The office of the central government’s principal scientific adviser, K VijayRaghavan, on Thursday released a fresh set of guidelines on how to check the transmission of the coronavirus. It said that aerosol particles “can be carried in the air up to 10 metres”.

Apart from physical distancing and the use of masks, the advisory highlighted how better ventilation can decrease the risk of transmission of the infection.

“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 load in the air, reducing the risk of transmission,” the advisory, titled “Stop the Transmission, Crush the Pandemic”, said.

The Centre’s advisory added that ventilation was a “community defense” that protected everyone from the infection at work and home.

“Introducing outdoor air in offices, homes and larger public spaces is advised,” it added. “Measures to improve ventilation in these spaces must be taken up on urgent priority in urban and rural areas alike, recommendations for hutments, homes, offices and large centralised buildings are given.”

The guidelines stated that simple strategic placement of fans, open windows, including slightly open ones, and doors can let in fresh air and improve the air quality inside.

“Introduction of cross ventilation and exhaust fans will be beneficial in curtailing the spread of the disease,” the advisory added.

For buildings with central air-management systems, improving central air filtration is especially helpful when enhanced outdoor air delivery options were limited, the advisory said.

“In offices, auditoriums, shopping malls etc use of gable fan systems [or exhaust fans] and roof ventilators are recommended,” it added. “Frequent cleaning and replacement of filters is highly recommended.”

Here are the ways to curb aerosol and surface transmission

The guidelines said that saliva and nasal discharge in the form of droplets and aerosols by an infected person are the primary modes of virus transmission. “Infected person who shows no symptoms also transmit[s] the virus,” they said. “People without symptoms can spread the virus. People should continue wearing a mask, wear double masks or a N95 mask.”

The advisory added that droplets emitted by an infected person can land on surfaces and survive there for a long time.

“When someone touches these contaminated surfaces, and, without washing hands with soap, touches their mouth, nose or eyes, they can contract the virus,” it said.

The guidelines said that frequently cleaning high-contact points such as door handles, light switches, tables, chairs and the floor with disinfectants can remove the virus from surfaces.

India has been tackling the second wave of the coronavirus. On Thursday, it recorded 2,76,110 new cases, taking the total count of infections to 2,57,72,440 since the pandemic broke out in January 2020. The country’s toll rose to 2,87,122 as it registered 3,874 deaths in the last day.

The country now has 31,29,878 active cases, while 2,23,55,440 patients have recovered from the infection.

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