO levels a serious health risk. While 

chronic CO exposure can lead to melancholy, memory 
loss, and in extreme situations, central nervous system 
and heart poisoning or death, acute exposure can elicit 
symptoms including light-headedness, disorientation, 
headaches, and vertigo (Mishra & Krishnan, 2016). As 
seen in Table 4, the study’s measured CO levels (180–189 
ppm) were much higher than the maximum CO range 
of  2.10–2.27 ppm recorded at another construction site 
in Lagos State, Nigeria, and well beyond the 100ppm 
threshold considered harmful to human health (Owolabi 
et al., 2024). These disparities could have been caused by 
differences in the various geographic locations’ seasonal 
weather patterns, human activities, and meteorological 
circumstances.

Table 4: Carbon Monoxide (CO) Levels at Construction Sites across Senatorial Zones in Imo State
GPS Location North GPS Location East CO (ppm)
IMO WEST
5.4882o 7.0175o 183
5.4859o 7.0171o 181
5.4840o 7.0180o 183
5.4833o 7.0169o 182
5.4851o 7.0173o 187
5.4889o 7.0182o 185
Mean ± Standard deviations:               183.5 ± 2.17
P-value: <0.0001
IMO EAST
5.7822o 7.0390o 185
5.7835o 7.0388o 186
5.7830o 7.0398o 184
5.7846o 7.0383o 180
5.7892o 7.0381o 185
5.7851o 7.0398o 189
Mean ± Standard deviations: 185.34 ± 6.49
P-value: <0.0001
IMO NORTH
5.8191o 7.3411o 188
5.8170o 7.3406o 185
5.8186o 7.3424o 181
5.8198o 7.3439o 180
5.8182o 7.3401o 185
5.8169o 7.3453o 187
Mean ± Standard deviations: 187.51 ± 6.49
P-value:  0.02

Ambient SO₂ Levels Across Senatorial Zones
This study’s ambient SO₂ levels were significantly higher 
(p<0.001) across senatorial zones, as shown in Table 
5, which could have an impact on respiratory health. 
Although SO₂ is primarily absorbed by the upper airways’ 
mucous membranes, increased ventilation (e.g., during 
physical labour) can deliver higher doses to the lungs, 

causing bronchoconstriction, reduced lung function, and 
respiratory symptoms (Adetoun-Mustapha et al., 2011; 
Thacher et al., 2013). 
Long-term exposure to SO₂ has been linked to respiratory 
issues even at lower doses (0.4–3.0 ppm); however, 
attribution is made more difficult by confounding factors, 
including co-exposure to other pollutants (Rodney et al., 



Pa
ge

 
24

https://journals.e-palli.com/home/index.php/ajec

Am. J. Environ. Clim. 4(3) 19-27, 2025

2024). The high SO₂ values (499–520 μg/m³) in this study, 
which were higher than the average level of  17.95±7.44 
µg/m³ recorded in India (Singh et al., 2023) suggest a 

significant risk to the respiratory health of  Nigerian road 
construction workers. 

Table 5: Sulphur dioxide (SO2) Levels at Construction Sites across Senatorial Zones in Imo State
GPS Location North GPS Location East SO2 (μg/m3)
IMO WEST
5.4882o 7.0175o 460
5.4859o 7.0171o 559
5.4840o 7.0180o 453
5.4833o 7.0169o 477
5.4851o 7.0173o 510
5.4889o 7.0182o 536
Mean ± Standard deviation:            499.17 ± 42.92
P-value: <0.0001
IMO EAST
5.7822o 7.0390o 466
5.7835o 7.0388o 557
5.7846o 7.0383o 449
5.7892o 7.0381o 590
5.7851o 7.0398o 544
Mean ± Standard deviations:           518.26 ± 55.12
P-value  <0.0001
IMO NORTH
5.8191o 7.3411o 449
5.8170o 7.3406o 578
5.8186o 7.3424o 461
5.8198o 7.3439o 480
5.8182o 7.3401o 503
5.8169o 7.3453o 522
Mean ± Standard deviations: 520.14 ± 55.34
P-value: <0.0001

Prevalence of  Respiratory Health Problems Among 
Road Construction Workers
The findings of  similar studies, including Ekpenyong et 

al. and Isara et al., in Nigeria (Ekpenyong et al., 2012; Isara 
et al., 2016), and Mandal & Dutta (2022) in India which 
reported similar respiratory function impairment among 

Figure 1: Distribution of  Respiratory Health Problems among Road Construction Workers in Imo State



Pa
ge

 
25

https://journals.e-palli.com/home/index.php/ajec

Am. J. Environ. Clim. 4(3) 19-27, 2025

workers exposed to ambient air pollutants, are consistent 
with the high prevalence of  symptoms like sneezing 
(82.15%, n=290), coughing (59.77%, n=211), wheezing 
(48.16%, n=170), headache (37.68%, n=133), shortness 
of  breath (34.28%, n=121), catarrh (22.38%, n=79), sore 
throat (20.39%, n=72), pneumonia (18.70%, n=66), and 
asthma (8.22%, n=29) in this study (Figure 1).

