Is it safe to travel in plane amid coronavirus crisis?
New Delhi : Most of the domestic air travel has been relaxed in India. After staying away from the skies for more than two months, the companies are eagerly trying to resume services like older time. Currently, limited flights have been put in place which are mainly ferrying stranded people across the country.
In less than a week, at least five cases of passengers who travelled in the flight have been found coronavirus positive. They all have been quarantined and are being treated as per measures announced by the government, but this has raised serious questions on how safe is it to travel by plane during such crisis?
There are different rules which have been set for the passengers taking the domestic flight. Some states have asked them to go under home quarantine for a minimum time of one week. This has been seen on the global level too.
On June 8, the UK announced that it is mandatory for passengers to isolate themselves for two weeks after arriving in the country. Cut to India, situation is no different as there is a lot of confusion over the new guidelines to ensure safety of the passengers.
Let's talk about the spread of coronavirus inside an aircraft. Since the coronavirus is still new, not much has been known about its properties and how it spreads.
Based on the available information, US Centers for Disease Control and Prevention generally tries to track down people sitting in the two rows in front and the two rows behind passengers found to have serious infections.
A 2018 study by researchers from Emory University in Atlanta attempted to model how passengers and crew moved about an aircraft, and how that might affect the transmission of infectious diseases.
"A droplet-mediated respiratory infectious disease is unlikely to be directly transmitted beyond one metre from the infectious passenger. Thus, transmission is limited to one row in front of or in back of an infectious passenger," the researchers concluded.
But, in the case of coronavirus it has been seen that passengers at a distant seat have also been infected. Now, this may have happened in two situations – either the two had come in close contact or the infected person may have touched the contaminated surface either in the plane or airport itself.
It has also been mentioned that because cabin crew moved around the aircraft and had numerous contacts with different passengers, they could generate several new infections, and concluded "it is imperative that flight attendants not fly when they are ill".
Meanwhile, a researcher has claimed that the virus cannot travel via air inside the airplane. Jean-Brice Dumont argues that the way modern aircraft are designed means that the air is intrinsically very clean. "Every two to three minutes, mathematically, all the air is renewed," he says. "That means 20 to 30 times per hour, the air around you is completely renewed."
The recycled air, which is reused in part to keep temperature and humidity at the correct levels, is passed through HEPA (high-efficiency particulate air) filters that are similar to those used in hospitals. The Covid-19 virus is about 125 nanometres in diameter (a nanometre is a billionth of a metre) and is within the particle-size range that HEPA filters capture - 10 nanometres and above.
Also the air flow inside the cabin is vertical from top to bottom so it is certainly not possible for virus to travel among rows.
"The air flows vertically. It is blown from above your head and evacuated from beneath your feet. That makes the level of propagation of anything in the air quite limited. So a passenger from row one, for example, cannot contaminate someone in row 20."
Though there are still many factors which need to be discussed on air transmission and air filtration. It is advised that passengers wearing masks and using elbow during coughing and sneezing will help in reducing the transmission risk.