Health and Environmental Effects of Ambient Air Pollution: Volume 1: Air Pollution, Human Health, and the Environment

By Rama Rao Karri

Health and Environmental Effects of Ambient Air Pollution is part of a series of three volumes for Air Pollution, Human Health, and the Environment. Volume 1 discusses the adverse consequences of ambient air pollutants on human health, animals, plants, and structures. This book examines the production of ambient air pollutants in the environment. It begins with an overview of the classifications, sources, and occurrences of outdoor air pollutants. This book covers meteorological, climate, and topographical factors affecting air pollution, discusses how urbanization and industrialization affect air quality, and explores how climate conditions like global warming, acid rain, and airborne particulate matter impact human health. It also looks at epidemiology studies and socioeconomic aspects of outdoor air pollution, estimating health and cost effects, air quality indices, guidelines, standards, and information networks of ambient air pollutants. With contributors from experts in the field, this book is a valuable reference for academicians, researchers, and students in environmental health, public health, and occupational health, as well as environmental engineers, meteorologists, epidemiologists, medical researchers, and environmental toxicologists.

• Discusses both causes of ambient air pollution and the toxicological impact on human health
• Covers the health risk assessment of ambient air with an emphasis on the elements, exposure, and risk management
• Examines air quality management and other ambient air pollution solutions
• Discusses the environmental effects of ambient air pollutants like climate change and global warming
• Examines the epidemiology studies, estimating health and cost effects

• Language: English
• Publisher: Academic Press
• Release date: Apr 2, 2024
• ISBN: 9780443160899

Book preview

Introduction

Mohammad Hadi Dehghani, Rama Rao Karri, Teresa Vera and Salwa Kamal Mohamed Hassan

This first volume of the trilogy on air pollution focuses on its effect on health and environmental effects, a widespread problem. Air pollution does not know boundaries, and because of that, it is important to continue improving our knowledge about the sources, the effects on human health, and the environment that our activities have.

The 13 chapters that form this volume are structured to cover most of the main aspects of air pollution worldwide. Therefore, as expected when a scientific subject is addressed, Chapter 1 is the Classification, sources and occurrence of outdoor air pollutants, an obligatory introduction to the starting point when facing the study of air pollution. From here, the chapters dedicated to specific problems begin. It should be noted that this book does not intend to cover all the aspects and problems that air pollution causes on health and the environment, but rather to give an overview of what they are, reviewing what has been studied so far and proposing solutions whenever possible.

In that line, Chapter 2 is about the effects of particulate matter on human health since it is known that this is one of the most important health problems that must be addressed worldwide. It starts from the definition of particulate matter, considering the different types and continuing to the adverse health problems that these tiny particles can cause in the different parts of the human body that have, therefore, a variety of diseases and health problems.

Chapter 3 is focused on the effects of outdoor air pollutants on plants and agricultural productivity. It is important to remember that air pollutants affect not only human health but also the environment and, therefore, agriculture. Human beings need agriculture to feed themselves. The effects of air pollution on agricultural productivity due to land use changes and/or intensification of activities, among other issues, need to be studied to provide new options or solutions for removing pollutants, microorganisms, and so on.

Among the classical problems related to air pollution is the acidification of rain. Even though the study of this problem started in the last century, it still needs to be considered since it is unsolved. Acid precipitation, related to the presence of sulfur and nitrogen oxides in the atmosphere, can cause environmental problems but also health effects. Measures to minimize its impact must be taken worldwide, as shown in Chapter 4.

Human activities have led to a worrying increase in the earth’s surface temperature. Global warming, directly and indirectly, affects the environment, health, and human survival on Earth. Extreme weather events, such as fires, floods, extreme rains, or droughts, are all related to this problem. Moreover, it also causes respiratory disorders, neurological illnesses, and some kinds of cancers. Chapter 5 reviews from the basis, the importance of this worldwide problem affecting human health, including mental health, such a very important issue nowadays, environment, biodiversity, and so on. Some mitigation and adaptation strategies are proposed that can be used as ideas to implement.

