Link between Air Pollution and COVID-19

Context: Sudden spike of Covid Cases in National Capital linked to Air Pollution.

Background: Delhi has reported over 6,000 new Covid cases every day since November 3 and 13 per cent of this may be linked to increased air pollution, stated by the Indian Medical Association.

The IMA advised people not to venture outdoors early morning, when pollution levels are at their highest and senior citizens and children believed at greater risk of infection by the coronavirus, are more likely to develop infections and allergies.

Pollution in New Delhi had almost disappeared earlier this year, when the government imposed a nationwide lockdown to stop the coronavirus. But the curbs have been lifted and the pollution, and the virus, are back with a vengeance.

Delhi's overall air quality index (AQI), which includes the concentration of PM2.5 particles as well as bigger pollutants, has stayed above 400, on a scale of 500, for five consecutive days, government data showed.

The tiny PM2.5 particles can cause cardiovascular and respiratory diseases including lung cancer, and pose a particular risk for people with COVID 19.

In Detail

In the 7^th November's morning the national capital recorded an average AQI of 443, that reflects a rating of 401 or above is an indicator of "severe" pollution.

Patients who are sensitive to respiratory diseases may find it difficult to breathe if air quality levels (AQI) is between 50 and 100. An AQI of 300 makes it difficult even those who are otherwise healthy.

Medial experts have, for several weeks now, been harping on the link between air pollution and Covid infections and warned that unless air quality levels in Delhi and other major cities and regions of the country are brought under control, the COVID-19 virus is likely to spread further.

Recently conducted a study by six researchers from different European institutes concluded that 17 per cent of India's 1.26 lakh Covid-related deaths could be linked to exposure to air pollution. The global average for this statistic is 15 per cent.

COVID-19 and Air Pollution

There have been studies between April and November this year in both, developing and developed countries that have tried to find the relationship between COVID-19 and air pollution.

One study, states that Air pollution aggravating COVID-19 lethality based upon statistical models conducted across nine Asian cities, Delhi, Nagpur, Kanpur, Islamabad, Lahore, Jakarta, Tianjin, Guilin and Hebei, correlated particulate matter (PM) and its ability to transport the coronavirus aerosols (in air) into the respiratory tract of the humans and transmitting infections.

The study, published by Springer, concluded that air pollution was acting as a hidden element in intensifying the impact of COVID-19.

Similarly, a study conducted in Italy, Role of the chronic air pollution levels in the Covid-19 outbreak risk in Italy, found that air pollutants were very much likely to increase COVID-19 transmission in highly polluted places.

It found traces of SARS-CoV-2 RNA, the genetic material of the coronavirus on air pollutants. It was published in ScienceDirect. It also concluded that COVID-19 deaths could increase due to long-term exposure to PM.

Two studies in the United States prove that air pollutants like nitrogen dioxide (NO₂) and PM 2.5 were likely to enhance populations’ susceptibility to severe COVID-19 death outcomes.

A recent study published in the journal Science Advances found that long-term exposure to an additional one microgram per cubic metre of fine particulate matter was associated with an 11 per cent increase in death rates from COVID-19.

Air pollution is also an ally for COVID-19 in another way. Long-term exposure to air pollution has an effect on the respiratory system including lungs.

People with comorbidities are the most vulnerable, with risks to their lungs and heart because of air pollution. If COVID also causes inflammation, this leads to much more severe illness in these individuals.

When both, long-term exposure to air pollution and infection with the novel coronavirus occur together, there is an additive adverse effect on health, particularly with respect to the heart and blood vessels. This leads to greater vulnerability and less resilience to COVID-19.

Opposite View

Some scholars however, argue that an ecological study cannot be regarded as epidemiology due to ecological bias (i.e. lack of individual-level data), therefore it is unable to establish a cause-and-effect relationship. There are also multiple factors involved that may affect the results, for example, the temporal difference of the virus outbreak among the individual county, and the intervention time of the county to adopt physical distancing policies.

Air Pollution Facilitate the Viral Spread of COVID-19

It is believed that the main route of transmission of the virus is through human respiratory droplets and direct contact. Yet, it has also been hypothesised that the COVID-19 virus can be transmitted by particulate matter (PM) and aerosols.

A preliminary experimental analysis was conducted which identified the gene of COVID-19 in an ambient PM sample in Italy, and concluded that PM may potentially act as a transporter of the virus, although the virulence of COVID-19 remains unknown (i.e. vitality of the virus). Scientists also suggest that PM may serve as an early indicator of the epidemic recurrence by identifying the virus genome in PM.

Measures Need to be Taken

Besides maintaining hygiene, washing hands and maintaining social distancing, wearing masks is essential to reduce the risk of transmitting COVID-19.

Fossil fuel burning is one of the major anthropogenic sources of air pollution. A study modelled that emissions from fossil fuel combustion is one of the major causes of air pollution, which contributes to 65% of additional mortality due to the exposure. Given that renewable energy is cleaner than fossil fuel burning, a transition to renewable energy is essential to mitigate the climate crisis.

The NO₂ level also dropped dramatically after the lockdown (NO₂ irritates human airways and impairs immunity to lung infections). Another study estimated that the improved NO₂ levels from January to March due to the imposed lockdowns helped prevent more than 8,000 NO₂ -related deaths, 65% of which are due to cardiovascular disease and chronic obstructive pulmonary disease (COPD).

Conclusion

Public health in India, already in a bad state due to the novel coronavirus disease (COVID-19) pandemic, may worsen as winter takes hold of the northern part of the country, if global studies on the subject are to be believed.

The IMA has stressed that apart from immediate measures to protect oneself , long-term measures needed to be implemented to bring down air pollution levels.

The medical body acknowledged that the banning of firecrackers and stubble burning were "helpful public health measures" but urged people to adopt others, including the use of public transport, opting to buy energy-efficient vehicles, planting of trees and green cover, promoting recycling and making use of solar (or renewable) energy sources.

Connecting the Article

Question for Prelims : Consider the following statements

1. COVID-19 virus can be transmitted by particulate matter PM and aerosols.
2. COVID-19 virus can cause severe impact with PM and aerosols on the respiratory system.

Which of the statements given above is/are correct?

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Answer (c)

Question for Mains : Discuss the role of air pollution in facilitating COVID-19 virus. Suggest measures to be taken to meet these challenges.