The Role of Global Air Pollution in Aging and Disease

Reading Smoke Signals

Caleb E. Finch

• Publisher: Academic Press
• Year: 2018
• Print ISBN: 9780128131022
• eBook ISBN: 9780128131039
• Topic: Medicine
• Subtopic: Geriatrics

Global Air Pollution in Aging: Reading Smoke Signals is a complete reference connecting environmental pollution research to the human aging process. Since 1800, lifespans have more than doubled as infections declined and medicine improved. But the 20th century introduced a new global scourge of air pollution from fossil fuels with the potential to damage arteries, hearts and lungs that has been related to chronic exposure of air pollution from fossil fuels. Risk areas of study include childhood obesity, brain damage associated with air pollution, increased risk for autism in children and dementia in older adults.In humans and animals, air pollution stimulates chronic inflammation in different organs, and genetic vulnerability to air pollution is being recognized, particularly for carriers of the Alzheimer risk gene ApoE4.- Connects environmental pollution research to the human aging process- Raises new issues relevant to the controversies on air pollution and global warming, challenging assumptions that lifespan will continue to increase in the 21st Century- Examines the burden of air pollution to disadvantaged populations, with anticipated greater impact in developing countries which rely on fossil fuels for economic development in future decades

Chapter 1

The Three Smokes in Global Mortality

Abstract

Airborne toxins cause 14 million premature deaths worldwide according to the World Health Organization. Most of these toxins arise from fossil fuels, cigarettes, and inefficient home fires that I designate as “the three smokes.” Their microscopic particles share toxic properties that exacerbate oxidative stress and inflammation and accelerate many aging processes. Dust from the earth's crust can also be toxic. Air pollution particles are characterized by size, with standards set for particles smaller than 2.5 μm (PM2.5). The particles and gases that comprise air pollution are also included in the exposome, a global environmental assemblage of toxin exposure, starting at conception and extending across the life span. Some individuals or groups may be resistant to airborne toxins, as shown for elderly surviving cigarette smokers. The growing exposure to toxins from fossil fuels and tobacco since 1800 was concurrent with longevity increases. In essence, we have swapped mortality caused by infections for accelerated aging from fossil fuels and cigarettes. The toxic mechanisms in airborne particles are considered in the next chapters.

Keywords

Ambient air pollution; Biomass burning; Cigarette smoke; Dust; Exposome fossil fuels; Household air pollution; Longevity; Mortality rates; PM10; PM2.5; Toxicity

Chapter Outline

1. 1.1 Overview
2. 1.2 Airborne Toxins, a Primer
3. 1.3 Caveats From Cigarettes
4. 1.4 The Three Smokes and Mortality
   1. 1.4.1 Ambient Air Pollution
   2. 1.4.2 Cigarettes
   3. 1.4.3 Biomass Smoke, Inside and Out
   4. 1.4.4 Plus Dust
5. 1.5 Interactions of the Three Smokes
6. 1.6 The History of Air Pollution During Expanding Longevity
7. 1.7 Conclusions
8. References

1.1. Overview

Environmental gerontology is upon us: Because of the low heritability of life span (Preface), we must look to lifestyle and environment as the strongest determinants of the life span. Not only do individual outcomes of aging depend on lifestyle choices of diet and exercise, but also individuals have different exposure to ubiquitous airborne toxins that have major roles in aging.

The World Health Organization (WHO) now recognizes that air pollution promotes many diseases of aging and kills prematurely. Globally, 15 million adults per year die from noncommunicable diseases attributable to airborne toxins (Table 1.1), mainly heart attacks and strokes, cancer, and chronic obstructive pulmonary disease (COPD). Moreover, airborne toxins from fossil fuels and cigarettes are linked to metabolic dysregulation and dementia (Chapter 3, Table 3.1). Even worse, air pollution impacts our pre- and postnatal development with manifold consequences throughout life (Chapter 4). Exposure during development impacts brain myelination and also increases obesity, a risk factor in heart disease and dementia. The “smoke” from fossil fuels joins that from cigarettes, causing most of the premature, or avoidable, mortality.

Table 1.1

Mortality From Airborne Toxins

	Annual Excess Mortality, Millions
Ambient air pollution	4.2 (Cohen et al., 2017)
Household air pollution	4.3 (WHO Indoor AP, 2017)
Cigarette smoke:
Direct	6.4 (GBD Tobacco Collaborators, 2017)
Second hand	0.65
Total from airborne toxins of human origin	15.15 million

Mortality from noncommunicable disease is 38 million/year. Also see Lelieveld et al. (2015) and Landrigan et al. (2017).

In addition, nearly 3 billion breathe also noxious household third-hand smoke from “biomass” fuels such as wood or dried dung (WHO Indoor Air Pollution, 2017). Thus, we must consider airborne toxins from the three smokes: biomass, fossil fuels, and cigarettes. I propose that the airborne toxins from ambient air pollution (AAP), cigarette smoke (CS), and household air pollution (HAP) be considered as gerogens, or agents that accelerate aging processes. Airborne toxins from fossil fuels and cigarettes induce oxidative stress and inflammatory responses shared with many aging processes.

My synthesis of this huge literature will emphasize findings from studies of large population samples and experimental studies with laboratory animals and cultured cells. Combustion of fossil fuels, biomass, and tobacco yields particles and vapors that penetrate deep into our lungs, with broader impact than that was initially understood for tobacco carcinogens. The three smokes cause oxidative stress and induce genes for detoxification and inflammatory pathways throughout the body (Chapter 2). These toxic effects of fossil fuels, biomass, and tobacco are convergent: as organic materials, their shared components are ultimately derived from the combustion and degradation of organic residues of animals, plants, and microbes. Their main initial impact is in the respiratory tract, followed by indirect responses throughout the body that even cross the placenta to alter brain development. Ultimately, we will understand their interactions with aging as outcomes of selective gene regulation with influences of genetic variants.

Your author is a human biologist with an active “wet-lab” program on the neurobiology of aging. Our focus reflects collaborations with demographers, epidemiologists, and field anthropologists. I am keenly aware that correlation does not prove causality. Individual variation and subgr...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Dedication
• Preface
• Acknowledgments
• Chapter 1. The Three Smokes in Global Mortality
• Chapter 2. The Toxic Nature of the Three Smokes
• Chapter 3. Air Pollution in Diseases of Aging
• Chapter 4. Air Pollution and Cigarettes Cloud Development
• Chapter 5. Air Pollution in Our Future Longevity
• Glossary
• Subject Index