Scientists probe link between Covid-19 and deadly air pollution

by CCAC secretariat - 6 August, 2020
Air pollution may be putting people further at risk during a global pandemic. The link is spurring calls to improve air quality as part of the post-Covid recovery.

In the early weeks of the global Covid-19 pandemic, people desperate for good news received a thin silver lining: the Himalayas were visible again, spanning the northern Indian horizon for what may have been the first time in 30 years. As cities around the world ground to a halt in March and April to slow the rapidly spreading virus, many urban residents got a breather from air pollution. Kenyans reported seeing the jagged peaks of Mount Kenya from behind Nairobi’s skyscrapers and NASA satellite data showed a drop in pollution over the highways spanning the United States’ northeast corridor.

“This is a stark confirmation of the contribution of our everyday activities to sources of emissions of the air pollutants that we breathe and the greenhouse gases that drive global warming,” wrote the Scientific Advisory Panel of the Climate and Clean Air Coalition (CCAC) and Invited Experts in May. “The speed with which emissions have fallen shows how quickly we can improve our environment when motivated and how vulnerable we are living in degraded environments.”

These vulnerabilities already include around 7 million people who die prematurely every year from air pollution. As scientists around the world scramble to understand the coronavirus that is ravaging the globe, research shows that there may be one more way that air pollution is putting people at risk. Those living in areas with higher levels of air pollution face a greater risk of infection and experience more severe Covid-19 symptoms and outcomes. The pandemic has exposed the perils of acting in isolation against the greatest global threats but it has also highlighted the potential for decisive action to produce sweeping positive change. Applying these lessons not just to Covid-19 but to the related threats of climate and air pollution will be a powerful tool.

In one study that has yet to be peer reviewed, researchers at the Harvard University T.H. Chan School of Public Health found that higher levels of fine particulate matter, or PM2.5, are associated with higher death rates from Covid-19.

“The study results underscore the importance of continuing to enforce existing air pollution regulations to protect human health both during and after the Covid-19 crisis,” wrote the authors.

Researchers even said that if particle levels averaged a single unit lower for the past 20 years in New York City, the worst-affected city in the United States, then 248 less people would have died in the weeks preceding the early April study.

“If you’re getting Covid, and you have been breathing polluted air, it’s really putting gasoline on a fire,” said Francesca Dominici, a Harvard biostatistics professor and the study’s senior author to National Geographic.

On June 11, the World Bank hosted a webinar discussing the ongoing research and what still requires further study.

Bo Pieter Johannes Andrée discussed his working paper for the World Bank which investigates the relationship between PM2.5 and Covid-19 in the Netherlands with striking findings. Expected Covid-19 cases increase by almost 100 percent when pollution concentration increases by 20 percent. 

Another paper examining coronavirus deaths in 66 administrative regions in Italy, Spain, France and Germany found that 78 percent of fatalities occurred in the five regions with the highest concentration of nitrogen oxide (an air pollutant) combined with air flows that prevented the dispersion of air pollution. 

“I think it would be surprising if we didn’t see a link between air pollution and Covid-19 given what else we know about air pollution and Covid-19. We already know air pollution is associated with the risk of chronic disease and mortality,” said Anna Hansell, a Professor of Environmental Epidemiology at the University of Leicester during the webinar. “But I think there’s various gaps we need to fill in to understand this better.”

There is already research on how PM2.5 increases infection risk from other airborne viruses. A 2003 study, for example, found that patients with Severe acute respiratory syndrome (SARS) living  in areas with high air pollution were twice as likely to die as those from regions with low air pollution.

Air pollution is, in fact, the deadliest environmental health risk humans face, cutting short 7 million lives every year— that’s one in eight premature deaths. In large part, it is because those exposed to high levels of pollutants (which includes a staggering 9 in 10 people in the world) can experience increased mortality from things like stroke, heart disease, lung disease, and cancer.

The poorest suffer

Scientists are racing to better understand what exactly this could mean for the pandemic.

“It’s a correlation and you need to look beyond that to see what else is going on. These areas with high pollution levels also tend to be areas with high population density, they tend to be well-connected areas,” said Hansell. “They also may have areas of deprivation and that in itself is a risk factor.”

