View source for F. Interplay Between Outdoor and Indoor Air Quality: The Dynamics of Sources, Ventilation, and Interactions

Despite the notion that opening a window can freshen the composition of indoor air, it is essential to recognise that outdoor air may contain a significant load of pollutants(88). Certain segments of the population, such as children, the elderly, pregnant women, and those with pre-existing health conditions, are particularly vulnerable to the adverse effects of air pollution on health(89). A notable concern is that individuals residing in low-income households are more likely to live near busy roads or industrial areas, leading to heightened exposure to air pollution(90).

The quality of indoor air is profoundly influenced by both indoor and outdoor sources of pollution(91). Key assumptions for synergy analysis include the understanding that outdoor air can infiltrate indoor environments and that indoor air pollution resulting from incomplete fuel combustion poses a direct health risk(92). Moreover, outdoor air quality can impact IAQ(93). 

Ventilation and insulation play crucial roles in determining the extent to which outdoor air pollutants affect indoor environments. Inadequate ventilation, where insufficient outdoor air enters indoor spaces, can lead to the accumulation of pollutants at levels that pose health and comfort challenges(94). Various mechanisms, including infiltration, natural ventilation, and mechanical ventilation, facilitate the exchange of outdoor and indoor air. These mechanisms can either bring outdoor pollutants indoors or effectively expel indoor pollutants, affecting IAQ. Interestingly, household air pollution, is a significant contributor to ambient air pollution, further underlines the interplay between indoor and outdoor air quality(95).

Reducing outdoor air pollution directly translates to a reduction in indoor pollution(96). As the performance of fireplaces, stoves, or boilers improves, the indoor-outdoor ratios decrease, indicating a reduction in the infiltration of outdoor pollutants. While existing literature predominantly focuses on various sources of pollution from biomass combustion, it lacks comparisons between different technologies. Nonetheless, the synergies between the objectives of curbing ambient air pollution and reducing indoor air pollution from residential biomass combustion are evident, highlighting the interconnectedness of indoor and outdoor air quality challenges(97).


=== ''' References ''' ===

(88) The European Environment Agency, “Air Quality in Europe 2019 Report,” Publications Office of the European Union, 2019. Available online: https://www.miteco.gob.es/content/dam/miteco/es/calidad-y-evaluacion-ambiental/temas/atmosfera-y-calidad-del-aire/air-quality-in-europe_2019_tcm30-187944.pdf 

(89) The European Environment Agency, “Air Quality in Europe 2019 Report,” Publications Office of the European Union, 2019. Available online: https://www.miteco.gob.es/content/dam/miteco/es/calidad-y-evaluacion-ambiental/temas/atmosfera-y-calidad-del-aire/air-quality-in-europe_2019_tcm30-187944.pdf 

(90) The European Environment Agency, “Air Quality in Europe 2019 Report,” Publications Office of the European Union, 2019. Available online: https://www.miteco.gob.es/content/dam/miteco/es/calidad-y-evaluacion-ambiental/temas/atmosfera-y-calidad-del-aire/air-quality-in-europe_2019_tcm30-187944.pdf
 
(91) The European Court of Auditors, “Special Report no 23/2018: Air Pollution: Our health still insufficiently protected,” 10 September 2018. Available online: https://www.eca.europa.eu/en/publications?did=46723

(92) Study to support the impact assessment for a revision of the EU Ambient Air Quality Directives, the European Commission, October 2022. Available online: https://op.europa.eu/en/publication-detail/-/publication/a05c2e91-54db-11ed-92ed-01aa75ed71a1/language-en

(93) 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  ;The United States Environmental Protection Agency, “Introduction to Indoor Air Quality,” The United States Environmental Protection Agency, 16 May 2023. Available online:  https://www.epa.gov/indoor-air-quality-iaq/introduction-indoor-air-quality#:~:text=Indoor%20Air%20Quality%20(IAQ)%20refers,and%20comfort%20of%20building%20occupants. 
 
(94) The United States Environmental Protection Agency, “Introduction to Indoor Air Quality,” The United States Environmental Protection Agency, 16 May 2023. Available online:  https://www.epa.gov/indoor-air-quality-iaq/introduction-indoor-air-quality#:~:text=Indoor%20Air%20Quality%20(IAQ)%20refers,and%20comfort%20of%20building%20occupants.

(95) The World Health Organisation, “Household Air Pollution,” 28 November 2022. Available online: https://www.who.int/news-room/fact-sheets/detail/household-air-pollution-and-health

(96) The United States Environmental Protection Agency, “Introduction to Indoor Air Quality,” The United States Environmental Protection Agency, 16 May 2023. Available online:  https://www.epa.gov/indoor-air-quality-iaq/introduction-indoor-air-quality#:~:text=Indoor%20Air%20Quality%20(IAQ)%20refers,and%20comfort%20of%20building%20occupants. 

(97) The United States Environmental Protection Agency, “Introduction to Indoor Air Quality,” The United States Environmental Protection Agency, 16 May 2023. Available online:  https://www.epa.gov/indoor-air-quality-iaq/introduction-indoor-air-quality#:~:text=Indoor%20Air%20Quality%20(IAQ)%20refers,and%20comfort%20of%20building%20occupants. 






[[Category: IAQ Policy Landscape]]