Comparing Respiratory Health Issues Among 
Senatorial Zones
The distribution of  respiratory symptoms among 
senatorial zones is shown in Table 6. Over half  (56.50%, 

n=69) of  Imo West, 58.50% (n=75) of  Imo East, and 
56.40% (n=62) of  Imo North reported coughing. In 
Imo West, 76.45% (n=90), Imo East, 75.11% (n=88), 
and Imo North, 80.10% (n=85) of  respondents 
reported sneezing. In Imo West, 21.47% (n=24), Imo 
East, 20.32% (n=26), and Imo North, 20.72% (n=28) 
of  the population reported having diarrhoea. Headache 
was reported by 40.03% (n=45) in Imo West, 36.83% 
(n=44) in Imo East, and 42.14% (n=46) in Imo North. 
Wheezing was reported by 49.12% (n=54) in Imo West, 
44.15% (n=52) in Imo East, and 53.45% (n=55) in Imo 
North.

Table 6: Sulphur dioxide (SO2) Levels at Construction Sites across Senatorial Zones in Imo State
Health 
Problem

Imo West Imo East Imo North
n % n % N %

Cough 69 56.50 75 58.50 62 56.40
Sneezing 90 76.45 88 75.11 85 80.10
Catarrh 24 21.47 26 20.32 28 20.42
Sore throat 23 20.05 24 19.50 20 19.87
Asthma 8 6.49 10 7.32 7 5.45
Short breadth 40 35.80 42 37.59 33 29.23
Pneumonia 26 18.43 27 20.36 24 18.90
Headache 45 40.03 44 36.83 46 42.14
Wheezing 54 49.12 52 44.15 55 53.45

Comparison of  Forced Vital Capacity Values Across 
Senatorial Zones
Mean Forced Vital Capacity (FVC) values were 2263.34 
± 482.33 ml in Imo West, 2578.80 ± 751.80 ml in Imo 
East, and 2382.78 ± 610.42 ml in Imo North, as shown 
in Table 7. Seventeen workers had reduced FVC values of  

0-1000ml according to spirometry results (Table 7), which 
may indicate respiratory impairment (Mason et al., 2010). 
The workers’ infrequent FVC monitoring exposes a gap in 
occupational health surveillance, as gradual lung function 
deterioration may not be detected until serious harm is 
already done (Lynch et al., 2021; Wallbanks et al., 2024).

Table 7: Comparison of  Forced Vital Capacity values of  Road Construction Workers at different Senatorial zones
Imo West Imo East Imo North

FVC (ml) Total N % n % N %
0 – 1000 17 6 5.0 7 5.7 4 3.6
1001 – 2000 63 24 19.8 19 15.6 20 18.2
2001 – 3000 200 66 55.0 68 55.7 66 60.0
3001 – 4000 63 20 16.7 23 18.9 20 18.2
4001 – 5000 10 5 4.2 5 4.1 0 0.0
Total 353 121 100.00 122 100.00 110 100.00
Min (Max) 1250 (3270) 1190 (4118) 1885 (4491)
Mean ± Std Dev 2263.3 ± 482.3 2578.8 ± 751.80 2382.8 ± 610.4
P-value P=0.17

CONCLUSIONS
This study evaluated ambient air pollutant levels at road 
construction sites in Imo State, Nigeria, and their impact 
on workers’ respiratory health. The key findings were that 
road construction workers are exposed to high levels of  
ambient air pollutants (CO, SO₂, SPM) exceeding WHO 
safe limits. The respiratory symptoms, such as wheeze, 
sneezing, coughing, and shortness of  breath, were highly 

prevalent, with FVC values indicating compromised lung 
function in some workers. A proportion of  employees 
were ignorant of  the dust and chemical hazards associated 
with road building. These findings highlight the urgent 
need for protective measures, including mandatory high-
quality PPE, routine health monitoring with spirometry, 
and environmental controls like cleaner fuels and dust 
suppression, strict enforcement of  air quality regulations, 



Pa
ge

 
26

https://journals.e-palli.com/home/index.php/ajec

Am. J. Environ. Clim. 4(3) 19-27, 2025

and worker education awareness campaigns. Future 
research should include longitudinal studies to assess 
long-term effects, biomonitoring for health impacts, 
indoor-outdoor exposure comparisons, and comparative 
geographic comparisons in other regions to support 
national policy development. Immediate action is critical 
to safeguard workers’ respiratory health and ensure 
compliance with environmental and occupational safety 
standards.

