How to measure air quality at home

Published on 14 January, 2019


Environmental pollution reduces quality and even life expectancy. Knowing how to measure air quality at home is a very important factor for health, because nowdays people spend between 80 and 90% of their time in closed environments. Indoor air pollution, with levels of pollutants is between 2 and 5 times more concentrated than outside.

In addition, the seriousness of the problem varies depending on the country: while in Spain the expectation is reduced in almost 3 months, in India it can represent up to 1.5 years less (Apte et al., 2018).

What is indoor air quality?

According to the US Environmental Protection Agency (EPA), indoor air quality is perceived “within and around buildings and structures”, paying special attention to “the health and comfort of building occupants”.

This factor will depend, to a great extent, on the activities undertaken inside the house or the building materials or the products frequently used. However, it is worth mentioning that some pollution comes from outdoors through air-cooling systems, natural ventilation or infiltration (Leung, 2015).

Main sources and pollutants?

The following image shows several of the most usual pollutants indoors.

how to measure air quality

Indoor air quality. Source: European Environment Agency CC BY 2.5 DK

Cigarette smoke, for example, is one of the main pollutants and a source of toxic gases such as carbon monoxide (CO), nicotine -which can be considered as a semi-volatile compound-, or particles whose diameter is smaller than 2,5μm (PM2.5). These suspended particles also come from electronic cigarettes or e-cigarettes, adding the risks of passive exposure (Jimenez Ruiz et al., 2019).

Heating systems and kitchens without ventilation can generate suspended particles (PM1, PM2.5 and PM10) or gases (CO, nitrogen oxides, etc.). In the areas of the Earth with fewer resources, this has become a significant cause of death -more than 4 million deaths per year, according to WHO.

Chemical domestic products (cleaning products, paint, insecticides, paint-removing products, personal hygiene, etc.) are one of the main sources of volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs). Some of the most famous (and harmful) of these compounds are benzene, trichloroethane or vinyl chloride.

The building materials in a house can also contribute to worsening indoor air quality. Asbestos is one of the most famous, but fiberglass can also be decomposed over the years or because of humidity and emit particles.

Other pollution factors

Pets, beds or upholsteries, apart from being a refuge for all kinds of allergens (mites, for example), can also generate volatile organic compounds or suspended particles that, thanks to their small size, can enter the bloodstream.

Other important factors that must be taken into account inside a house are: humidity, which may provoke the appearance of mold; cooling or heating systems with a poor maintenance, which may cause the appearance of microorganisms; or radon, a natural gas found in the soil whose concentration depends on the kind of land on which the house has been built.

The following table, inserted as a summary of the above and based on the paper Preventing noncommunicable diseases (NCDs) by reducing environmental risk factors (OMS, 2017), displays the percentage of deaths due to noncommunicable diseases related to environmental risks.

How can you know the air quality in a closed room?

Once we have listed the main sources and pollutants and the health problems provoked by polluted air, the following step is learning how to monitor air quality at home, because what you don’t know, you can’t appreciate nor take care of it.

The devices included in the Internet of Things (IoT) make possible continuous real-time monitoring of environmental conditions at home, thus helping to preserve people’s health and warning, for example, when it is necessary to ventilate a room. The sensors usually inserted in these devices are more and more accurate and reliable nowadays. The model Nanoenvi IAQ, for example, can be tailored according to the client’s needs with up to 5 sensors chosen from a large list.

Users can access the information transmitted through these devices, among which it is worth mentioning the model Nanoenvi IAQ (analyzing parameters such as CO2, VOC, CO, PM10 and PM2.5), by means of mobile applications in smartphones or tablets, thus having complete information available to make their homes habitable spaces and not mortal traps.


–       Apte, J., Brauer, M., Cohen, A., Ezzati, M., & Pope, C. (2018). Ambient PM2.5 Reduces Global and Regional Life Expectancy. Environmental Science & Technology Letters, 5(9), 546-551. doi:

–       Leung, D. (2015). Outdoor-indoor air pollution in urban environment: challenges and opportunity. Frontiers In Environmental Science, 2. doi:

–       Jimenez Ruiz, C., Solano Reina, S., de Granda Orive, J., Signes-Costa Minaya, J., de Higes Martinez, E., & Riesco Miranda, J. et al. (2014). El cigarrillo electrónico. Declaración oficial de la Sociedad Española de Neumología y Cirugía Torácica (SEPAR) sobre la eficacia, seguridad y regulación de los cigarrillos electrónicos. Archivos De Bronconeumología, 50(8), 362-367. doi:

–       World Health Organization. (‎2017)‎. Preventing noncommunicable diseases (‎NCDs)‎ by reducing environmental risk factors. World Health Organization. Licencia: CC BY-NC-SA 3.0 IGO

How to measure air quality at home

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