Continuing with the particle matter problems introduced in Chapter 2, Chapter 6 focused on the age-specific gender-based deposition of size segregated particle matter in the human respiratory tract. In that case, it is a pioneering research subject that offers new ways to study the consequences and effects of air pollution on human health, combining simulation with field studies.

The COVID-19 outbreak shocks the world producing a global health crisis. Chapter 7 reviews the impact of air pollution on COVID-19 outcomes worldwide. It is a complex mechanism involving various factors (social distance and the role of air pollution). Because of that, as the authors stated, air pollution cannot be ignored as a confounding variable in COVID-19 propagation.

Chapter 8 is an example considering one of the most polluted hotspots in the world. It is a review on the outdoor air pollutants in the Indo-Gangetic Plains of India: sources, health effects, and remediation. In it, not only the problems of the rapid urbanization of that area are reviewed but also the increase in air pollution due to industrial activities and the effect that all have on the inhabitant’s health. The chapter ends with mitigations and recommendations that can be adapted to other areas worldwide.

One aspect that can not be forgotten is the socioeconomic aspects of outdoor air pollution, the aim of Chapter 9. As reviewed in this chapter, the socioeconomic significance of air pollution might be more noticeable in developing countries. As shown in this chapter, social and economic development must be harmonized with environmental aspects.

The effects of urbanization and industrialization on air quality are reviewed in Chapter 10. This chapter studied the urban-industrial air pollution in three different geographical areas, China, the United Kingdom, and Thailand, with different industrialization maturities. Besides, some proposals to mitigate industrial atmospheric pollution are proposed.

The Outdoor air pollution due to transportation, landfill, and incinerator is assessed in Chapter 11 since these kinds of operations have been found to release a significant amount of pollutants into the atmosphere. Considering that the atmosphere is the major environmental compartment (compared to land and water) with no boundaries, activities that cause air pollution affect not only the location where it is realized but also some other places far away, as is reviewed in this chapter.

Chapter 12 is a jack of all trades in terms of air pollution. The introduction to meteorology, weather and climate can be at the beginning or the end, but it has to be in a book focused on air pollution. As it is said, Meteorology enables the prediction and mitigation of the effects of weather and climate on humans and nature by elucidating the intricate interactions among the atmosphere, seas, and land.

Chapter 13, Impact of the changing climate on air pollution and heat stress—a comprehensive review, reviewed the potential effects of climate change, ecological disruptions, and human health (among others) on air pollution and heat stress. The impact of these environmental stressors is higher over the most vulnerable communities -identified in the chapter- and ideas for mitigation and adaptation plans are needed to reduce it.

It has been an honor to work in the preparation of this volume. It covers most of the key aspects related to outdoor air pollution: sources, sinks, transport, meteorology, effects on human health, socioeconomic impacts, etc. Much more work has to be done; however, this book is a very interesting starting point to be aware of air pollution and the work done up to now. The future is still unwritten, and we hope all these studies are considered to improve our world.

Finally, our heartfelt thanks to all the reputable authors, elite reviewers, and editorial team of Elsevier, who handhold us in every stage of conceptualization, proposal revision, initiation, operation, and completion of the book, including the production process.

Chapter 1

Classification, sources, and occurrence of outdoor air pollutants: a comprehensive overview

Rama Rao Karri¹, Teresa Vera², Salwa Kamal Mohamed Hassan³, Mamdouh I. Khoder³, Mohammad Hadi Dehghani⁴,⁵, Nabisab Mujawar Mubarak¹ and Gobinath Ravindran⁶,    ¹Petroleum and Chemical Engineering, Faculty of Engineering, Universiti Teknologi Brunei, Bandar Seri Begawan, Brunei Darussalam,    ²EUPHORE Lab, Fundación CEAM, Paterna, Spain,    ³Air Pollution Research Department, Environment and Climate Change Research Institute, National Research Centre, Dokki, Giza, Egypt,    ⁴Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran,    ⁵Center for Solid Waste Research, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran,    ⁶Department of Civil Engineering, SR University, Warangal, Telangana, India

