Assessment of Air Pollution Levels from Transportation Activities in Onitsha, Anambra State

CHAPTER ONE

1.0 Introduction

Air pollution has become one of the most pressing environmental challenges in urban areas around the world. In developing countries like Nigeria, rapid population growth and increased vehicular movement have intensified air quality problems. Transportation contributes a significant share of air pollutants, including carbon monoxide, nitrogen oxides, sulfur dioxide, and particulate matter. These pollutants not only degrade environmental quality but also pose serious health risks such as respiratory infections, heart diseases, and reduced visibility.

Onitsha, located in Anambra State, is one of Nigeria’s busiest commercial cities. Its high population density and constant flow of vehicles make it a hotspot for air pollution. According to Okoye and Nwosu (2022), Onitsha consistently records some of the highest air pollutant levels in West Africa, primarily due to heavy traffic and poorly maintained vehicles. Assessing air pollution levels from transportation activities in Onitsha is essential for understanding the city’s environmental condition and guiding effective air quality management.

1.1 Background to the Study

Transportation is essential for the movement of people, goods, and services, yet it remains one of the major contributors to urban air pollution. Emissions from cars, trucks, buses, and motorcycles release harmful gases and fine particulates into the atmosphere. These pollutants affect human health, damage infrastructure, and contribute to climate change.

In Nigeria, many vehicles operate without proper emission control systems. Fuel combustion efficiency is often low due to the use of old engines and poor fuel quality. In densely populated cities such as Onitsha, this problem is worse because of traffic congestion, inadequate road networks, and informal transport systems. Eneh and Agbo (2021) observed that transportation-related air pollution has increased respiratory illnesses among Onitsha residents, particularly traders and commuters exposed to roadside emissions.

Evaluating the concentration and distribution of pollutants such as carbon monoxide (CO), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and particulate matter (PM₁₀ and PM₂.₅) helps determine the city’s air quality status. The findings of this study can support urban planners and environmental agencies in designing policies that promote sustainable transport systems and cleaner air.

1.2 Statement of the Problem

Air pollution from transportation has reached critical levels in many Nigerian cities, including Onitsha. The increasing number of vehicles, coupled with traffic congestion and poor maintenance culture, has led to a steady rise in air contaminants. Residents who live or work near busy roads experience prolonged exposure to toxic fumes. Despite these issues, monitoring and control measures remain limited in most urban centers.

Onitsha’s air quality situation is particularly alarming because of its high commercial activity and vehicle density. Although some studies have highlighted pollution in the Niger Delta and Lagos, comprehensive assessments of air pollution in Onitsha are still scarce. Therefore, this study focuses on quantifying air pollutant levels resulting from transportation activities and comparing them with established air quality standards to determine their implications for human health and environmental sustainability.

1.3 Aim and Objectives of the Study

The main aim of this study is to assess air pollution levels resulting from transportation activities in Onitsha, Anambra State.

The specific objectives are to:

1. Identify major transport routes and high-traffic areas in Onitsha.

2. Measure concentrations of selected air pollutants in these locations.

3. Compare observed pollutant levels with national and international air quality standards.

4. Recommend strategies for reducing transportation-related air pollution in Onitsha.

1.4 Research Questions

1. Which areas in Onitsha experience the highest levels of air pollution due to transportation activities?

2. What are the concentrations of key air pollutants such as CO, NO₂, SO₂, and PM in these locations?

3. How do the measured levels compare with WHO and NESREA air quality standards?

4. What measures can effectively reduce vehicular emissions and improve air quality in Onitsha?

1.5 Significance of the Study

This study provides critical insights into the relationship between transportation activities and air pollution in Onitsha. The findings will assist environmental protection agencies, urban planners, and policymakers in implementing emission control measures and promoting eco-friendly transport alternatives. It also supports Sustainable Development Goal (SDG) 11, which focuses on sustainable cities, and SDG 13, which promotes climate action.

Moreover, the research will raise public awareness about the health risks associated with air pollution and encourage the use of cleaner fuels, regular vehicle maintenance, and improved public transport systems. It contributes valuable data for future air quality monitoring and policy formulation in Nigeria.

1.6 Scope of the Study

The study focuses on selected high-traffic routes in Onitsha, including Upper Iweka, Main Market, and Awka Road. It assesses air pollutants such as carbon monoxide (CO), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and particulate matter (PM₁₀ and PM₂.₅). The study does not cover industrial or domestic air pollution sources. Field measurements and observations will be conducted during peak and off-peak traffic hours to determine pollution variation.

1.7 Definition of Key Terms

• Air Pollution: The presence of harmful substances in the atmosphere that pose health and environmental risks.

• Transportation Emissions: Pollutants released into the air as a result of fuel combustion in vehicles.

• Particulate Matter (PM): A mixture of tiny solid and liquid particles suspended in the air, often harmful when inhaled.

• Carbon Monoxide (CO): A colorless, odorless gas produced by incomplete combustion of fossil fuels.

• Air Quality Standards: Regulatory limits set to maintain safe and healthy air conditions.

References

Eneh, A. C., & Agbo, K. C. (2021). Transportation emissions and air quality degradation in Onitsha, Nigeria. Journal of Environmental Research and Development, 16(2), 91–104.
Okoye, T. U., & Nwosu, F. E. (2022). Urban air pollution dynamics in major Nigerian cities: The case of Onitsha. African Journal of Environmental Studies, 14(3), 55–70.
Ude, O. N., & Olisa, J. P. (2023). Assessment of vehicular emissions and health implications in Southeast Nigeria. Environmental Science and Health Perspectives, 11(1), 33–49.