Aerosols can travel up to 10 metres, says Centre’s new Covid-19 advisory

Cautioning people to maintain social distancing to prevent the transmission of the Covid-19 virus, the office of the Principal Scientific Adviser to the Government of India on Thursday said that aerosols, one of the key transmission mode of the SARS-CoV-2, can travel in the air up to 10 meters.

While sharing a set of guidelines called “Stop the Transmission, Crush the Pandemic”, the panel said, “Always Remember: People who show no symptoms can also spread the virus.” While stating that proper ventilation can prevent the spread of the virus, the panel added, “Running air conditioners while keeping windows and doors shut, traps infected air inside the room, and increases risk of transmission from an infected carrier to others.”

The advisory also recommended the use of gable fan systems and roof ventilators in offices, auditoriums, shopping malls and other closed public spaces. “Frequent cleaning and replacement of filters is highly recommended,” it said.

Explaining about aerosol and droplet transmission, the advisory stated that saliva and nasal discharges in the form of droplets and aerosols by an infected person is the primary mode of virus transmissions.

Speaking on how the virus is transmitted via surfaces, the advisory read: “Droplets emitted by an infected person land on various surfaces (where they can survive for a long time). As such, frequent cleaning of high contact points such as door handles, light switches, tables, chairs and the floor with disinfectants like bleach and phenyl is recommended.”

The document also highlighted the importance of well-ventilated spaces in diluting the risk of transmission from one infected person to the other. “Just as smells can be diluted from the air through opening windows and doors and using exhaust systems, ventilating spaces with improved directional air flow decreases the accumulated viral land in the air, reducing the risk of transmission,” it added.

Listing out measures that the government can take to contain and combat the virus, the guidelines stated that community-level testing and isolation have to be ramped up in rural and semi-urban areas. “Rapid antigen tests must be done for people entering the area. The health workers conducting the tests must be give N95 masks. Also, oximeters should be provided to monitor the infected persons,” the advisory stated.