Abstract

Outdoor air pollutants exert a profound impact on environmental quality and public health, necessitating a comprehensive understanding of their classification, sources, and occurrence. This review article delves into the intricate realm of outdoor air pollutants, elucidating their diverse categories and origins and shedding light on their complex distribution patterns. Detailed discussions on the health implications, measurement techniques, and regulatory standards provide insights into their varying influences on human health and environmental well-being. Concurrently, examining noncriteria pollutants, including volatile organic compounds, polycyclic aromatic hydrocarbons, and heavy metals, further unravels the intricacies of outdoor air quality management. Unveiling the sources of outdoor air pollutants unfurls an intricate interplay of anthropogenic and natural origins. Anthropogenic sources, ranging from vehicular emissions and industrial processes to agricultural activities and residential combustion, are dissected for their specific contributions. The review also delves into natural sources such as volcanic eruptions, forest fires, and biogenic emissions, elucidating their roles in the global atmospheric chemical milieu. Overall, this review article encapsulates a comprehensive panorama of outdoor air pollutants, fostering an appreciation for their complexities and prompting a call to action for sustainable air quality management in an increasingly urbanized and interconnected world.

Keywords

Classification; sources and occurrence; outdoor air pollutants; outdoor air quality; well-being

Acronyms and molecular formulas

BVOCs Biogenic volatile organic compounds

CO Carbon monoxide

COPD Chronic obstructive pulmonary disease

EPA Environmental Protection Agency

HAPs Hazardous air pollutants

H2S Hydrogen sulfide

Hg Mercury

NH3 Ammonia

NO Nitric oxide

NO2 Nitrogen dioxide

NOx Nitrogen oxides

N2O Nitrous oxide

O3 Ozone

Pb Lead

PM Particulate matter

POPs Persistent organic pollutants

SO2 Sulfur dioxide

VOCs Volatile organic compounds

WHO World Health Organization

1.1 Introduction

Outdoor air pollutants constitute a critical component of the Earth’s atmospheric composition, with far-reaching implications for environmental sustainability and public health.¹ As industrialization and urbanization surge forward, accompanied by escalating vehicular emissions, energy consumption, and various anthropogenic activities, the abundance of outdoor air pollutants has risen to alarming levels.²,³ These pollutants encompass a diverse array of particles, gases, and compounds that infiltrate the atmosphere, exerting complex and often detrimental effects on both natural ecosystems and human populations.

Each year, 3.2 million people die prematurely from illnesses attributable to household air pollution caused by the incomplete combustion of solid fuels and kerosene used for cooking (see Fig. 1.1). Prolonged exposure to these pollutants can contribute to various health issues, including respiratory diseases, heart diseases, and even premature death. Among these 3.2 million deaths from household air pollution exposure, 32% are from ischemic heart disease, 23% are from stroke, 21% are due to lower respiratory infection, 19% are from chronic obstructive pulmonary disease (COPD), and 6% are from lung cancer.⁵–⁸

Figure 1.1 Review of deaths associated with air pollution.⁴

The ubiquity of outdoor air pollutants transcends geographical boundaries and socio-economic disparities, making it a global concern. Urban centers, often characterized by high population densities and intensified industrial operations, experience the brunt of these pollutants, leading to concerns about air quality and its immediate and long-term consequences on public health. Not only do these pollutants degrade the aesthetic value of the environment, but they also contribute to the deterioration of air quality, visibility, and overall well-being. The interplay between outdoor air pollutants and atmospheric processes further underscores their significance, as pollutants can be transported over long distances and impact regions far from their original sources.

