Editing Wildfire (section)

==== Asthma exacerbation ====
Several epidemiological studies have demonstrated a close association between [[air pollution]] and respiratory allergic diseases such as bronchial [[asthma]].<ref name=":11" />

An observational study of smoke exposure related to the 2007 San Diego wildfires revealed an increase both in healthcare utilization and respiratory diagnoses, especially [[asthma]] among the group sampled.<ref name=":13">{{Cite journal |last1=Hutchinson |first1=Justine A. |last2=Vargo |first2=Jason |last3=Milet |first3=Meredith |last4=French |first4=Nancy H.F. |last5=Billmire |first5=Michael |last6=Johnson |first6=Jeffrey |last7=Hoshiko |first7=Sumi |date=10 July 2018 |title=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 |journal=PLOS Medicine |volume=15 |issue=7 |pages=e1002601 |doi=10.1371/journal.pmed.1002601 |issn=1549-1676 |pmc=6038982 |pmid=29990362 |doi-access=free}}</ref> Projected climate scenarios of wildfire occurrences predict significant increases in respiratory conditions among young children.<ref name=":13" /> PM triggers a series of biological processes including inflammatory immune response, [[oxidative stress]], which are associated with harmful changes in allergic respiratory diseases.<ref>{{Cite journal |last1=Wu |first1=Jin-Zhun |last2=Ge |first2=Dan-Dan |last3=Zhou |first3=Lin-Fu |last4=Hou |first4=Ling-Yun |last5=Zhou |first5=Ying |last6=Li |first6=Qi-Yuan |date=8 June 2018 |title=Effects of particulate matter on allergic respiratory diseases |journal=Chronic Diseases and Translational Medicine |volume=4 |issue=2 |pages=95–102 |doi=10.1016/j.cdtm.2018.04.001 |issn=2095-882X |pmc=6034084 |pmid=29988900}}</ref>

Although some studies demonstrated no significant acute changes in lung function among people with [[asthma]] related to PM from wildfires, a possible explanation for these counterintuitive findings is the increased use of [[Asthma|quick-relief medications]], such as inhalers, in response to elevated levels of smoke among those already diagnosed with [[asthma]].<ref name=":14">{{Cite journal |last1=Reid |first1=Colleen E. |last2=Brauer |first2=Michael |last3=Johnston |first3=Fay H. |last4=Jerrett |first4=Michael |last5=Balmes |first5=John R. |last6=Elliott |first6=Catherine T. |date=15 April 2016 |title=Critical Review of Health Impacts of Wildfire Smoke Exposure |journal=Environmental Health Perspectives |language=en |volume=124 |issue=9 |pages=1334–1343 |doi=10.1289/ehp.1409277 |issn=0091-6765 |pmc=5010409 |pmid=27082891|bibcode=2016EnvHP.124.1334R }}</ref>

There is consistent evidence between wildfire smoke and the exacerbation of asthma.<ref name=":14" />

Asthma is one of the most common chronic disease among children in the United States, affecting an estimated 6.2 million children.<ref>{{Cite web |date=19 October 2018 |title=American Lung Association and Asthma Fact sheet |url=http://www.lung.org/lung-health-and-diseases/lung-disease-lookup/asthma/learn-about-asthma/asthma-children-facts-sheet.html |url-status=live |archive-url=https://web.archive.org/web/20151116182804/http://www.lung.org/lung-health-and-diseases/lung-disease-lookup/asthma/learn-about-asthma/asthma-children-facts-sheet.html |archive-date=16 November 2015 |website=American Lung Association}}</ref> Research on asthma risk focuses specifically on the risk of air pollution during the gestational period. Several pathophysiology processes are involved in this. Considerable airway development occurs during the 2nd and 3rd trimesters and continues until 3 years of age.<ref>{{Cite journal |last1=Nishimura |first1=Katherine K. |last2=Galanter |first2=Joshua M. |last3=Roth |first3=Lindsey A. |last4=Oh |first4=Sam S. |last5=Thakur |first5=Neeta |last6=Nguyen |first6=Elizabeth A. |date=August 2013 |title=Early-Life Air Pollution and Asthma Risk in Minority Children. The GALA II and SAGE II Studies |journal=American Journal of Respiratory and Critical Care Medicine |language=en |volume=188 |issue=3 |pages=309–318 |doi=10.1164/rccm.201302-0264oc |issn=1073-449X |pmc=3778732 |pmid=23750510}}</ref> It is hypothesized that exposure to these toxins during this period could have consequential effects, as the epithelium of the lungs during this time could have increased permeability to toxins. Exposure to air pollution during parental and pre-natal stage could induce epigenetic changes which are responsible for the development of asthma.<ref>{{Cite journal |last1=Hsu |first1=Hsiao-Hsien Leon |last2=Chiu |first2=Yueh-Hsiu Mathilda |last3=Coull |first3=Brent A. |last4=Kloog |first4=Itai |last5=Schwartz |first5=Joel |last6=Lee |first6=Alison |date=1 November 2015 |title=Prenatal Particulate Air Pollution and Asthma Onset in Urban Children. Identifying Sensitive Windows and Sex Differences |journal=American Journal of Respiratory and Critical Care Medicine |volume=192 |issue=9 |pages=1052–1059 |doi=10.1164/rccm.201504-0658OC |issn=1535-4970 |pmc=4642201 |pmid=26176842}}</ref> Studies have found significant association between PM<sub>2.5</sub>, NO<sub>2</sub> and development of asthma during childhood despite heterogeneity among studies.<ref>{{Cite journal |last1=Hehua |first1=Zhang |last2=Qing |first2=Chang |last3=Shanyan |first3=Gao |last4=Qijun |first4=Wu |last5=Yuhong |first5=Zhao |date=November 2017 |title=The impact of prenatal exposure to air pollution on childhood wheezing and asthma: A systematic review |journal=Environmental Research |volume=159 |pages=519–530 |bibcode=2017ER....159..519H |doi=10.1016/j.envres.2017.08.038 |issn=0013-9351 |pmid=28888196 |s2cid=22300866}}</ref> Furthermore, maternal exposure to chronic stressors is most likely present in distressed communities, and as this can be correlated with childhood asthma, it may further explain links between early childhood exposure to air pollution, neighborhood poverty, and childhood risk.<ref>{{Cite journal |last1=Morello-Frosch |first1=Rachel |last2=Shenassa |first2=Edmond D. |date=August 2006 |title=The Environmental 'Riskscape' and Social Inequality: Implicationsfor Explaining Maternal and Child Health Disparities |journal=Environmental Health Perspectives |language=en |volume=114 |issue=8 |pages=1150–1153 |doi=10.1289/ehp.8930 |issn=0091-6765 |pmc=1551987 |pmid=16882517}}</ref>