Concern over Covid-19 ventilation guidance ahead of indoor dining re-opening 

Expert group says carbon dioxide monitors are an effective means of identifying inadequate ventilation indoors, and that the information and advice contained therein 'should be used to update guidelines and sectoral advice'. File picture: Brian Lawless

A member of the Government’s expert group on ventilation has expressed concern that the various industries returning to work are “using guidance that isn’t scientifically up to date”.

The expert group’s two reports on how best to use ventilation in mitigating the risk of Covid-19 were officially published on Tuesday, three months after first being delivered to the National Public Health Emergency Team (Nphet).

The second report contains the expert group’s recommendations, including that carbon dioxide monitors are an effective means of identifying inadequate ventilation indoors, and that the information and advice contained therein “should be used to update guidelines and sectoral advice”.

“The sectors’ advice seems to be that ventilation should be considered ‘if it’s comfortable and if the weather’s good’,” Orla Hegarty, assistant professor at the UCD School of Architecture and a member of the expert group, told the Irish Examiner.

The recently released, updated guidelines for reopening restaurants and cafes published by Fáilte Ireland stress that indoor ventilation should be increased using outside air “as much as possible… taking into account weather and comfort level of room occupants”.

“At the moment, because sectors like gyms and hospitality have written their own guidelines, those rules are compromised by what the sectors think is practical, as opposed to what is necessary,” Ms Hegarty said.

She stressed the updated guidelines recently published across sectors “are really just add-ons to previous documents which stated that it’s all about surface hygiene and hand-washing”.

But we now know that there’s very little chance of you picking up the virus from a surface. I’m concerned that the sectors are using guidance that isn’t scientifically up to date.

“What is of the utmost importance now is that we get things right, not that we follow arbitrary rules of thumb,” she said, adding that sectoral guidance written from within those industries “should be subject to approval because when those guidelines go out people take them as being a sign of compliance”.

Indoor dining is set to return on July 5, with some trepidation among industry workers that the health measures in place in their workplaces may not be adequate to prevent surges of Covid-19.

The expert group’s reports meanwhile also recommend that air filtration devices “may be useful” in reducing airborne transmission of the virus in spaces with insufficient ventilation.

However, while such use of high-efficiency particulate air (HEPA) filters are an “easy-to-apply and cost-effective short-term mitigation measure, in the longer run they are not an effective alternative to improvements in a building’s ventilation", it said. 

“It is recognised that many improvements in ventilation may require architectural, engineering or operational changes,” it said, adding that they may require a longer timeframe to complete.

“It is therefore important that longer term strategies are considered in this context, and that steps are taken now to plan and prepare for next autumn and winter,” the report concludes.