Editing Wildfire (section)

=== Airborne hazards ===
{{See also|Heavy metals#Toxicity|Health effects of wood smoke|Joss paper#Health impact}}
The most noticeable adverse effect of wildfires is the destruction of property. However, hazardous chemicals released also significantly impact human health.<ref>{{Cite web |date=5 February 2019 |title=How Have Forest Fires Affected Air Quality in California? |url=https://www.purakamasks.com/how-did-forest-fires-affect-air-quality-in-california |access-date=11 February 2019 |website=www.purakamasks.com |language=en}}{{Dead link|date=February 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

Wildfire smoke is composed primarily of carbon dioxide and water vapor. Other common components present in lower concentrations are carbon monoxide, formaldehyde, [[acrolein]], polyaromatic hydrocarbons, and benzene.<ref name="oehha.ca.gov">{{Cite web |last=Office of Environmental Health Hazard Assessment |year=2008 |title=Wildfire smoke: A guide for public health officials |url=http://oehha.ca.gov/air/risk_assess/wildfirev8.pdf |url-status=live |archive-url=https://web.archive.org/web/20120516071549/http://www.oehha.ca.gov/air/risk_assess/wildfirev8.pdf |archive-date=16 May 2012 |access-date=9 July 2012}}</ref> Small airborne particulates (in solid form or liquid droplets) are also present in smoke and ash debris. 80–90% of wildfire smoke, by mass, is within the fine particle size class of 2.5 micrometers in diameter or smaller.<ref>{{Cite web |last=National Wildlife Coordination Group |year=2001 |title=Smoke management guide for prescribed and wildland fire |url=http://www.fs.fed.us/pnw/pubs/ottmar-smoke-management-guide.pdf |url-status=live |archive-url=https://web.archive.org/web/20161011200515/http://www.fs.fed.us/pnw/pubs/ottmar-smoke-management-guide.pdf |archive-date=11 October 2016 |publisher=National Interagency Fire Center |location=Boise, ID}}</ref>

Carbon dioxide in smoke poses a low health risk due to its low toxicity. Rather, carbon monoxide and fine [[particulate matter]], particularly 2.5&nbsp;μm in diameter and smaller, have been identified as the major health threats.<ref name="oehha.ca.gov" /> High levels of [[heavy metals]], including [[lead]], [[arsenic]], [[cadmium]], and copper were found in the ash debris following the 2007 Californian wildfires. A [[national clean-up campaign]] was organised in fear of the health effects from exposure.<ref>{{Cite journal |vauthors=Finlay SE, Moffat A, Gazzard R, Baker D, Murray V |date=November 2012 |title=Health impacts of wildfires |journal=PLOS Currents |volume=4 |pages=e4f959951cce2c |doi=10.1371/4f959951cce2c |doi-broken-date=1 November 2024 |pmc=3492003 |pmid=23145351 |doi-access=free}}</ref> In the devastating California [[Camp Fire (2018)]] that killed 85 people, lead levels increased by around 50 times in the hours following the fire at a site nearby ([[Chico, California|Chico]]). [[Zinc]] concentration also increased significantly in Modesto, {{convert|150|mi|km|order=flip}} away. Heavy metals such as [[manganese]] and calcium were found in numerous California fires as well.<ref>{{Cite web |date=21 July 2021 |title=Wildfire smoke can increase hazardous toxic metals in air, study finds |url=https://www.theguardian.com/world/2021/jul/21/wildfire-smoke-air-hazardous-toxic-metals-study-california |website=the Guardian}}</ref> Other chemicals are considered to be significant hazards but are found in concentrations that are too low to cause detectable health effects.{{citation needed|date=May 2023}}

The degree of wildfire smoke exposure to an individual is dependent on the length, severity, duration, and proximity of the fire. People are exposed directly to smoke via the respiratory tract through inhalation of air pollutants. Indirectly, communities are exposed to wildfire debris that can contaminate soil and water supplies.

The [[United States Environmental Protection Agency|U.S. Environmental Protection Agency]] (EPA) developed the [[air quality index]] (AQI), a public resource that provides national air quality standard concentrations for common air pollutants. The public can use it to determine their exposure to hazardous air pollutants based on visibility range.<ref>{{Cite web |last=U.S. Environmental Protection Agency |year=2009 |title=Air quality index: A guide to air quality and health |url=http://www.epa.gov/airnow/aqi_brochure_08-09.pdf |url-status=live |archive-url=https://web.archive.org/web/20120507130507/http://www.epa.gov/airnow/aqi_brochure_08-09.pdf |archive-date=7 May 2012 |access-date=9 July 2012}}</ref>