Pandemic highlights urgent global need to control pollution, doctors say

Harvard professor calls for more research into whether inequities in air quality ‘may be a cause of the stark disparities of the Covid-19 pandemic along racial and ethnic lines’, reports Andy Gregory

A man wearing a facemask crosses a street amid smoggy condition in New Delhi in October (Jewel Samad/AFP via Getty Images)

The coronavirus pandemic should be a “wake-up call” to tackle global air pollution and “end our tolerance” for dirty air in disadvantaged neighbourhoods, doctors have warned.

Suggesting that disproportionate levels of exposure to polluted air could be partly to blame for “severe disparities” in coronavirus death rates among ethnic minorities and low-income communities, physician researchers at Boston’s Beth Israel Deaconess Medical Centre (BIDMC) said Covid-19 had “highlighted the widespread health consequences” of air pollution.

In an article published in the Annals of the American Thoracic Society journal, researchers from the Harvard Medical School-affiliated teaching hospital reviewed studies suggesting a significant link between Covid-19 mortality and air pollution exists – with one study blaming long-term exposure to polluted air for 15 per cent of global coronavirus deaths.

In the study cited, this figure is calculated to rise to 17 per cent in North America, 19 per cent in Europe and 27 per cent in East Asia – with more than half of the man-made pollution deemed responsible thought to stem from fossil fuel usage.

These recent studies “add convincingly to a large body of evidence showing that exposure to air pollution exacerbates viral respiratory infections and consequently widens health disparities”, the researchers wrote.

Before the pandemic, it was estimated that 91 per cent of the world’s population lived in areas where air pollution levels exceeded the World Health Organisation’s air quality guidelines.

In addition to causing chronic lung and cardiovascular conditions, the authors note that exposure to common air pollutants has also been found to impair our immune response and lead to both increased susceptibility to viruses and more severe viral infections.

More specifically in relation to Covid-19, they cited research suggesting that daily exposure to pollutants could increase transmission by interfering with ACE2 receptor proteins in our bodies, through which the virus enters. They also referenced speculation that, by acting as a platform for viral coronavirus aerosols, pollution particles could allow them to remain suspended in the air for longer than droplets, potentially infecting more people.

Noting that the pandemic has “disproportionately affected racial/ethnic minorities and low-income communities who have suffered higher rates of hospitalisations and mortality”, the authors suggested that air pollution “may contribute to these severe disparities”.

In the US, racial minorities on average are more exposed to two of the most common air pollutants than white people, they wrote, highlighting a study which found that, in Massachusetts at least, this inequality had worsened in recent years despite overall air quality improving.

“Racial minorities are more likely to live in areas closer to industrial pollution and to work in business sectors with higher exposure to pollution,” they said.

“These inequalities in residential and occupational air pollution exposure may be a cause of the stark disparities of the Covid-19 pandemic along racial and ethnic lines.”

Senior author Mary Rice, a physician at BIDMC and assistant professor at Harvard Medical School, called for research to establish whether air pollution plays a role in these disparities.

With an Imperial College London study in 2015 also suggesting that deprived communities and ethnic minorities were the worst-affected by air pollution in England, the Labour Party’s shadow environment secretary Luke Pollard, called on the government in September to “urgently review the combined impact of air pollution and Covid on black, Asian and minority ethnic communities who live in some of the worst polluted areas in England”.

Researchers at the Office for National Statistics had a month earlier failed to find a conclusive link, but said nevertheless that air pollution could be a contributing factor to this inequity, adding that more exhaustive research would likely be needed to determine whether this was the case.

According to the paper published this week, this apparently potent mixture of air pollution and Covid-19 comes despite cross-continental studies finding that levels of some of the most toxic and widespread air pollutants – particulate matter from fossil fuels and nitrogen dioxide – have often fallen as a result of restrictions to slow the virus’s spread.

While the true impact of these – likely short-lived – falls in pollution levels may never become clear, the researchers said that they “may have softened the blow from Covid-19” by reducing deaths from other non-infectious diseases.

They pointed to studies suggesting reductions in the level of one particularly potent type of particulate matter averted 24,000 premature deaths in China and 2,100 in Europe – with reductions in nitrogen dioxide also thought to have saved thousands lives.

Noting that the pandemic “has provided a glimpse into the health benefits of cleaner air”, the authors concluded: “As we emerge from this devastating public health crisis, Covid-19 is a wake-up call for the need to adopt stricter air quality standards and end our tolerance for pollution in disadvantaged neighbourhoods.

“As part of our post-Covid-19 recovery, we must clean up the air to improve respiratory health and equality worldwide.”