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Measurement of indoor air quality: In what areas does it matter?

Published on 25 June, 2019

Indoor air quality,

Indoor air quality monitoring arouses less concern than outdoor air quality monitoring.

This is attested by surveys such as the one conducted in the United Kingdom during Clean Air Day 2018. This consultation revealed that only 36% of adults were aware of the effects of indoor pollution on health. The impact of external pollution, on the other hand, was known by 85% of the people consulted (Clean Air Day, 2018).

However, the indoor air quality recorded is often lower than the outdoor air quality. Therefore, and keeping in mind that people spend around 90% of the time in closed spaces (Klepeis et al., 2001), the monitoring of these environments must become a priority action to improve the comfort of people and promote a safe and pleasant atmosphere.

Spaces where to monitor air quality

All crowded confined areas should have devices to monitor the quality of indoor air as Nanoenvi IAQ, a solution developed to monitor parameters such as CO2, CO, suspended particles, VOCs, temperature, percentage of humidity or even noise levels.

The following sections detail some of these enclosures.

Educational centers and libraries

The child population is one of the groups most at risk when they are exposed continuously to poor air quality. This circumstance is due to the fact that their organisms, still in development, have fewer mechanisms to deal with the impact of polluting agents.

What are the consequences of exposure to poor indoor air quality conditions? Asere and Blumberga (2018), citing various studies, claim, for example, that “excess CO2 (more than 1000 ppm) and indoor air VOC levels cause acute health effects such as eye irritation and skin irritation, respiratory tract, headaches, dizziness, loss of coordination, nausea, visual disturbances and allergic reactions, including asthma and rhinitis. Higher levels of VOCs can have chronic adverse health effects, such as damage to the liver, kidneys, blood system and central nervous system. Some VOCs, such as formaldehyde, can even cause cancer in humans.”

The improvement of environmental conditions is also closely related to school performance, with research suggesting an increase of 3-8% in efficiency (2).

Hospitals and health care centers

People admitted to a health center or under medical treatment, as well as the staff working in these facilities, may experience health problems because of environmental issues. For example, parameters such as temperature or humidity directly influence both thermal comfort and the spread of germs, while pollutants such as CO or NO2, sometimes from outside, can cause respiratory problems, fatigue or nausea. The correct operation of the ventilation systems, complemented by sensors that monitor environmental conditions in real time, acquires special importance in this case. According to the research carried out by the BPIE, the improvement of air quality in health centers, in addition to achieving a more pleasant atmosphere, also has the following positive effects:

➢ The length of stay of patients can be reduced by 11%.

➢ The cost of medication is reduced by up to 21%.

➢ The mortality rate in a children’s hospital was reduced by up to 19%.

➢ Employee turnover is reduced by up to 20%.

➢ The reduction of noise levels has positive effects on heart rate, pulse, breathing and sleep.

Cultural, leisure or sports spaces

This heading includes tourist attractions such as museums or monuments, equipment linked to cultural and leisure activities (cinemas, theaters, auditoriums, etc.), covered sports centers and shopping centers. They are places where hundreds or thousands of people come together, so it is very important to monitor indoor air quality.

The monitoring of the environmental parameters inside these enclosures is not only a way to increase the satisfaction and comfort of visitors. It is also a way to protect and safeguard the works of art that are exhibited in museums, for example, since the deposition of particulate material from outside and introduced through ventilation systems can damage and soil these valuable elements (Nazaroff, Salmon & Cass, 1990).

Public transport

The facilities linked to transport services (airports, railway stations, metro, etc.) daily support the transit of thousands of people. Ensuring that the air quality is adequate allows people to enjoy a pleasant atmosphere during the wait. In facilities such as the subway, for example, it is convenient to monitor parameters such as temperature, humidity or particles in suspension, both at stations and inside trains.


Indoor air quality is a factor directly related to people’s performance. It is at least one of the conclusions reached by research such as the one carried out by the National University of Singapore, which found lower industrial production in the face of continuous exposures at high concentrations of PM2.5 (3).

In the specific case of the offices and citing the BPIE study (2), the improvement of environmental conditions results in the following benefits:

➢ The reduction of 1 ° C in offices with high temperatures (> 25 ° C according to Niemelä, Hannula, Rautio, Reijula ​​and Railio, 2002) increases the worker’s performance by 3.6%.

➢ Each increase of 1 liter per second per person in ventilation increases the worker’s performance by 0.8%.

➢ Each 100 lux of increase in the level of illumination increases the worker’s performance by 0.8%.

➢ For every 1 dB of decrease in excess noise, the performance improves by 0.3%.

Private homes

At home, the activities that take place inside (cooking, cleaning, smoking, etc.), the construction materials and furniture or daily use products (insecticides, cleaning products, etc.), condition the air quality.

Considering that, together with work or educational centers, private homes are one of the places where people spend most time, ensuring adequate air quality is essential, especially if there are people belonging to a risk group (children, elderly or sick people). Hence, monitoring solutions such as those developed by ENVIRA are also useful at home to know when it is necessary to ventilate a room, for example.

The monitoring of indoor air quality is, in short, a recommended activity for any area or facility in which people live or meet on a regular basis. The goal is to ensure an atmosphere free of threats and a comfortable stay that maximizes productivity and satisfaction.


– (1) Indoor air pollution. (2014). https://www.europeanlung.org/es/pulmonary-diseases-and-information/factors-of-risk/the-internal-air-contamina-tion
– (2) Building 4 People: Quantifying the benefits of energy renovation investments in schools, offices and hospitals | BPIE – Buildings Performance Institute Europe. (2018). http://bpie.eu/publication/building-4-people-valorising-the-benefits-of-energy-renovation-investments-in-schools-offices-and-hospitals/
– (3) National University of Singapore. (2019, January 3). Severe air pollution affects the productivity of workers: Prolonged exposure to pollutant particles is shown to reduce the output of workers in China. ScienceDaily www.sciencedaily.com/releases/2019/01/190103110735.htm
– Asere, L., & Blumberga, A. (2018). Energy efficiency – indoor air quality dilemma in public buildings. Energy Proceia, 147, 445-451. doi: http://doi.org/c3gf
– Clean Air Day. (2018). Clean Air Day 2018: Celebrating the impact of the UK’s largest air quality campaign [PDF] (page 19). Clean Air Day coordinated by Global Action Plan. https://www.cleanairday.org.uk/Handlers/Download.ashx?IDMF=88367ca5-e3df-45a6-86bf-9d9f62496f3e
– Klepeis, N., Nelson, W., Ott, W., Robinson, J., Tsang, A., & Switzer, P. et al. (2001). The National Human Activity Pattern Survey (NHAPS): a resource for assessing exposure to environmental pollutants. Journal of Exposure Science & Environmental Epidemiology, 11 (3), 231-252. doi: http://doi.org/fjw2rt
– Nazaroff, W. W., Salmon, L. G., & Cass, G. R. (1990). Concentration and fate of airborne particles in museums. Environmental Science & Technology, 24 (1), 66-77.doi: http://doi.org/crf4vb
– Niemelä, R., Hannula, M., Rautio, S., Reijula, K., & Railio, J. (2002). The effect of air temperature on labor productivity in call centers-a case study. Energy And Buildings, 34 (8), 759-764. doi: http://doi.org/dkggtz

Measurement of indoor air quality: In what areas does it matter?

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