The significance of outdoor air pollutants extends beyond their immediate effects, permeating into various sectors of society, including health, economics, and policy.⁹ The complex chemistry of pollutants can lead to the formation of secondary pollutants, exacerbating the challenge of controlling their impact. Additionally, as pollutants interact with sunlight, they contribute to the formation of ground-level ozone, a key component of smog and a major respiratory irritant.¹⁰ By understanding the significance of outdoor air pollutants and their multifaceted effects, stakeholders can make informed decisions and collaborate on strategies to curb emissions, improve air quality, and safeguard the planet’s environmental equilibrium and human well-being.¹⁰–¹²

1.1.1 Importance of understanding classification, sources, and occurrence

Criteria pollutants are those regulated by environmental agencies due to their detrimental impact on human health and the environment. These pollutants include particulate matter (PM), sulfur dioxide (SO2), nitrogen oxides (NOx), carbon monoxide (CO), ozone (O3), and lead (Pb).¹³,¹⁴ PM refers to tiny airborne particles, with PM2.5 (particles with a diameter of 2.5 µm or smaller) and PM10 being common examples.¹⁵,¹⁶ SO2 arises from combustion processes, such as burning coal, and NOx results from vehicle emissions.¹⁷ CO, primarily from vehicle exhaust, can impair oxygen transport in the body. Ozone, a secondary pollutant, forms when NOx and volatile organic compounds (VOCs) react in the presence of sunlight. Pb, once found in gasoline, is now predominantly emitted from industrial sources.

Noncriteria pollutants encompass a broader range of substances that may not have specific regulations but can still pose risks.¹³ These include VOCs, persistent organic pollutants (POPs), heavy metals like mercury (Hg), and endocrine-disrupting chemicals. VOCs can originate from sources like vehicle emissions and industrial processes. They can contribute to smog formation, and there is also a contribution that comes from natural sources (emissions from plants, forests, seas, etc.). POPs, such as polychlorinated biphenyls and certain pesticides, resist degradation and accumulate in the environment, potentially causing long-term harm.¹⁸,¹⁹ Mercury, emitted from coal-fired power plants, can accumulate in aquatic systems and harm fish and their consumers. Endocrine-disrupting chemicals interfere with hormonal systems in humans and wildlife, with bisphenol A being a notable example of plastics.²⁰,²¹

The intricate web of outdoor air pollutants underscores the vital importance of comprehending their classification, sources, and occurrence patterns. Effective air quality management necessitates a systematic approach that hinges on identifying, characterizing, and addressing the diverse pollutants.²² Classification plays a pivotal role in this process, as it allows for prioritizing pollutants based on their health impacts, chemical properties, and prevalence. By discerning criteria pollutants from noncriteria pollutants and delving into the specific characteristics of each category, policymakers and researchers can tailor mitigation strategies to target the most pressing concerns. This classification-driven approach enables resource allocation and regulatory efforts to be directed toward pollutants with the greatest potential for harm, optimizing the impact of interventions.

Understanding the sources of outdoor air pollutants is equally paramount, given that effective control strategies can only be developed when the origins of pollutants are well-characterized.²³–²⁵ Anthropogenic sources arising from human activities are within our sphere of influence and offer opportunities for targeted intervention. By identifying emissions from sectors such as transportation, energy production, and industrial processes, society can implement emission controls, technology upgrades, and shifts toward cleaner energy sources. Similarly, acknowledging the role of natural sources, such as wildfires and volcanic emissions, is crucial for assessing their contribution to pollution levels and understanding their variability over time. Without a comprehensive understanding of these sources, efforts to mitigate outdoor air pollutants would lack precision and may result in suboptimal outcomes.

The occurrence patterns of outdoor air pollutants tie together classification and sources, reflecting the interplay of emissions, atmospheric processes, and human activities. Geographic factors, meteorological conditions, and topographical features all influence the dispersion and concentration of pollutants in the atmosphere. Recognizing the occurrence patterns allows for identifying pollution hotspots, areas at heightened risk due to localized emissions, and atmospheric dynamics. Moreover, understanding the transport of pollutants over regional and even global scales is essential for appreciating the interconnected nature of air quality challenges. By grasping the intricacies of occurrence patterns, stakeholders can strategize spatially targeted interventions and prepare for potential transboundary impacts, contributing to improved air quality and a healthier future.

