B. Understanding Indoor Air: Challenges and Differences from Outdoor Air

While the prevailing perception is that pollution primarily poses a risk outdoors⁽¹⁰⁾, it is important to recognise that indoor environments can harbour pollution levels that are not only comparable but often exceed those found outdoors⁽¹¹⁾. Indoor Air Quality (IAQ) can be significantly compromised by elements like smoke, mould and chemicals present in certain paints, furnishings, and cleaning products⁽¹²⁾. In contrast to ambient air quality, which pertains to outdoor settings, indoor air quality encompasses the air within and surrounding buildings, with an emphasis on the comfort, well-being, and health of occupants. Given that Europeans spend 90% of their time indoors⁽¹³⁾ and that indoor spaces can sometimes be more polluted than outdoor areas⁽¹⁴⁾, comprehending the full scope of this issue and devising strategies to enhance air quality is seen as paramount both in Europe and globally.

Since the 1970s, the matter of IAQ has garnered considerable attention, with the World Health Organization addressing it in various documents and forums⁽¹⁵⁾. This problem is acknowledged as a pressing concern spanning low, middle, and high-income countries alike⁽¹⁶⁾. Individuals can encounter air pollutants in a range of indoor settings, encompassing private residences, offices, educational institutions, and public transportation systems⁽¹⁷⁾. The complexity arises from the fact that indoor air often comprises a blend of diverse pollutants, making it intricate to pinpoint the health implications linked to specific exposures⁽¹⁸⁾. Furthermore, the quality of indoor air is influenced by a multitude of factors, including the activities conducted in each space, the quality of building materials and finishes, the furnishings present, and even the level of occupancy, among others⁽¹⁹⁾. Moreover, it's worth noting that indoor environments can also be impacted by outdoor pollutants seeping in⁽²⁰⁾.

References

(10) The National Institute of Environmental Health Sciences, “Indoor Air Quality,” 12 July 2023. Available online: https://www.niehs.nih.gov/health/topics/agents/indoor-air/index.cfm

(11) Abinaya Sekar et al, “Analysis of benzene air quality standards, monitoring methods and concentrations in indoor and outdoor environment,” Heliyon, 29 November 2019. Available online: https://pubmed.ncbi.nlm.nih.gov/31844766/

(12) The National Institute of Environmental Health Sciences, “Indoor Air Quality,” 12 July 2023. Available online: https://www.niehs.nih.gov/health/topics/agents/indoor-air/index.cfm

(13) Maya I Mitova et al, “Human chemical signature: Investigation on the influence of human presence and selected activities on concentrations of airborne constituents,” Environmental Pollution, February 2020. Available online: https://www.sciencedirect.com/science/article/pii/S0269749119334268

(14) Abinaya Sekar et al, “Analysis of benzene air quality standards, monitoring methods and concentrations in indoor and outdoor environment,” Heliyon, 29 November 2019. Available online: https://pubmed.ncbi.nlm.nih.gov/31844766/

(15) Gaetano Settimo et al, “Indoor Air Quality: A Focus on the European Legislation and State-of-the-Art Research in Italy,” MDPI, 1 March 2020. Available online: https://www.mdpi.com/2073-4433/11/4/370#B6-atmosphere-11-00370

(16) Michael J Suess, “The Indoor Air Quality Programme of the WHO Regional Office for Europe,” the WHO regional office for Europe, 1992, 2, 180–193. Available online: https://www.aivc.org/sites/default/files/airbase_6487.pdf ; Lars Mølhave et al, “The right to healthy indoor air: Status by 2002,” National Library of Medicine, 2003. Available online: https://pubmed.ncbi.nlm.nih.gov/12572915/ ; The World Health Organisation, “WHO Guidelines for Indoor Air Quality,” the WHO regional office for Europe, 2010. Available online: https://www.who.int/publications/i/item/9789289002134

(17) Directorate General for Health and Consumer Affairs, “Indoor Air Quality,” the European Commission, 2008. Available online: https://ec.europa.eu/health/scientific_committees/opinions_layman/en/indoor-air-pollution/l-2/5-pollutant-mixtures.htm#0

(18) Directorate General for Health and Consumer Affairs, “Indoor Air Quality,” the European Commission, 2008. Available online: https://ec.europa.eu/health/scientific_committees/opinions_layman/en/indoor-air-pollution/l-2/5-pollutant-mixtures.htm#0

(19) Directorate General for Health and Consumer Affairs, “Indoor Air Quality,” the European Commission, 2008. Available online: https://ec.europa.eu/health/scientific_committees/opinions_layman/en/indoor-air-pollution/l-2/5-pollutant-mixtures.htm#0 ; Gaetano Settimo et al, “Indoor Air Quality: A Focus on the European Legislation and State-of-the-Art Research in Italy,” MDPI, 1 March 2020. Available online: https://www.mdpi.com/2073-4433/11/4/370#B6-atmosphere-11-00370

(20) Directorate General for Health and Consumer Affairs, “Indoor Air Quality,” the European Commission, 2008. Available online: https://ec.europa.eu/health/scientific_committees/opinions_layman/en/indoor-air-pollution/l-2/5-pollutant-mixtures.htm#0