Air pollution has long been recognized as one of the largest causes of non-accidental death in the world, and COVID-19 is highlighting just how deadly it is. As a virus that primarily attacks the respiratory system, COVID-19 has been taking advantage of lungs damaged by decades of breathing in contaminated air. Residents of urban neighborhoods—and in the U.S. particularly neighborhoods of color—have been breathing dirty air for decades. They now find themselves among the communities most vulnerable to the pandemic.
Across the world, people have been accustomed to live with a certain amount of air pollution, and in the U.S., air pollution has been on the rise since 2016. The kind of air pollution that is most connected to COVID-19 mortality rates is PM 2.5 pollution, of particles that are less than 2.5 μm in diameter. These are particles small enough to enter the respiratory system and the lungs, and large enough to carry toxins that can cause lung damage. This sort of pollution comes from car exhaust and power plants, as well as from burning wood and coal. In Philadelphia, where I live and work on air quality issues, some neighborhoods on the fence lines of the former South Philadelphia oil refinery have three times the national average of childhood asthma due to the concentration of pollutants like PM 2.5.
While this pollution can be mitigated through filtered masks, including the N95 mask that has been recommended as personal protective equipment (PPE) for health care workers fighting the coronavirus, these masks are only effective if worn properly and consistently. Surgical masks or cloth masks, while popular in many parts of the world like China, don't have the ability to filter out PM 2.5 particulate matter. And while staying inside can reduce the amount of PM 2.5 you breathe in, it does not prevent you from being exposed.
Long term damage from this kind of air pollution has made some particularly vulnerable to the current pandemic. Data about PM 2.5 and its impact on COVID-19 mortality rates first emerged out of Italy. Northern Italy, an early epicenter of the coronavirus, has some of the poorest air quality in Europe. Northern cities of Italy suffer from pollution from living in an area with little wind to disperse contaminants caused by automobiles, domestic heating, industrial, and agricultural sources. Shortly after the region became a hotspot, Italian researchers raised the possibility that the region's high mortality rate was, in part, due to its especially poor air.
More recently, researchers at Harvard looked at data from the United States and found this trend playing out across the nation: a greater proportion of people with COVID-19 are dying in U.S. counties with higher levels of PM 2.5 air pollution. These effects persisted after controlling for factors like household income, county population size, and smoking rates. Their results point to the same conclusion—long term exposure to high levels of PM 2.5 pollution results in increased vulnerability to COVID-19.
What Level of Death Is Normal?
With COVID-19, we are dramatically seeing some of the effects of air pollution on health. However, this is not the first time there has been such an impact. A study on the effects of the 2002 SARS epidemic in China found that SARS patients from regions with high air pollution were up to twice as likely to die from SARS compared with regions with lower pollution levels.
Ambient air pollution, in fact, has been identified time and again as one of the world's major health risks. Air pollution is thought to be responsible for between 7.11 to 10.41 million deaths a year, with higher mortality in areas like East Asia and Europe. It is long term exposure to air pollution that causes this increased mortality, which is due to conditions like cardiovascular and respiratory disease, lung cancer, and lower respiratory tract infections. A total halt on fossil fuel emissions, in fact, is estimated to be able to increase human life expectancy worldwide by over 1 year.
These health costs previously existed under the surface. Moreover, they remain concentrated in certain areas of the world. Globally, 21 of the world's 30 most polluted cities are all found in India, which has made experts alarmed at the impact the coronavirus could have in that country. In the United States, Black and Latinx populations are exposed to about 56 percent more PM 2.5 pollution than the national average. This is largely because Black and Latinx Americans tend to live in areas with higher levels of air pollution due to historic segregation and decisions of where to site dirty industries. For decades, environmental justice activists have decried the granting of permits for things like refineries, incinerators, and power plants in majority communities of color. For this and a number of other factors, life expectancy for communities of color is often lower than for white neighborhoods, even within the same city.
As time goes on, we are also getting a clearer idea that the coronavirus is more prominent and more lethal in Black communities across the United States. This, too, is likely for a number of reasons—employment, access to health care, reliance on public transit, and other inequalities certainly play a role. In Louisiana, Black residents account for 70 percent of all COVID-19 deaths, despite making up only 32 percent of the state's population. Louisiana is also home to one of the most highly polluted parts of the country, known as "cancer alley" for its concentration of petrochemical plants amidst the many majority-black communities between Baton Rouge and New Orleans.
Is There a Silver Lining?
In the midst of news that air quality is linked to the deadliness of the coronavirus, there have also been reports from around the world of cities with air cleaner than it has been in decades. Satellites are picking up on huge decreases in air pollution around large cities. Could this be a silver lining to the coronavirus crisis?
Only, I think, if there are measures put in place to make that clean air a common occurrence in our major cities. The kind of lung damage that puts one at risk of coronavirus complications comes from years and years of long term exposure. Unfortunately, the weeks of reduced emissions we are living through now are unlikely to have a long term impact, especially for people who have lived in heavily polluted communities for much of their lives.
In fact, the boldest changes in curbing air emissions in the U.S. have been federal legislation, notably the 1970 Clean Air Act, as well as the Obama administration's fuel economy standards that have pushed automobiles towards emitting less pollutants like PM 2.5. Since the start of the pandemic, the Trump administration has both granted a new, blanket loophole for violators of the Clean Air Act, and is replacing the Obama administration's fuel standards with a far less ambitious target. These policy changes are likely to be more significant in the long-run, and will make Americans, especially those living in heavily polluted areas, more susceptible to future pandemics like COVID-19.
Clear skies over cities like Los Angeles and New Delhi do provide an important reminder, however, that governments, businesses, and everyday citizens can take the kind of drastic action that makes substantive changes. And with the climate crisis likely to be even more significant for global mortality than the coronavirus crisis, there are reasons why there should be that kind of drastic action at a global scale.
With COVID-19, we have seen how quickly the world can change to rise to meet a sudden threat to global health. Now, it is up to future policy to see whether we can produce similar results to confront more slow-moving but more deadly crises of air pollution and climate change.