1.1.2 Purpose and scope of this review chapter

The primary purpose of this review chapter is to provide a comprehensive and authoritative synthesis of the intricate landscape surrounding the classification, sources, and occurrence of outdoor air pollutants. In a world grappling with escalating urbanization, industrial expansion, and environmental degradation, this review seeks to elucidate the complexities of outdoor air pollutants and their far-reaching implications. By consolidating and analyzing a diverse range of scientific literature, empirical studies, and regulatory frameworks, this article aims to foster a deeper understanding of these pollutants’ multifaceted dimensions.

The scope of this review article encompasses a broad spectrum of pollutants, ranging from well-known criteria pollutants such as PM2.5, NOx, and ozone to emerging noncriteria pollutants like VOCs and heavy metals. By delving into the classification of these pollutants, their unique characteristics, and their respective health and environmental impacts, the review aims to equip readers with a comprehensive knowledge base. The exploration of both anthropogenic and natural sources further widens the scope, allowing for a holistic understanding of the origins of outdoor air pollutants. This scope extends beyond terrestrial boundaries to encompass the atmospheric transport and dispersion mechanisms that shape the spatial distribution of pollutants, thereby offering insights into regional and global pollution dynamics.

Furthermore, this review article seeks to bridge the gap between scientific knowledge and practical applications. Exploring regulatory frameworks, technological advancements, and mitigation strategies complements the synthesis of existing research. By examining the measures that governments, industries, and communities can adopt to curb emissions and improve air quality, the article aspires to guide informed decision-making and stimulate proactive initiatives. Ultimately, the overarching goal of this review is to contribute not only to the scientific discourse on outdoor air pollutants but also to inspire meaningful actions that safeguard both the environment and public health.

1.2 Classification and types of outdoor air pollutants

Outdoor air pollutants can be categorized into various classes based on their chemical nature, sources, and environmental and human health impacts.²⁶ Among these, toxic pollutants are crucial indicators of air quality, reflecting the intricate interplay between emissions, atmospheric processes, and health outcomes (see Fig. 1.2). PM with aerodynamic diameters of 2.5 µm or smaller (PM2.5) and 10 µm or smaller (PM10) are central to this classification.²⁸ PM2.5, often referred to as fine particles, is a complex mixture consisting of solid particles and liquid droplets suspended in the air.²⁹ These microscopic particles can penetrate the respiratory system, posing cardiovascular and respiratory disease risks.³⁰ PM10, slightly larger, also carries health implications, particularly for individuals with preexisting conditions.³¹,³²

Figure 1.2 Sources and composition of PM, SOx, NOx, and VOCs.²⁷

Nitrogen oxides (NOx) represent another key criteria pollutant, encompassing nitrogen dioxide (NO2) and nitric oxide (NO) among the most significant pollutants.³³ These compounds originate from combustion processes in vehicles, power plants, and industrial facilities.³⁴ NO2, a reddish-brown gas with an acrid odor, has been linked to respiratory problems and contributes to the formation of ground-level ozone, a secondary pollutant.³⁵,³⁶ Sulfur dioxide (SO2) is predominantly emitted from fossil fuel combustion, particularly in industrial settings. SO2 can cause respiratory and cardiovascular issues and contribute to PM formation.³⁶,³⁷ Ground-level ozone (O3) is a secondary pollutant formed through complex photochemical reactions involving precursor pollutants like NOx and VOCs. Despite its beneficial presence in the stratosphere, ozone poses respiratory challenges when present in elevated concentrations at ground level.³⁸ Carbon monoxide (CO), a colorless, odorless gas, primarily results from incomplete combustion of carbon-containing fuels. It hinders the blood’s ability to carry oxygen and can be especially hazardous in enclosed