Coronavirus | Aerosols can travel up to 10m; ventilation is the key, says government

Ventilation is a community defence that protects all, it points out

Aerosols could be carried in the air for up to 10 metres and improving the ventilation of indoor spaces would reduce transmission, a government advisory on stopping the spread of COVID-19 said on Thursday.

The advisory, issued by the Office of the Principal Scientific Adviser to the Government of India, said there was need to remember the simple measures that could reduce the transmission of SARS-CoV-2.

“Ventilation can decrease 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. Ventilation is a community defense that protects all of us at home or at work,” it stated.

It recommended adding outdoor air in offices, homes and public spaces. Droplets and aerosols were the key transmission modes of the virus. While droplets fell up to 2 metres from an infected person, aerosols could travel up to 10 metres.

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Ventilation in hutments

Ventilation in hutments could be improved by adding “jaali or other simple air outlet”, apart from installing exhaust fans. “It is advised that jaali/air outlets with exhaust fans are installed by gram panchayats in homes where there is no cross-ventilation,” the advisory said.

For workplaces, it recommended keeping doors and windows open while air-conditioners were on. Hospitals should ensure that vaccinations were carried out in well-ventilated areas and public transport like buses should keep windows open and use exhaust fans.

For rural or semi-urban areas, the advisory said every person entering the area should undergo a Rapid Antigen Test before entry for which ASHA and Anganwadi workers should be trained and protected. These workers should be given N95 masks even if they are vaccinated, it added.