Is there a link between Covid and air pollution? What experts say

The world is in the third year of the pandemic – what has been defined as a "once-in-a-century" health crisis – but fears over the mutation of the virus and new variants is not yet over.

Globally, more than 52 crore cases and over 62 lakh deaths have been reported so far, according to the WHO tally, since the first patient was registered in China's Wuhan city in November 2019.

Regionwise, Europe has seen the highest number of overall cases with over 22 crore infections. But country wise, the United States is on the top of the list with over 8.47 crore cases logged overall. While restrictions have come and gone, and come back, across nations to check the spread of the virus, experts have looked at other factors too that affect Covid patients in various researches.

A study by a team of German researchers has delved deeper into the effects of air pollution on Covid patients and morbidity linked to the air pollutants. "Our results indicate that long-term NO2 exposure may have increased the susceptibility for Covid-19 morbidity in Germany. The results demonstrate the need to reduce ambient air pollution to improve public health," says the team led by Susanne Koch, of Universitätsmedizin Berlin, a large teaching hospital. "Long-term exposure to air pollutants as nitrogen dioxide (NO2), nitrogen monoxide (NO), ozone (O3), and particulate matter (<10µm PM10), < 2.5µm PM2.5,) has a negative impact on respiratory functions," it highlights.

Many of those infected needed intensive care due to exposure to air pollution, the researchers found. "After adjustment for risk factors in the tri-pollutant model (NO2), O3, PM2.5) an increase of 1µg/m³ NO2 was associated with an increase of the need for intensive care due to Covid-19 by 4.2 per cent (95% CI 1.011–1.074), and mechanical ventilation by 4.6 per cent (95% CI 1.010–1.084). A tendency towards an association of NO2 with Covid-19 incidence was indicated, as the results were just outside of the defined statistical significance (+1.6% (95% CI 1.000 -1.032)). Long-term annual mean NO2 level ranged from 4.6µg/m³ to 32µg/m," the study underscores.

Earlier, a Harvard T.H. Chan School of Public Health study led by Xiao Wu and Rachel Nethery and senior author Francesca Dominici had found an association between air pollution over many years with an 11 per cent increase in mortality from Covid-19 infection for every 1 microgram/cubic meter increase in air pollution. Many Americans, the experts highlighted, breathe air with 8 micrograms/cubic meter of particulate matter.