Covid-19: Public health advice not reflecting need for good ventilation, TDs told

UCD academic tells Oireachtas committee of ‘resistance’ to admitting disease spreads via aerosols

Ireland's response to the Covid-19 pandemic has not placed enough focus on examining air quality and promoting good ventilation, the Oireachtas health committee has heard.

Orla Hegarty, of University College Dublin’s school of architecture, planning and environmental policy, said the public health advice has failed to get across the importance of good ventilation in preventing the spread of the disease.

“In buildings and vehicles, [viral particles] can build up, fill a space, linger for hours, and infect many people. Viral particles in the air behave like smoke and must be cleared out,” she said.

Ms Hegarty, a member of the Expert Advisory Group on Ventilation and Covid-19, said there initially was “resistance” to admitting Covid-19 spreads through aerosols and that the main focus was on hand hygiene.


“I don’t feel the response has been adequate. I don’t think the public health message has been clear. The vast majority of people don’t know why [ventilation] is important,” she said.

Ms Hegarty said ventilation had formed a key part of the initial pandemic response in Asian countries but this had not been the case in most English-speaking western countries.


“They have been extremely slow, and I would say resistant even, to adopting this as part of their pandemic response.”

She viewed enclosed spaces such as vehicles and overcrowded housing as high risk.

“Inadequate space in institutional and shared housing is high risk, such as in dormitories, hostels, emergency homeless accommodation and direct provision centres,” she said.

“[Direct provision centres] saw 82 outbreaks with an average of 10 cases, and Traveller and Roma housing saw 423 outbreaks with an average of 12 cases.”

Ms Hegarty said that providing better public health information on the importance of ventilation is key to reducing the spread of Covid-19.

Other measures she recommended included reducing the number of people in a building and limiting certain activities such as shouting, singing and exercising, which increase transmission.

Ms Hegarty said measuring “stale air” by using carbon dioxide monitors can give buildings like schools an indication of their air quality, and alert them when to open windows and doors.

HEPA air purifiers, which clean the air, could also be used in these settings, and may greatly improve air quality in hospitality, nursing homes and childcare settings, where masks cannot be worn, she said.

“It’s very basic, a fan and a filter.”

Own guidance

She also expressed concerns that many sectors are “writing their own guidance” in relation to ventilation. “There’s no scientific review... they are trying their best... but we need a coordinated approach.”

Ms Hegarty added that education was one of the few sectors that “took ventilation seriously”, but it needed more support ahead of the new school year in September as children will not be vaccinated.

“More than one in four schools has had a Covid-19 index case since February, and in total there have been 2,460 cases linked to 579 outbreaks in schools,” she said. “Last week, there were 61 outbreaks in schools, which was 20 per cent of all outbreaks, more than any other category, excluding homes.”

Ms Hegarty added that there have been 1,966 close contact cases in childcare since the sector reopened in July, and 342 outbreaks in some 900 childcare buildings.

TDs and Senators on the committee also raised concerns that the minutes of the Expert Advisory Group on Ventilation and Covid-19, and their letters containing their expert advice, were not being made public regularly.