The Government of India on Thursday, 20 May, released new guidelines to stop the transmission of COVID-19 via aerosols and droplets, the key transmission mode of the SARS-CoV-2 that can travel through the air up to 10 metres.
The advisory from the office of the Principal Scientific Adviser stated that the droplets released by an infected person can land on various surfaces and that the virus can survive for a long time.
So, what are some of the effective ways to increase ventilation? Here’s what the guidelines say.
What does the advisory say about aerosols and droplets with regards to COVID transmission?
The advisory elaborated that aerosols and droplets are the key transmission modes of the coronavirus. While saliva droplets usually fall within two metres from the infected person, aerosols can be carried through the air up to 10 metres.
“Just as odour can be diluted in the air by opening windows and doors and using exhaust systems, ventilating spaces with improved directional airflow decreases the accumulated viral load in the air, reducing the risk of transmission,” the Office of Principal Scientific Adviser stated.
What does ventilation have to do with COVID-19 transmission?
According to the guidelines released by the government:
- COVID-19 transmission occurs through saliva and nasal discharge, and aerosol.
- In a closed, un-ventilated indoor space, droplets and aerosols become concentrated quickly and greatly increase the risk of transmission to others in the area.
- In outdoor areas, the virus particles get dispersed fast, and the dangerous concentration of the virus can be reduced by making sure that outside air flows in.
How can ensure my home is well ventilated?
- Keep doors and windows open.
- Fans should not be placed in a way that could cause contaminated air to flow directly onto someone else.
- Installing an exhaust fan is extremely important.
- You can also turn a pedestal fan to face outdoors to turn it into an exhaust fan. This creates the ideal flow of air for protection from indoor infection.
How can I improve ventilation in the workspace?
- Having the AC switched on and windows and doors shut traps infected air inside the room. This increases the risk of transmission.
- Even if the AC is on, keep your windows and doors ajar so that clean air can come in.
- Add a gable or exhaust fan for maximum air circulation.
My office has a centralised AC system. How can I ensure ventilation there?
- You can use roof ventilators and HEPA/regular filters for centralised AC systems in offices, malls, and auditoriums.
- The filters must be regularly cleaned and replaced.
- Make sure the filter fit is appropriate and that it is within the recommended service life.
What do the guidelines say about while using public transport?
- Ensure that windows and doors in buses and trains are opened to improve airflow.
- AC buses and trains must have an exhaust system.
How can ventilation be improved in hutments?
- Add a jaali (net) or any other simple air outlet to improve directional airflow.
- Install an exhaust fan next to the jaali or outlet.
- It is advised that gram panchayats should install these jaalis or other air outlets along with exhaust fans in homes that do not have cross ventilation.
A COVID positive person is isolated in my home. How can I improve ventilation for them?
- According to WHO, the infected individual should stay in a separate room. If this is not possible, other members of the house should keep at least one-metre distance from the patient.
- Choose a room with an air extractor or exhaust fan for the patient to isolate in, if possible.
- Open doors and windows on both sides of the room to increase cross ventilation.
- If possible, block the airflow from the infected person’s room towards the rest of the house.
- You may use a standalone air cleaner with a MERV14/F8 filter. However, this is not a replacement for ventilation.
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