More Covid-19 guidance needed for indoor spaces and ventilation, experts warn

Air particles can linger for several hours in poorly ventilated space.
More Covid-19 guidance needed for indoor spaces and ventilation, experts warn

Experts are warning that virus particles can linger in the air for several hours, but that recirculating air can help to minimise the risk of the virus spreading. File Picture: PA

Home and business owners need more public-health guidance on ventilation and air quality to help limit the spread of Covid-19, it has been warned.

Schools and other community facilities also need help in this area, John Wenger, professor of physical and environmental chemistry, University College Cork, and Orla Hegarty, assistant professor of architecture, University College Dublin, have warned.

They were speaking at an online seminar hosted by the Independent Scientific Advisory Group (ISAG). They explained how environmental factors, such as buildings, air quality, and ventilation, can impact on viral spread.

Aerosols containing Covid-19 can linger in the air from 30 minutes to several hours, depending on their size, Prof Wenger said, adding that aerosols can travel more than two metres and accumulate in poorly ventilated areas.

Schools, he said, were among the highest-risk environments and ISAG had advised the Department of Education to roll out air-monitoring. 

"There's no support, really, from the Department of Education," Prof Wenger said. "The advice given to teachers and principals is not good enough and the level of support has been poor as well."

Ms Hegarty said the built environment was a significant factor, pointing out that 66% of Covid-19 workplace outbreaks occurred in food-processing plants and that 50% of all Covid-19 deaths occurred in nursing homes.

"We need really specific, targeted, public-health information, so that people understand how this virus is being transmitted and then they can make smarter choices, like meeting outdoors, keeping a window open, wearing masks, or investing in filtration," Ms Hegarty said.

There was also some practical advice on how people can mingle safely indoors over the festive period.

"At home, people need to think about it like cigarette smoke and to think that it's not just about having a window open, it's about having air moving,” Ms Hegarty said.

"If you have the window in your kitchen cracked open, keep the door to the hall open as well," Ms Hegarty said. "Or, run your kitchen extractor fan or bathroom extractor fan all of the time. It will keep the air moving in a house."

People are also advised not to share bedrooms and to wear a mask when not eating.

Prof Wenger added that people should avoid sharing utensils, cutlery, glasses, and anything that could carry the virus on its surface.

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