REFERENCES 
Abdullahi, M. S. A., Abdikafi, E. A., Abdifitah, M. A., 

& Ahmed, M. H. (2022). Environmental Impact 
Assessment in construction activities for Dahab 
Tower Building Mogadishu. American Journal of  
Environment and Climate, 1(3), 1–5. https://doi.
org/10.54536/AJEC.V1I3.773

Adetoun-Mustapha, B., Blangiardo, M., Briggs, D. J., & 
Hansell, A. L. (2011). Traffic air pollution and other 
risk factors for respiratory illness in schoolchildren 
in the Niger-Delta region of  Nigeria. Environmental 
Health Perspectives, 119(10), 1478–1482. https://doi.
org/10.1289/EHP.1003099

Boadu, E. F., Okeke, S. R., Boadi, C., Osei Bonsu, E., 
& Addo, I. Y. (2023). Work-related respiratory health 
conditions among construction workers: a systematic 
narrative review. BMJ Open Respiratory Research, 10(1). 
https://doi.org/10.1136/BMJRESP-2023-001736

Bwala, J. M., Amadi, A. N., Iwuala, C. C., & Enebeli, 
U. U. (2025). Occupational health problems: An 
assessment of  the cardiovascular health status of  
road construction workers in Imo State, Nigeria. 
European Scientific Journal, 21(21), 64. https://doi.
org/10.19044/ESJ.2025.V21N21P55

Cohen, A. J., Anderson, H. R., Ostro, B., Pandey, K. 
D., Krzyzanowski, M., Künzli, N., Gutschmidt, 
K., Pope, A., Romieu, I., Samet, J. M., & Smith, K. 
(2005). The global burden of  disease due to outdoor 
air pollution. Journal of  Toxicology and Environmental 
Health. Part A, 68(13–14), 1301–1307. https://doi.
org/10.1080/15287390590936166

Ekpenyong, C. E., Ettebong, E. O., Akpan, E. E., 
Samson, T. K., & Daniel, N. E. (2012). Urban city 
transportation mode and respiratory health effect of  
air pollution: a cross-sectional study among transit 
and non-transit workers in Nigeria. BMJ Open, 2(5). 
https://doi.org/10.1136/BMJOPEN-2012-001253

Fang, X., Chang, R., Zuo, J., Zhang, W. E., Zou, Y., & 
Li, K. (2025). How do environmental and operational 
factors impact particulate matter dynamics in building 
construction? - Insights from real-time sensing. Journal 
of  Environmental Management, 380, 125098. https://
doi.org/10.1016/J.JENVMAN.2025.125098

Geldenhuys, G., Wattrus, M., & Forbes, P. B. C. (2022). Gas 
and particle phase polycyclic aromatic hydrocarbon 
emission factors from a diesel vehicle engine: Effect 
of  operating modes in a developing country context. 
Atmospheric Environment: X, 13, 100158. https://doi.

org/10.1016/J.AEAOA.2022.100158
Hasan, M. M., Basak, R., Sujan, M. H., Kabir, M. N., 

Das, D., Aritro, S. S., & Howladar, M. F. (2021). An 
assessment of  the impact of  industrialization on 
physical environment and socio-economic conditions 
around the Alipur industrial area, Bangladesh. 
American Journal of  Agricultural Science, Engineering, and 
Technology, 5(2), 309–325. https://doi.org/10.54536/
AJASET.V5I2.102

Isara, A. R., Adam, V. Y., Aigbokhaode, A. Q., & 
Alenoghena, I. O. (2016). Respiratory symptoms and 
ventilatory functions among quarry workers in Edo 
State, Nigeria. Pan African Medical Journal, 23(212). 
https://doi.org/10.11604/PAMJ.2016.23.212.7640

Kunar, S., & Mandal, G. (2025). Advanced welding technologies. 
John Wiley & Sons, Inc.; Scrivener Publishing LLC.

Landwehr, K. R., Mead-Hunter, R., O’Leary, R. A., 
Kicic, A., Mullins, B. J., & Larcombe, A. N. (2023). 
Respiratory health effects of  in vivo sub-chronic 
diesel and biodiesel exhaust exposure. International 
Journal of  Molecular Sciences, 24(6), 5130. https://doi.
org/10.3390/IJMS24065130/S1

Lynch, H. N., Goodman, J. E., & Bachman, A. N. 
(2021). Lung physiology and controlled exposure 
study design. Journal of  Pharmacological and Toxicological 
Methods, 112, 107106. https://doi.org/10.1016/J.
VASCN.2021.107106

Mandal, A., & Dutta, S. (2022). Pulmonary functions 
and work-related musculoskeletal disorders of  
road construction workers of  West Bengal, India. 
International Journal of  Occupational Safety and Health, 
12(3), 185–195. https://doi.org/10.3126/IJOSH.
V12I3.40316

Mason, R. J., Broaddus, C., Martin, T., & King, T. (2010). 
Murray and Nadel’s textbook of  respiratory medicine. 
In Murray and Nadel’s Textbook of  Respiratory Medicine 
5th ed. (5th ed.). Saunders.

