Abstract

Background: Nigeria has the largest population of any African country, with 190 million people, and has the largest economy
in Africa. Nigeria has become one of the most polluted countries in the globe as a result of recent industrial and population
development, coupled with lax regulatory enforcement and a rapid rise in the urban population. This has led to increased emissions
of particulate matter, nitrogen oxides, and other pollutants, with consequent harm to the respiratory health of many. This paper is a
systematic review of empirical research on air pollution, specifically from ozone, particulate matter, and nitrogen oxides, and their
effect on respiratory health in Nigeria.
Methods: Through systematic searching, published research on the effects of air pollution caused by ozone, particulate matter,
and nitrogen oxide on respiratory health in Nigeria were obtained from the Discover, PubMed, Google Scholar, and Web of Science
databases.
Results: In total, 3,287 publications were returned. The outcome was refined to include only studies with keywords, abstracts,
and titles in the last 10 years 27 publications returned. The studies were further appraised for relevance, quality, and studies
conducted in Nigeria only, and 11 studies were produced.
Conclusion: The effect of ozone, PM, and nitrogen oxides on respiratory health such as COPD and asthma in Nigeria has risen
in the past few years but no study on the effects of O3, PM10, and NOx on Respiratory Health (COPD and asthma) in Nigeria. This
review recommends the need for national, state, and local epidemiological data and vital strategies to mitigate the health burden
in Nigeria. Global research networks of nations with high pollution levels and scarce resources are critical for generating public
support for reducing air pollution and engaging in green technology.
Keywords: Air Pollution; Asthma; Nigeria; COPD; O3; PM; NOX
Citation: Christabel Ihedike* and Jonathan Ling. Effects of Ozone, Particulate Matter10 and Oxides of Nitrogen on Respiratory Health
(COPD and asthma) in Nigeria: A Systematic Review. LOJ Nur Heal Car 3(4)- 2022. LOJNHC.MS.ID.000166.
DOI: 10.32474/LOJNHC.20221.03.000166
LOJ Nur Heal Car. Volume 3 - Issue 4 Copyrights @ Christabel Ihedike, et al
365
has repeatedly been observed to be higher than the WHO standard,
with 9 out of 10 breathing polluted air in developing countries such
as Nigeria (WHO, 2018). Despite declines in air pollution in most
countries, poor outdoor air quality remains a major health threat
in Nigeria [2] (WHO, 2018; Global Burden of Disease, 2019; Health
Effects Institute, 2020). Because of this, this study is dedicated to a
systematic review of such problems in Nigeria.
Particulate Matter (PM): Particulate matter is composed of
microscopic liquid or solid particles that may be inhaled and have
a detrimental effect on health [3]. Particulate matter is produced
in the atmosphere resulting from chemical interactions between
various contaminants. PM is composed of organic compounds
(benzene, dioxins, polycyclic aromatic hydrocarbons, and 1-3 buta�diene) and inorganic compounds (chlorides, carbon, nitrates, met�als, and sulphates) [3]. Particle penetration is highly dependent on
their size [4]. After inhalation, particles 10μm in diameter (PM10)
may enter the lungs and potentially reach the bloodstream. PM2.5
particles, owing to their microscopic size, are associated with more
severe health consequences than PM10. Numerous studies have
shown a link between particulate matter and unfavorable health
consequences, focusing on either acute (short-term) or chronic
(long-term) PM exposure. Numerous epidemiological studies on
the health consequences of PM have been conducted. Long-term
exposure to PM is associated with cardiovascular illness and neo�natal mortality. Respiratory illnesses and immune system dysfunc�tions are widespread in Nigeria [5]. Those with asthma, diabetes,
pneumonia and cardiovascular and respiratory illnesses are more
susceptible and sensitive to the effects of PM.
Ozone: Ozone (O3
) is produced is formed by a chemical process
between nitrogen oxides and volatile organic compounds (VOCs)
emitted by natural sources and/or anthropogenic activities. It oc�curs in the stratosphere, but it may also occur due to photochemi�cal smog chain reactions in the troposphere [6]. Ozone levels above
cities are modest compared to the increasing levels in metropolitan
regions in Nigeria. Ozone is typically absorbed via inhalation and
also interferes with the function and integrity of the skin barrier.
Ozone’s toxic effects have been documented in metropolitan areas
worldwide, producing morphologic, biochemical, immunological,
and functional problems [7-10].
Nitrogen Oxide: Nitrogen oxide is a contaminant associated
with traffic as it is produced by automobile engines [11,12]. It is
a respiratory irritant that penetrates deeply into the lung, caus�ing respiratory problems such as coughing, dyspnoea, wheezing,
bronchospasm, and pulmonary edema at high concentrations. Con�centrations over 0.2ppm lead to detrimental effects in humans. In
comparison, concentrations greater than 2ppm appear to impact
T-lymphocytes, especially CD8+ and NK cells, responsible for im�munological response [12]. Lengthy exposure to high levels of ni�trogen dioxide has been implicated in the development of chronic
lung illness as well as irritation of the eyes, throat, and nose [13].
This study conducted a laborious review of existing studies that
have reported on the effect of Ozone, Particulate Matter10, and Ox�ides of Nitrogen on Respiratory Health (COPD and asthma) in Nige�ria with the aim of recognising and generating an understanding of
the effect of these pollutants of COPD and asthma.
Methodology
Systematic reviews
A comprehensive and exhaustive overview of recent literature
collected from multiple databases and relating to a research top�ic is given in systematic reviews. The papers were retrieved from
Scopus, PubMed, Discover, Google Scholar, and Web of Science da�tabases.
Eligibility
Studies examining respiratory impacts (NOx
, PM, and O3
) on
humans were considered. All the studies considered looked at the
effect of air pollution on respiratory health, which a special interest
in particulate matter, nitrogen oxides, and ozone in Nigeria. Dupli�cates of studies were eliminated, and abstracts were independently
reviewed, with any disputes addressed by bringing in a second in�vestigator. The final studies were chosen by inclusion criteria that
have tried to regulate the main confounding factors (such as mete�orological trends and season and smoking and prevailing medical
issues for cohorts) and had recorded respiratory health outcomes.
The research did not put any limitations on research design; how�ever, only publications in English were included.
Search Strategy
Search strategy and selection criteria: A systematic search
of the literature on the effect of air pollutants (O3
, PM10 and NOx
)
on COPD and asthma was conducted. The following databases were
searched: PubMed, EMBASE, and Discover. Peer-reviewed journals
and panel papers from organizations on air pollution associated
with O3
, PM10, and NOx
were reviewed.
Inclusion criteria:
To achieve the aim of this systematic review, the following cri�teria were used in the selection of the relevant publications and
reports.
a) There were no restrictions on publication dates and online
database search to include studies conducted on same air pol�lutants.
b) The study reported any effect of O3
, PM10 and NOx
associated
with COPD and asthma conditions in Nigeria.
c) The study adopted a quantitative research method.
The search on Discover, PubMed, Web of Science, EMBASE, and
Biomedical databases, on all peer-reviewed time series and pub�lished panel papers, produced a total of 3,287 articles. The outcome
was refined to include only studies with keywords, abstracts, and
titles. Subsequently, abstracts and titles of studies included were
reviewed for relevance so that studies without the effect of O3
, PM10,
and NOx