New Delhi: With the national capital recording the season’s worst Air Quality Index (AQI) Tuesday, concerns about the impact of rising pollution and dipping temperatures on the coronavirus pandemic are persistently increasing.
Several studies, conducted over the course of the pandemic, have pointed out that Covid-19 deaths occur due to long-term exposure to ‘urban air pollution’.
ThePrint spoke to several doctors and experts, who said that rising pollution will possibly lead to an increase in coronavirus cases as respiratory infections are at the heart of Covid-19.
Doctors said that while they are expecting testing numbers to increase as more people get pre-emptive Covid-19 tests done, the focus should be on appropriate Covid-19 behaviour.
As of Wednesday, Delhi recorded a total of 3,14,224 cases with 5,854 deaths and 2,86,880 recoveries.
Delhi’s rising pollution
According to the Central Pollution Control Board (CPCB), Delhi’s air quality plummeted to the “very poor” category Tuesday, with the AQI being 304. This happened for the first time this season.
In the preceding days, the AQI average remained in the “poor” category. The AQI on Monday was at 261, while on Sunday it was at 216 and 221 on Saturday.
On Wednesday, the AQI returned to the “poor” category at 279.
Environmentalists said that while the Delhi government has come up with plans to combat pollution, a comprehensive blueprint is necessary.
“At this time of the year hospital admissions and respiratory illnesses anyway increase due to the rising pollution levels,” said Anumita Roy Chowdhury, executive director, Centre for Science and Environment.
“This year we have the double burden of Covid with pollution. Delhi residents’ lungs are compromised due to prolonged exposure to pollution, which is worrisome,” she added.
‘Urban pollution and severe Covid outcomes’
Concerns also stem from various studies that have been conducted during the pandemic linking pollution exposure to critical Covid-19 outcomes.
A study by Emory University published in the journal Innovation in September said, “Long term exposure to urban air pollutants, especially NO2, may enhance population susceptibility to severe Covid-19 death outcomes.”
The same study also found that “reduction in urban air pollution exposures would have avoided over 14,000 deaths among those who tested positive for the virus as of July 17, 2020”.
Another study by Harvard University in April found that “an increase of only 1 μg/m3 in PM2.5 is associated with an 8 per cent increase in the Covid-19 death rate”.
Closer home, a study in Delhi conducted by the Radiology Department at Indraprastha Apollo Hospital found that years of exposure to bad air has caused structural changes to lungs of Delhi-NCR residents, making them more susceptible to respiratory illnesses than residents in Bengal, Bihar or Odisha.
‘Expect Covid cases to spike’
Doctors and experts said that with the rising pollution levels and onset of winter, Covid-19 cases are expected to rise.
“We are expecting a rise in cases as this is the ideal time for virus incubation. Immunity is also compromised due to pollution levels,” said Dr B.L. Sherwal, director at the Delhi government-run Rajiv Gandhi Super Speciality Hospital.
“The concern is that as people go out for walks, especially the elderly, their immunity is compromised due to pollution and they become easily susceptible to Covid.”
Doctors also said that those with underlying respiratory illnesses are even worse off during this time.
“In mild Covid cases, lungs are not compromised. However in the 10-15 per cent cases that turn severe, breathlessness further increases with pollution which can turn fatal,” said Dr S. Chatterjee, internal medicine specialist at Indraprastha Apollo Hospital.
‘Testing numbers to increase’
Doctors are also expecting to see a rise in testing numbers.
“The main symptoms of both Covid, as well as pollution-induced respiratory illnesses, are similar like sore throat, cough and cold; testing is expected to increase whenever these symptoms occur,” said Dr Chatterjee.
Doctors added that testing would increase along with awareness among the public about Covid-19 symptoms.
“People’s awareness is reflected in Delhi’s rising testing numbers. Delhi is conducting 50-60,000 tests a day because people are aware and are getting themselves tested in time if they feel any symptoms,” said Dr Sherwal.
Experts, however, denied that any change in the testing policy is required to keep up with rising pre-emptive testing.
“Air pollution is also closely related to respiratory infection caused by other microorganisms,” said Dr Giridhar Babu, Professor and Head, Lifecourse Epidemiology at Public Health Foundation of India.
“The net results is that the health system might test more suspecting Covid. As long as it is a syndromic approach which is used for testing, it is fine. No need to change test policy as GoI-ICMR has already introduced on demand testing in the latest guidelines,” he added.