Public buildings should mandate cleaner air

International group of scientists calls for indoor air quality standards to be introduced.

The 2019-20 bushfire season in Australia was unprecedented in its intensity and scale. An area the dimensions of Great Britain (59 million acres) burned. Billions of animals killed or displaced. Thousands of homes destroyed. Hundreds of lives were lost or irrevocably modified.

“It was also the first time that Australians really became aware of the importance of good indoor air quality,” he says Dear Professor Lidia Morawska from the Queensland University of Technology. “I did a lot of interviews during this time; what to do, how to protect people. I have given the advice to close the buildings as much as possible, make sure no air comes in from outside and if it is possible to avoid going outside then do it.”

Prof. Morawska is a physicist who has been studying air quality for greater than twenty years. She conducted research related to the SARS outbreak in 2003and established much of the basic understanding of how particles from respiratory activities (equivalent to respiration) behave indoors. “All of this knowledge and insight made me say, “Well, we clearly need to do something about ventilation in buildings and protecting people indoors from airborne transmission.”

Most people in urban and industrialized societies spend money 80 – 90% During their time indoors, ensuring the air they breathe is clean looks as if a very important thing, but she says that within the years that followed, it became increasingly difficult to persuade funders to support her work to support. “After the end of the SARS-1 epidemic, interest in it was very low for a very long time. It was next to impossible to get an indoor air quality grant. In 2014, one reviewer even noted that airborne transmission of infections was not possible!”

And then, in December 2019, the world modified.

The COVID-19 pandemic coupled with the Australian bushfires put air quality and ventilation within the highlight. “I spoke to the same journalists again” says Morawska, “But this time my advice was a 180° reverse – because of COVID I said open everything, don’t recirculate air, be outside as much as possible.”

“I remember very early in the pandemic seeing these huge signs that said ‘Wash Hands, Save Lives’ and thinking, ‘This isn’t going to save lives.'” Within days of seeing these posters, Morawska established what’s now called “the group of 36”all leading experts in air quality and aerosols. “That was when the first battle arose for the recognition of airborne transmission of infections.”

In the top Morawska was instrumental in it We must persuade the World Health Organization (WHO) and other relevant bodies to acknowledge that the coronavirus might be transmitted through the air – or more specifically, through exhalation and inhalation of virus-laden aerosols. And since then, she has continued to advocate for providing adequate indoor air quality in homes, schools and other spaces.

A call to motion

In one recent insights paper published this week in ScienceTogether with 42 other scientists, Prof. Morawska called for the introduction of national indoor air quality standards for public buildings. They have proposed maximum levels for carbon dioxide (CO).₂), carbon monoxide (CO) and particulate matter (PM_2.5) and a perfect ventilation rate (measured in liters per second per person).

“In most countries, there are no statutory standards for air quality in public spaces that address the concentration of pollutants in indoor air.” Prof. Morawska explains. This is in contrast to outside air, where national regulations and laws specify Minimum air quality standards were widely adopted.

For many reasons, regulating indoor air is a rather more complex undertaking. Indoor air accommodates rather more diverse spectrum of pollutants than the surface air, although some apply to each. Natural gas boilers emit nitrogen oxides (NO)._X), wood stoves produce PM_2.5, Building materials emit formaldehyde, volatile organic compounds are released from paint and carpets, flame retardants are sometimes added to furniture, and mold thrives in damp, poorly ventilated buildings. And then there are the emissions from the occupants of a constructing – us – we breathe out carbon dioxide and sometimes viruses and bacteria. The indoor air can be strongly influenced by the outdoor air (the other isn’t the case). This diversity makes it difficult to define what “good air” actually is.

Additionally, while cities often have quite a few monitoring stations to measure outdoor pollutants, this doesn’t apply to most public buildings. And even within the buildings where air quality measuring devices are installed, “We can’t rely on surveillance in one room to find out what’s happening in the room next door.” says Morawska. “In addition, there are still no technologies that can measure pathogens in real time. We really need surveillance in every room of a public building, which means it has to be done well, but in a much simpler, much more pragmatic way, otherwise it won’t be possible.”

The three metrics that Morawska and her colleagues presented of their paper might be viewed as useful, easily measured proxies for all other pollutants, and the proposed ventilation rate provides a solution to assess a constructing’s ventilation quality. The overall goal is to dilute and take away pollutants faster than they’re created to stop them from accumulating in indoor air.

“We propose a CO₂ Concentration level of 800 ppm [parts-per-million] with the proviso that the outdoor concentration is used as the base value,” says Morawska. “For PM_2.5We suggest using the WHO air quality guidelines as a basis [15 µg/m³]but shortening the averaging time.” They have also suggested 15-minute, 1-hour and 8-hour averages for CO levels, with 14 L/s per person being the optimal ventilation rate for an occupied space.

Achieving this will likely require costly retrofits or major redesign of public buildings – one other developing area of ​​research for Morawska – but she says the advantages are obvious: “Although there are short-term costs, the social and economic benefits to public health, well-being and productivity are likely to far outweigh the cost investments in clean indoor air.”