Mishra, K., & Krishnan, G. (2016). Carbon monoxide 
poisoning. Journal of  Marine Medical Society, 18(2), 179. 
https://doi.org/10.4103/0975-3605.204476

Mo, S., Wang, Y., & Xiong, F. (2022). Identification and 
prioritization of  key health hazards to workers in roadway 
construction. Transportation Safety and Environment, 4(2). 
https://doi.org/10.1093/TSE/TDAC009

Nikolay, S. (2018). Types and specifics of  construction 
machines used in road pavement dismantling. 
Architecture and Engineering, 3(2). https://doi.
org/10.23968/2500-0055-2018-3-2-54-60

Offiah, A. U., Amadi, A. N., & Azuamah, Y. C. (2022). 
Measurement of  air pollutant levels and the 
occurrence of  environmental lung diseases in Umuahia 
Metropolis, Southeastern Nigeria. International Journal 
of  Science and Healthcare Research, 7(4), 128–133. 
https://doi.org/10.52403/IJSHR.20221017

Ogbeibu, A. E. (2014). Biostatistics: A practical approach to 
research and data handling (A. E. Ogbeibu, Ed.). Mindex 
Publishing Company Limited.

Owolabi, T. O. S., Ajayi, O. O., & Olofu, D. A. (2024). 



Pa
ge

 
27

https://journals.e-palli.com/home/index.php/ajec

Am. J. Environ. Clim. 4(3) 19-27, 2025

Assessment of  air pollution levels from a building 
construction site on Lagos Island. ABUAD Journal of  
Engineering Research and Development (AJERD), 7(2), 229–
235. https://doi.org/10.53982/AJERD.2024.0702.22-J

Rodney, M., Kuku, V., & Joyce, S. (2024). Indoor and 
outdoor NO2 and SO2 levels in 13 randomly selected 
preschools from 7 districts in Mpumalanga Province, 
South Africa. Public Health Challenges, 3(2), e175. 
https://doi.org/10.1002/PUH2.175

Sarabi, E. R., Poursorkhabi, R. V., & Ravanshadnia, 
M. (2025). Using the clustering method to find the 
final environmental parameters coefficients in road 
construction projects. Scientific Reports 2025 15:1, 15(1), 
1–13. https://doi.org/10.1038/s41598-025-88737-3

Singh, R., Singh, K., Sharma, A., & Rout, C. (2023). 
Assessment of  ambient air quality status at different 
railway bridge construction sites. Annals of  Biology, 
39(2), 282–287.

Thacher, J. D., Emmelin, A., Madaki, A. J. K., & Thacher, 
T. D. (2013). Biomass fuel use and the risk of  asthma in 
Nigerian children. Respiratory Medicine, 107(12), 1845–
1851. https://doi.org/10.1016/J.RMED.2013.09.009

Toronto Environmental Alliance. (2024). Types of  
Construction Pollution. Toronto Environmental Alliance. 
https://www.torontoenvironment.org/types_of_
construction_pollution

US Department of  Labor Occupational Safety and 
Health Administration. (2024). Control silica dust. 
OSHA. https://www.osha.gov/silica-crystalline

Wallbanks, S., Griffiths, B., Thomas, M., Price, O. J., & 
Sylvester, K. P. (2024). Impact of  environmental 
air pollution on respiratory health and function. 
Physiological Reports, 12(16), e70006. https://doi.
org/10.14814/PHY2.70006

Wang, G., Brandenburg, J., & Chen, D. (2025). Introduction 
to modern infrastructure construction. Taylor & Francis. 
https://doi.org/10.1201/9781003197768

WHO. (2021). WHO global air quality guidelines. World 
Health Organization. https://iris.who.int/bitstream/
handle/10665/345329/9789240034228-eng.pdf

Yankson, I. K., Karikari, A. K., Okyere, P., Koranteng, 
A., Afukaar, A. K., Otupiri, E., Donkor, P., Mock, 
C., & Owusu-Dabo, E. (2023). Occupational injuries 
among road construction workers in Ghana: Burden, 
mechanism and severity. Postgraduate Medical Journal of  
Ghana, 12(2), 101–107. https://doi.org/10.60014/
PMJG.V12I2.338

Yasmeen, R., & Hafeez, F. (2023). Effect of  particulate 
emissions on the respiratory system of  workers 
belonging to different Industries: an overview. Archives 
of  Respiratory Research, 2(1), 1–9.