There is a strong link between poor communities and high levels of air pollution. Given that poor people are less likely to have access to preventative medicine and more likely to have chronic diseases, they may be otherwise predisposed to developing severe Covid-19 infections.

If a link is established, it could be an important way to target funding and resources to high-risk communities.

“This work will be very useful in the near term. Cities in many developing countries are really trying to prioritize how and where to allocate medical and civil resources to save lives,” said Somik V. Lall, the World Bank’s global lead for territorial and spatial development, in the webinar.

As researchers continue to shore up findings there is already ample evidence that prioritizing air pollution can save lives. These efforts also have a climate benefit. Black carbon, a component of PM2.5 air pollution, is also a short-lived climate pollutant 460-1,500 times stronger than carbon dioxide (per unit of mass) at warming our atmosphere. Unlike carbon dioxide, which remains in the atmosphere for centuries, black carbon dissipates in just days which means steps to reduce it  can be felt almost immediately, both in air quality and its impacts on the local climate. 

“You can think of it like a relay race, the short-lived climate pollutants sprint out there and keep us in the game while we’re trying to win the battle of zero carbon emissions by 2050. Speed is their hallmark,” said Durwood Zaelke, the President of the Institute for Governance & Sustainable Development in an interview with Green Tech Media. “We have our handle on very important levers to slow down climate change and I think the pandemic is showing us evidence that if we take action we get a fast response in the climate system, and that’s encouraging.”

These actions are well within reach, including simple and affordable interventions like the widespread use of clean cookstoves, eliminating high-emitting diesel vehicles, and banning open agricultural burning.

“This has always been the core message of the Climate and Clean Air Coalition. Many people in the world, some for the first time, are inadvertently experiencing what it is like to live with clean air; this benefit does not have to come at the expense of our security and economic future,” continues the CCAC Scientific Advisory Panel.


Building Back Better

If seized upon, this crisis could have a much bigger silver lining: creating the conditions to tackle what will be humanity’s greatest challenge this century, climate change. As we begin to recover from the fallout of the coronavirus pandemic, there is a chance to build back better.

Some 350 medical groups, representing over 40 million doctors, nurses and other health professionals from 90 countries (including many working on the frontlines of the pandemic) sent a letter in May to G20 leaders urging them to put climate and air pollution at the centre of their economic recovery packages.

“A truly healthy recovery will not allow pollution to continue to cloud the air we breathe and the water we drink. It will not permit unabated climate change and deforestation, potentially unleashing new health threats upon vulnerable populations,” the letter read. 

Public sentiment supports making improvements in air quality part of post-Covid recovery plans. A YouGov poll showed that at least two-thirds of citizens in Bulgaria, Great Britain, India, Nigeria and Poland support stricter laws and enforcement to tackle air pollution following the Covid-19 crisis. In Nigeria and India more than 90 percent of those surveyed wanted to see air quality improved in their area.

Inger Andersen, Executive Director of the United Nations Environment Programme, said actions like investing in clean transportation would mean better health and less pollution for the more than 90 percent of the world’s population that currently live in areas where air pollution exceeds safe levels.

“While Covid-19 is by no means a victory lap for environmentalists, it is also time for us to seize on those moments of cleaner air and make them a non-negotiable part of our future.” Ms Andersen said. 

In an opinion piece, former UN Secretary General, Ban Ki-moon said governments will never have a better chance to address these issues.

"Governments must seize these opportunities to put clean air and climate justice at the heart of recovery plans, in line with the 2015 Paris climate agreement," Ki-moon said. "This will not be easy, but it can and must be done. The pandemic has taken a heavy toll, but it could just be a taste of things to come. We owe it to ourselves and future generations to build back better."

Helena Molin Valdés, Head of the Climate and Clean Air Coalition Secretariat, said: “Any stimulus packages should be green and efforts to rebuild economies should include climate change and air pollution mitigation. The pandemic laid our interconnectivity bare, driving home the message that fighting a global crisis in isolation is a losing battle. If we can apply that lesson to climate change, we might have a shot at our greatest challenge yet.”