AN EXAMINATION OF THE SOURCES OF BLACK SOOT AND THEIR IMPACT ON AIR QUALITY IN PORT HARCOURT, RIVERS STATE, NIGERIA

CHAPTER ONE INTRODUCTION 1.1 Background of the Study Black soot—also referred to as black carbon—is a major environmental pollutant that has raised global concern due to its significant impact on air quality, public health, and climate change. It primarily consists of fine particulate matter (PM2.5) formed from the incomplete combustion of carbon-based fuels like wood, diesel, coal, and other fossil fuels (Bond et al., 2013). These microscopic particles are small enough to enter deep into the lungs and potentially reach the bloodstream, leading to a range of serious health issues, such as respiratory and cardiovascular diseases (World Health Organization [WHO], 2018). The issue is particularly pronounced in areas where sources such as industrial emissions, vehicle exhaust, gas flaring, and illegal artisanal refining are widespread (Gani et al., 2020). Worldwide, black soot contributes significantly to poor air quality and is a key component of urban air pollution. It is linked to millions of premature deaths each year due to its harmful effects on respiratory and cardiovascular health (Lelieveld et al., 2015). While developed countries have introduced strict regulations to reduce emissions from industries and transport, many developing nations, including Nigeria, still struggle with lax enforcement, exposing populations to higher levels of black soot and its health-related consequences (Anenberg et al., 2017). The major contributors to black soot emissions include diesel-powered vehicles, burning of solid fuels for cooking and heating, open incineration of agricultural waste, and industrial processes (Bond et al., 2015). In urban areas, traffic congestion and industrial activity further exacerbate air pollution. Nigeria, especially its urban and industrial regions, is severely affected by black soot pollution. The Niger Delta, for example, faces critical air quality challenges due to extensive gas flaring, illegal oil refining, and industrial emissions (Ukpebor et al., 2020). In recent years, Port Harcourt has witnessed a sharp increase in black soot concentration, visibly noticeable through layers of black dust settling on various surfaces across the city. Gas flaring—an issue that has persisted for decades in the Niger Delta—contributes substantially to black soot through the burning of hydrocarbon gases (Ekpete & Konne, 2021). Similarly, illegal refining of crude oil using rudimentary methods has emerged as another major source of black carbon, emitting large quantities of pollutants that significantly degrade air quality and pose serious public health risks. Previous studies have shown a clear link between black soot exposure and various health problems, including asthma, bronchitis, lung cancer, and other respiratory conditions (Ukpebor et al., 2020). The economic implications are equally troubling, as increased healthcare costs and reduced worker productivity due to illness place a strain on both individuals and the economy. Despite these concerns, there is limited research that specifically examines how different sources contribute to black soot pollution in Nigeria, making it difficult to implement targeted air quality interventions. The connection between black soot and air pollution is well established, with PM2.5 serving as a key indicator of pollution levels (WHO, 2018). Aside from affecting health, black soot also contributes to environmental degradation. When it settles on surfaces like snow and ice, it reduces their reflectivity (albedo), accelerating melting and contributing to climate change (Bond et al., 2015). As a climate forcer, black soot ranks second only to carbon dioxide in its warming effect on the atmosphere. In Nigeria, the prevalence of black soot is exacerbated by human activities and a lack of effective environmental regulations. Weak enforcement has allowed gas flaring and illegal oil refining to thrive, worsening the pollution problem. Given that the Niger Delta is one of the most heavily polluted areas in the country, it is crucial to understand the specific sources of black soot emissions in order to develop efficient air quality management strategies (Ekpete & Konne, 2021). Although the adverse health and environmental impacts of black soot are well documented, comprehensive research evaluating the relative contribution of each pollution source in Nigeria is scarce. For this reason, this study aims to investigate the sources of black soot in Port Harcourt and assess their contribution to the region’s deteriorating air quality. 