Why is Indoor Air Quality Important?
Indoor Air Quality (IAQ) refers to how good the air is in our homes, our schools and other public spaces. Until recently, most people hadn’t given the air that we breathe indoors much consideration. But it’s an invisible risk and the US Environmental Protection Agency ranks it as one of the top five environmental dangers. We spend 90% of our time inside buildings where the concentration of pollutants can be up to five times higher than outside.
The effect of ventilation on disease transmission was recognised by Florence Nightingale in 1859 (during the time of tuberculosis) and buildings were designed with far better ventilation as a result. Over time, the focus on energy efficiency has seen many of those ventilation enhancements in old buildings removed and newer builds have not given it sufficient priority.
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Concentrations of some pollutants have increased in recent decades due to: energy-efficient building construction, increased use of synthetic building materials, furnishings, personal care products and household cleaners.
The Covid-19 pandemic again exposed the problem of ignoring indoor air quality; this has spurred a renewed focus on poor ventilation. The air quality in buildings is critical for minimizing the spread of airborne infectious diseases and reducing the triggers for chronic illnesses.
Members of our society who are most susceptible to the adverse effects of pollution – the very young, the elderly, people suffering from health conditions – spend even more time indoors.
Children are more vulnerable to the adverse effects of poor air quality because their brains and bodies are still developing. However research has shown simple interventions in schools have the potential to significantly improve children’s health.
“Schools should be safe places of learning, not places where students are at risk of health hazards” Dr Maria Neira, WHO
What are Indoor Air Pollutants?
Fine Particulate Matter (PM2.5)
Produced by vehicles, heavy industry and wood burning.
Pathogens
Viruses and Bacteria produced by people breathing can linger in the air for hours in densely occupied spaces. Viruses include: influenza, Covid-19, RSV and measles. Bacteria include: tuberculosis, diphtheria and streptococci.
Mould and fungal spores are caused by damp, poorly ventilated buildings.
Gases
Carbon Dioxide (CO2) is produced by stoves and humans breathe out CO2. In poor ventilation, the CO2 can quickly build up.
Carbon Monoxide is a colourless, odourless gas that is highly poisonous. It can build up to dangerous levels in enclosed spaces which can be fatal.
Nitrogen Dioxide (NO2) from coal-fired power plants and road traffic.
Sulphur Dioxide is a stinky colourless gas. It is released into the environment during the burning of coal and oil. Sources include power plants, oil refineries, some motor vehicles and domestic boilers.
Radon Gas is created when natural radioactive uranium decays in the ground under our buildings and seeps to the surface.
Volatile Organic Compounds (VOC)
These are gaseous chemicals found in many common household items, such as building materials, soft furnishings, cleaning products, cosmetics and art & craft materials.
The most common indoor VOCs include formaldehyde, benzene, acetone, xylene, and ethanol.
The concentration of VOCs can be up to ten times higher inside homes than outside; they can remain present in indoor air for several hours. Exposure to VOCs can lead to short and long-term adverse health effects.
Larger Particles (PM10)
Dust is powder-like particles including clothing fibres, pet hairs, soil and dust mites. PM10 also includes dust from construction sites, landfills, agriculture, wildfires, industrial sources and wind-blown dust from open land.
Pollen produced by plants and trees; it is a significant problem for asthma sufferers.
Benefits of Safer Air
In addition to decreased infectious disease transmission, research shows that ventilation and air filtration lead to improved academic performance, fewer missed school days for students and higher scores on cognitive function tests.
Also there are benefits for teachers including decreased respiratory symptoms, increased staff retention, and improved morale.
The Finland Study
A recent study led by E3 Pandemic Response and conducted in Finland, demonstrated positive results. Air filters were placed in two daycare centres which led to a reduction in illnesses and absences among children and staff.
The initial results from the first year of research are promising, according to researcher Enni Sanmark, from HUS Helsinki University Hospital. “Children were clearly less sick in [these] daycare centres — down by around 30 percent” Sanmark explained.
“The air [filters] were changed at two daycare centres serving as a control in the experiment, in order to rule out the effect that possible epidemic fluctuations could have on the results. The study’s next phase will continue until April. We will be able to analyse whether there were only decreases in flu-type illnesses or whether the use of air purification could also help reduce stomach ailments,” Sanmark said.
“At the moment, we are cautiously positive. Daycares and schools [here] have not done this before, but of course results from around the world show that air purification can reduce pathogens in the air, so our results are in line with these findings. We’re excited and will continue our research.”