Indoor Air Quality (IAQ)


Indoor air quality refers to the health and comfort levels of the air within our buildings. It is affected by gases (CO2, CO, radon, formaldehyde, toluene and other volatile organic compounds), particulates (including PM2.5), microbial contaminants (mold, bacteria), relative humidity and temperature.

Over the past few decades IAQ has become one of the greatest direct threats to our health, being responsible for numerous illnesses including asthma, nausea, skin and eye irritations, headaches, neurological damage, leukaemia and lung cancer.

The lack of awareness and regulation around this topic has resulted in indoor spaces that are far more dangerous than outdoors, a reality made worse by the fact that we spend the vast majority of our time indoors.

- For indoor air, concentration of individual air pollutants can easily be 100 times worse than outside. [1]

- The average person in Shanghai and Beijing spends 91% of their time indoors. [2]

- Formaldehyde in more than 92% of Chinese households is above the maximum allowable standard. 76% of the households are 5 times higher than the standard. [3]

- Indoor PM2.5 levels are about 75% of outdoor levels. Seeing as buildings tend to be negatively pressurized, particulates are pulled indoors and added to existing chemical cocktails. [4]

- Children are more susceptible to air pollution because their immune systems are not yet fully developed and they breathe in 50 percent more air per pound of body weight than adults. [5]

- PM 2.5 exposure has been correlated with birth weight deficits of 189g and smaller birth lengths of 1.1cm in male infants. [6]

- Cancer is the leading cause of death in China, with lung cancer claiming the most mortalities. [7]

- Lung cancer has risen 56% in Beijing over a decade, mainly due to air pollution. [8]

- 410,000 people (and rising) die each year due to air pollution in China. [9]


Without a doubt the most effective solution is to eliminate indoor air pollution at the source, especially when it comes to harmful chemicals such as formaldehyde. Most of the dangers of chemical off-gassing can be avoided by simply choosing the right materials. This critical step is by far the most powerful and the only way to identify safe materials is by choosing from those that have third-party IAQ certifications. GIGA enables users to focus on these materials by clicking on the IAQ filter. To make this even simpler and more powerful, we will soon be launching a IAQ calculator.

Although China has seen a recent rush towards portable air filters, they are unfortunately incomplete solutions. Although many are effective at filtering PM2.5, chemicals and bacteria within a relatively small area, they do not solve the problem of air exchange. The most important ingredient of healthy air is oxygen and indoor air rich with carbon dioxide must be regularly exchanged. Traditionally this has been achieved by opening and closing windows. Tragically, this is currently not an option in many Chinese citites seeing as opening windows floods interiors with harmful particulates. For this reason IAQ solutions require a properly designed air exchange and filtration system. These systems should also be combined with energy recovery ventilators in order minimize the loss of energy during the air exchange.

IAQ is part of IEQ (Indoor Environmental Quality), which includes other physical and psychological aspects of healthy interiors (e.g., lighting, visual quality and acoustics).

[1] PureLivingChina. Data taken over 600 projects across Shanghai and Beijing.
[2] GIGA. Survey in 2010 across 250 people

[3] Center for disease control in China, 2014
[4] PureLivingChina. Data taken over 600 projects across Shanghai and Beijing.
[5] "Children at Risk" Clean Air Task Force, May 2002
[6] “Gender differences in fetal growth of newborns exposed prenatally to airborne fine particulate matter.”  Wieslaw Jedrychowski, US National Library of Medicine National Institute of Health, Sept 30, 2013
[7] He J, Gu D, Wu X, et al. Major causes of death among men and women in China. N Engl J Med. 2005;353(11):1124–34.
[8] Beijing Institute for Cancer Research, 2011
[9] Beijing Institute for Cancer Research, 2009
server error: