A Breath of Fresh Air

Choked: Life and Breath in the Age of Air Pollution, First Edition By Beth Gardiner Hardcover: 312 pages; $27.50 Chicago, IL: University of Chicago Press; First edition (April 19, 2019) ISBN-13: 978-0226495859

Writing about the health effects of air pollution for general audiences can be akin to steering between Scylla and Charybdis. Focusing too much on the numbers—four million deaths per year from ambient air pollution, seven million if including household air pollution¹—can seem dry and impersonal, but focusing too much on individual anecdotes can seem unscientific and not befitting the scale and scope of the problem. An emphasis on the adverse effects of air pollution seems overly gloomy and ignores the tremendous progress made in many cities and countries around the world, but an emphasis only on progress and potential does not give adequate weight to the population health toll.

Beth Gardiner’s book Choked: Life and Breath in the Age of Air Pollution skillfully navigates this terrain and provides a gripping and robust portrait of current air pollution conditions and their implications around the world. She captures the political, economic, and social factors that have led to this global challenge and that also provide some optimism regarding our ability to improve air quality globally. She directly tackles the contradictions inherent in an exposure that everyone experiences, but the implications of which few appreciate.

THE GLOBAL CONDITION

Gardiner tells the story of air pollution by deftly moving across settings that reinforce both the ubiquity of air pollution and the variability across cities and countries. An important element of Gardiner’s book is her recognition of populations most vulnerable to the health effects of air pollution, ranging from children working at brick kilns in India to agricultural workers in California to coal miners in Poland. But rather than portraying these populations as powerless and anonymous victims, Gardiner spends significant time talking to people to understand the circumstances that contributed to their exposures. More importantly, she devotes large sections of the book to conversations with community advocates and others who are working to effect change.

Although Gardiner’s observations in the field and conversations with individuals provide the backbone of the book, key aspects of air pollution science and epidemiology are discussed throughout. Her coverage of the state of the science is thorough and up-to-date, acknowledging the growing literature related to neurocognitive effects and birth outcomes rather than solely focusing on respiratory or cardiovascular effects. Few people outside of the scientific community connect air pollution with diseases like Alzheimer’s or Parkinson’s, and raising consciousness about these associations in an aging world is quite important.

There were two small omissions in the book, which do not detract from its power but represent missed opportunities in telling the comprehensive story of air pollution. The first was that, in spite of Gardiner’s emphasis on traffic and near-roadway air pollution, there was no discussion of ultrafine particulate matter. More generally, there was no discussion of how the scientific and regulatory communities have evolved in their thinking about the most relevant sizes of particulate matter. She does introduce the structure of the lung in the Prologue and makes reference to the size of fine particulate matter in Chapter 2, but does not go further and talk about the regulatory evolution from total suspended particles to PM₁₀ to PM_2.5 (particulate matter < 10 and 2.5 µg in aerodynamic diameter), nor does she consider the implications of not directly regulating ultrafine particulate matter given growing evidence of its health effects.² This does not detract from the scientific precision of the book, and may only be of interest to a narrow group of readers, but it would have made the story more vivid to describe what particles of different sizes do in the body and to contemplate the implications of an unregulated size fraction of particulate matter.

A second missed opportunity relates to indoor air pollution in the developed world. Gardiner rightly focuses on biomass burning and cookstoves in the developing world, which have a profound health impact that disproportionately affects low-income rural women and children, but it would have been an interesting contrast to examine residential exposures to air pollution in the developed world as well. Given that most people spend the vast majority of their time indoors,³ and given that residential exposures can often be addressed more readily than ambient air pollution, the indoor environment is an important part of the air pollution story in the developed world as well. There are also many interesting angles to explore, given strong socioeconomic exposure disparities,⁴ economic constraints that may preclude taking health-protective action, personal decisions made by households, and complex ethical questions such as whether smoking bans in public housing are morally justified.⁵

That said, a book about an exposure that influences everyone across the world must necessarily make hard choices about where to focus. Gardiner rightly hones in on the countries where the public health burden of air pollution is greatest (India and China), pinpoints the factors that have led to successes and failures in those settings, and draws lessons that can be extrapolated elsewhere.

CURRENT EVENTS

There are two topics that are difficult for a book on air pollution published in 2019 to avoid. The first is the antipathy of the Trump administration toward environmental protection and much of the environmental research enterprise.⁶ Gardiner acknowledges this reality but tackles it from a novel perspective by focusing one chapter on the players involved in drafting the 1970 Clean Air Act, telling a fascinating story that has details that will be unfamiliar to many inside and outside of the field. The bipartisan spirit and the focus on finding evidence-based common ground provide a stark contrast to present time.

In addition, as Gardiner indicates in the Epilogue and elsewhere, it is difficult to think about the effects of air pollution without considering climate change, particularly with wildfires occurring with alarming regularity and severity in California, Australia, and elsewhere. It is logical that Gardiner does not dwell on climate change, as the global implications of air pollution are sufficiently complex without weaving in climate change. But she does conclude by raising the important but often underemphasized point that strategies to address one will often address the other. Even more importantly, the near-term health benefits related to reduced air pollution may justify actions to mitigate climate change, given that the climate-related benefits have a much longer time horizon. This argument has been made many times in many settings, but it would have been interesting to get Gardiner’s take on the argument (or the perspective of the many individuals she interviewed).

A UNIVERSAL MESSAGE

Through her personal story as a parent living in London, her global observations and conversations, and her review of the scientific literature, Gardiner makes the issue of air pollution relatable to a range of audiences. For readers with little background in air pollution, Choked gives a primer about why it matters, who is at risk, and what we can do about it. For those well-versed in the scientific literature as well as the politics of air pollution, Choked educates about the personal experiences of those who are affected by air pollution and want to effect change in their communities, as well as some of the lesser-told stories connected to environmental regulation and pollution control. This makes Choked a valuable contribution to the popular literature on air pollution.