1.2 Statement of the Problem Black soot has become a pressing environmental concern, especially in regions marked by industrial activity, gas flaring, and illegal oil refining. This pollutant, composed of fine particles (PM2.5) and carbon, originates mainly from incomplete combustion (World Health Organization [WHO], 2018). It arises from various sources, including industrial discharge, vehicle exhaust, biomass burning, and crude oil processing outside legal frameworks. These activities degrade air quality and expose residents to significant health risks (Ukpebor et al., 2020). In cities like Port Harcourt, the black soot issue is made worse by ongoing illegal refining and gas flaring, leading to an alarming rise in atmospheric particulate matter (Ekpete & Konne, 2021). Long-term exposure to black soot is linked to numerous health challenges such as asthma, bronchitis, and increased mortality (WHO, 2018). However, little research has been done to quantify how each source contributes to the city’s overall air pollution levels. This lack of data makes it difficult to design targeted strategies to reduce pollution. Therefore, this study seeks to analyze the various sources of black soot and how they impact air quality in Port Harcourt, Rivers State, Nigeria. 1.3 Objective of the Study The overarching goal of this study is to examine the sources of black soot and their impact on air quality in Port Harcourt, Rivers State, Nigeria. The specific objectives are to: i. Identify the main contributors for black soot pollution in Port Harcourt, Rivers State. ii. Assess the health implications of black soot exposure on residents of Port Harcourt. iii. Propose practical strategies to reduce black soot emissions and improve air quality in the city. 1.4 Research Questions This study will be guided by the following research questions: i. What are the main contributors to black soot pollution in Port Harcourt, Rivers State? ii. What are the health implication of exposure to black soot among residents of Port Harcourt? iii. What strategies can be implemented to reduce black soot emissions and improve air quality in Port Harcourt? 1.5 Significance of the Study The findings from this research will be valuable for policymaking by providing empirical evidence needed to shape air quality regulations. Identifying the most significant sources of black soot pollution will help decision-makers develop targeted policies to control emissions from critical sources such as industries, vehicles, and unauthorized oil refining operations. This will support more efficient resource allocation for air quality improvement and pollution mitigation. Additionally, the study will contribute to academic knowledge by filling a gap in the existing literature. It will serve as a valuable resource for libraries and offer a foundation for future research on related topics. 1.6 Scope of the Study This research focuses on identifying the sources of black soot and evaluating their role in the deterioration of air quality in Port Harcourt, Rivers State, Nigeria. It will specifically investigate the primary contributors to black soot, assess the health risks associated with exposure, and recommend strategies to reduce emissions and enhance air quality. Geographically, the study is limited to Port Harcourt, Rivers State, Nigeria. 1.7 Limitations of the Study As with any research effort, this study faced a few limitations: Time Constraints: The researcher had to juggle academic responsibilities such as attending classes alongside conducting the study, which affected the available time. Financial Challenges: The cost of data collection, printing, typesetting, and accessing relevant materials posed financial burdens. Limited Availability of Materials: Accessing sufficient literature on black soot in the Nigerian context was challenging due to the relatively limited number of studies on the topic. 1.8 Definition of Terms Black Soot: Also called black carbon, this is made up of fine particles resulting from the incomplete combustion of carbon-based fuels such as coal, diesel, and wood. It appears as black dust and is a key air pollutant linked to health and environmental problems. Air Quality: Refers to the level of cleanliness or pollution in the air, often measured through the presence of substances like PM2.5, carbon monoxide, nitrogen oxides, sulfur dioxide, and ozone. High-quality air means it is clean and safe for breathing. Particulate Matter (PM2.5): These are microscopic particles less than 2.5 microns wide. Due to their small size, they can deeply penetrate the lungs and causing serious health issues. Gas Flaring: The burning of natural gas that is released during oil extraction. While it is done to manage pressure or dispose of waste gases, it also releases harmful pollutants, including black soot. Artisanal Refining: This is an informal and unauthorized method of refining crude oil using basic tools and techniques. It contributes significantly to air pollution due to the uncontrolled burning of crude products. Industrial Emissions: These are pollutants released into the atmosphere from factories and manufacturing plants. They include black soot, harmful gases, and other toxic substances that contribute to air pollution.