ALBERTA – Ran Zhao, Associate Professor at the University of Alberta, held a webinar on Jan. 30 to share information on studies his group has done on indoor air quality.
“Thousands of these little particles are floating around, and they are detrimental to our health,” said Zhao.
“Although they are small, they are truly the silent killer in the air.”
He was referring to the PM 2.5 particles which are measured and widely used as a benchmark air pollutant around the world.
The Canadian governmental guideline is 27 micrograms of these tiny particles in every cubic meter of air over a 24-hour average according to Zhao.
Although the lower the PM 2.5 readings in the indoor air the better.
Air pollution is ranked as the number 4 risk factor with more than 6 million deaths every year.
Health issues caused by air pollution are varied including cardiovascular to neonatal disorders.
Zhao and his group have been studying indoor air and the effects of wildfire on degrading indoor air.
Two individual studies were performed and analyzed.
The first project evaluated indoor air and the effects of a humidifier with using multiple sensors throughout a house on different floors.
Indoor air is affected by the enclosed area ventilation and air exchange rates.
These influencers rule how long air pollutants stay within the indoor air.
Each household is unique as to the amount of outdoor air that is coming into the environment.
Pollutants can be introduced knowingly or unknowingly by the occupants.
One surprise that was revealed by Zhao was that humidifiers can add pollutants to indoor air, depending on the type of water that is being used.
The study showed that tap water contributes the highest number of pollutants to indoor air where distilled bottled water has the lowest contribution of pollutants.
The study positioned sensors close to the humidifier and in other rooms within the test house including the basement.
All sensors reported pollutant amounts from the humidifier with the smallest increases shown in the basement, but they were present in larger numbers on all floors than when no humidifier was running.
This study is especially relevant since many Albertans use humidifiers to combat the dry winter air in their homes.
Most manufacturers recommend using distilled water in humidifiers.
Consumers might not know that using tap water releases pollutants into the indoor air.
The type of humidifier also made a difference in the sensor readings.
Ultrasonic and evaporative humidifiers were used in the tests to evaluate how the PM 2.5 readings correlated with the components in the water.
The evaporative humidifier produced much lower pollutant readings than the ultrasonic models.
The PM 2.5 measurement of 15 micrograms per square meter is the standard Zhaos team used.
How does wildfire season impact indoor air?
Zhao and his team tested several campus buildings through wildfire season.
Outdoor sensor readings during the 2023 wildfire season were high, over 300 micrograms per cubic meter indicating the poor air conditions.
Buildings serve as protection for indoor air from outdoor wildfire smoke.
The indoor concentrations are always lower than outdoor readings.
Indoor sensors reported concentrations of 27 micrograms per cubic metre, above the Canadian standard.
Outdoor air does affect indoor air quality depending on the measures in each indoor space to reduce contaminates from entering.
The Government of Canada recommends keeping all doors and windows sealed during wildfire season to reduce exposure to the pollutants.
It’s not just trees burning.
The Canada.ca website sites everything from cigarette smoke, cooking, and using cleaning products contributing to the pollutants in indoor air.
In the study the buildings did maintain 27 micrograms per square metre most of the time.
Zhao had recommendations to consider in monitoring and improving your indoor air.
Having a sensor to test your indoor air can help you evaluate the conditions in your home.
Purifiers have benefits in reducing pollutants in the location’s indoor air and some purifiers have a reading mechanism as part of the unit.
It was recommended to buy high quality furnace filters to collect the pollutants being circulated in the indoor space.
Having a furnace filter attached to a box fan can be an inexpensive air purifier when the fan is running.
Zhao tested this method, and it worked.
Keeping an indoor space sealed during wildfire season can reduce wildfire pollutants within indoor air.
The University of Alberta provided a disclaimer stating that the webinar was general information and not professional advice and should not be considered a complete analysis.
You can check location air quality results online where it shows outdoor air quality and take actions to keep your indoor air protected when readings are high at www.iqair.com/ca/canada/alberta or airquality.alberta.ca/map/
