A Lack of Fresh Air
Written by Justin Gambill
Edited by Chloe Chou
Jan 23rd 2022
Edited by Chloe Chou
Jan 23rd 2022
With climate change becoming an increasingly pressing issue, the public health effects of such a phenomena are just beginning to materialize. A major topic in health studies in recent years has been the impact wildfire smoke has on the respiratory system. One study, conducted by Sydney Liebel et al,¹ examined the effects increased PM₂.₅ concentrations had on respiratory health of children in San Diego during the devastating Lilac Wildfire event in 2017. Particulate matter (PM) is often released when dry plant matter is burned, releasing small organic molecules within a larger smoke mixture.² PM₂.₅ refers to the particulate matter that is less than 2.5 microns in diameter: for reference, a strand of human hair is around 50-180 microns in diameter.²,³ The study itself revealed that increases in hospital visits at Rady Children’s Hospital were directly caused by the Lilac Fire, with an average increase in 16 pediatric visits per day being correlated with an average daily increase in PM₂.₅ concentration of 5.6 μm/m³.¹ Most of these visits came from residents who lived downwind from the fire, within 10 miles from its perimeter, indicating just how vast the exposure risk can be when the environmental conditions are just right.¹
Due to its small size, PM₂.₅ can cause major respiratory damage if inhaled in large quantities and can be especially dangerous in people with pre-existing respiratory illnesses and the small respiratory tracts of children.⁴ Smaller particles are particularly dangerous as they have the potential to penetrate deeper into the lung before they are absorbed, increasing the chances that the PM can inflict cellular damage.⁴ Inhalation of such particles has been shown to elicit an increased risk in cardiopulmonary disease or lung cancer, with PM₂.₅ having a strong potential to cause such harm, especially in children with developing respiratory systems.¹,⁵ Such adverse effects were especially relevent in those within the 0-5 year old age group studied.¹ As a reference point as to just how toxic this PM can be, a study conducted on Brazilian school children who were exposed to increased concentrations of PM₂.₅ (caused during similar fire events as experienced by the Lilac Fire in 2017) were shown to experience reduced lung function.⁶ With the many adverse effects PM₂.₅ can have on the respiratory system, developing ways to predict its concentration during natural disaster events can help predict how strained the health sector may become if respiratory-related hospital visits were to increase and could lead to better preparation to accommodate an influx in patients with similar respiratory needs.¹ In the case of the Lilac fire, a heavy influx of pediatric emergency room admissions potentially overwhelmed the health services, limiting access to much needed medical attention.¹
With that in mind, the increase in hospital visits was not surprising; similar increases in hospital visits in conjunction with a wildfire event were observed during fires in San Diego in 2007.⁷ The main issue is that these fire events will continue to occur at higher rates and intensities as the Earth’s climate continues to change. What the study conducted by Libel et al¹ revealed is that there is a dire need to develop accurate systems that can predict PM₂.₅ and other pollutant concentrations to allow better public health measures to be enacted in order to keep the population as safe as possible, especially as climate change continues to exacerbate the newly developing “fire season” here in California, as well as in other places around the world.
References
1. Leibel, Sydney; Nguyen, Margret; Brick, Willian; Parker, Jacob; Ilango, Sindana; Aguilera,
Rosana; Gershunov, Alexander; Benmarnhia, Tarik. “Increase in Pediatric Respiratory Visits Associated with Santa Ana Wind–Driven Wildfire Smoke and PM2.5 Levels in San Diego County.” Annals of the American Thoracic Society, vol. 17, no. 3, 2020, pp. 313–320., https://doi.org/10.1513/annalsats.201902-150oc.
2. “Particulate Matter (PM) Basics.” EPA, United States Environmental Protection Agency, 26
May2021, https://www.epa.gov/pm-pollution/particulate-matter-pm-basics.
3. “Size of the Nanoscale.” National Nanotechnology Initiative,
https://www.nano.gov/nanotech-101/what/nano-size.
4. Feng, Shaolong; Gao, Dan; Liao, Fen; Zhou, Furong; Wang, Xinming. “The Health Effects of
Ambient PM2.5 and Potential Mechanisms.”Ecotoxicology and Environmental Safety,
vol. 128, 2016, pp. 67–74. https://doi.org/10.1016/j.ecoenv.2016.01.030
5. Xing, Yu-Fei; Xu, Yue-Hua; Shi, Min-Hua; Lian, Ye-Xin. “The impact of PM2.5 on the
human respiratory system.” Journal of thoracic disease vol. 8,1 (2016): E69-74. https://doi.org/10.3978/j.issn.2072-1439.2016.01.19
6. Jacobson, Ludmilla da; de Souza Hacon, Sandra; Albuquerque de Castro, Hermano; Ignotti,
Elaine; Artaxo, Paulo; Carlos Monteiro Ponce de Leon, Antonio. “Association between Fine Particulate Matter and the Peak Expiratory Flow of Schoolchildren in the Brazilian Subequatorial Amazon: A Panel Study.” Environmental Research, vol. 117, 2012, pp. https://doi.org/10.1016/j.envres.2012.05.006.
7. Hutchinson, Justine A., et al. “The San Diego 2007 Wildfires and Medi-Cal Emergency
Department Presentations, Inpatient Hospitalizations, and Outpatient Visits: An Observational Study of Smoke Exposure Periods and a Bidirectional Case-Crossover Analysis.” PLOS Medicine, vol. 15, no. 7, 2018. https://doi.org/10.1371/journal.pmed.1002601
Image Source: “Wildfires, Fields, Road” by USFWS licensed under CC0