Case Study

In mid-September 2020, wildfires from California and southern Oregon shrouded Portland, Oregon in smoke, obscuring the horizons and registering “hazardous” levels of particulate matter less than 2.5 micrometers (PM2.5) on the Environmental Protection Agency’s Air Quality Index (AQI). Just days after Portland registered the worst measured AQI in the world on September 13, I called my patient “Paul” for an urgent care appointment. That week our clinic had emergently transitioned to telemedicine as these air quality conditions are dangerous even to healthy, immunocompetent adults. Paul, a relatively healthy, never smoker, 40-year-old man was experiencing a cough productive of black sputum and pleuritic chest pain, relieved intermittently by an albuterol inhaler. Like many adults seen at our clinic, he stayed in a community shelter only open for the night. He spent most of the day outside, walking nine miles roundtrip to a public library to find refuge from the smoke. He could not afford public transportation due to coronavirus-related job loss. Without an indication for hospital admission, we could not provide the treatment he most needed—respite from the inciting smoke. Ultimately, he was diagnosed with mild persistent asthma that improved with the addition of daily inhaled corticosteroids, allergy medications, transit assistance, and the marked improvement of the local air quality.


As the incidence of climate-related emergencies continues to rise, we expect to see more patients like Paul, about whom we have an alarming paucity of baseline data. While populations who are homeless may represent a minority of patients, the climate-related health issues affecting them foreshadow effects on the elderly and those with chronic disease, and, eventually, the general public. Paul is a “canary in the coal mine” of a warming earth, exposed to extreme weather events. We have an ethical obligation to our vulnerable populations and to the future of general public health to better understand and effectively mitigate the human health effects of climate change.

The association between particulate matter air pollution and pulmonary disease has been well documented, and wildfires contribute a significant amount of particulate matter that worsens pulmonary disease.1 A study of the Rice Ridge fire in Seeley Lake, Montana, in September 2017 demonstrated resident participants who experienced only 35 days of “very unhealthy” air quality and nine days of “hazardous” had clinically significant reduction in FEV1/FVC ratios with sustained reduction in lung function at two years.2 These participants were presumably housed and were reported to have an average household income between $30,000-$75,000. There is a lack of similar data on our unsheltered neighbors—despite 945,000 articles under the Medical Subject Heading (MeSH) “Lung Diseases” on PubMed (January 14, 2021), only 292 relate to “Homeless Persons” and none of them also consider “Climate Change.”

Our Federally Qualified Health Center (FQHC) in Portland, Oregon, cares for more than 5,000 men and women with housing instability of whom more than 1,600 (33%) have a chronic pulmonary disease, including 769 patients with COPD and 789 patients with asthma, as of December 2020. Our patients represent the majority of the 4,015 people in Portland who met the Housing and Urban Development’s definition of homelessness during the biennial Point-In-Time (PIT) count on January 23, 2019:3 2,037 people who were unsheltered, 1,459 people in emergency shelters, and 519 people in transitional housing. Additionally, the PIT count documented an increase in individuals of color, severely disabled, and those who are chronically unsheltered in this population, emphasizing exacerbation of disparities. There is concern that the PIT count may not even be possible this year due to the risks of the persisting COVID-19 pandemic which will hinder not only evaluation of the homeless crisis, but also access to federal resources based on documented need.4


With this, we ask physician leaders of the healthcare, scientific, and health policy communities to take ownership of addressing the disparities in those who are most vulnerable to the impending climate emergencies. This is underpinned by medical, ethical, and economic necessity. The following three actions physicians must take immediately:

  1. Advocate diligently in our communities for development of year-round, 24-hour weather refuge for people who are unsheltered. Additionally, partner clinics and hospitals with community resources, such as shelters or hotels, to provide access to necessary medical respite for patients who are unsheltered and ill or in need of time to convalesce following hospitalization.
  2. Lead dialogues in our communities between local officials, key stakeholders, allies, and those who are unsheltered to better determine existing resources and outstanding needs. The needs of each community will depend upon the environment and culture and will necessitate unique approaches that can only be determined at the local level.
  3. Document the disproportionate climate-fueled suffering of our populations who are unsheltered, through dedicated research, policy creation, and narrative publication. Climate change is creating a multitude of new health problems that will challenge existing knowledge and infrastructure, and as physicians we must be astute observers to these changes so that we may advocate for the needs of our communities.

Climate change in no longer a theoretical risk—its manifestations are now in our clinics and hospitals, and as physicians we have been the first to see them. We can expect to see more people like Paul showing up in our emergency rooms in respiratory distress as the days with extraordinary air pollution increase. While it remains to be seen if we are past the point of effectively mitigating climate change itself, physicians must be prepared to document, report, and research health effects to help communities prepare for increases in the climate-related health emergencies to come.


  1. Cromar K, Gladson L, Ghazipura M, et al. Estimated excess morbidity and mortality associated with air pollution above American Thoracic Society-recommended Standards, 2013-2015. American Thoracic Society and Marron Institute Report. Ann Am Thorac Soc. 2017; 15(5) 542-551.
  2. Fessler P. For many areas, count of homeless population is canceled, or delayed. NPR. Broadcast January 18, 2021. Accessed February 15, 2021.
  3. Regional Research Institute. 2019 point-in-time count of homelessness in Portland/Gresham/Multnomah County, Oregon. Published April 30, 2019. Accessed February 15, 2021.
  4. Orr A, Migliaccio C, Buford M, et al. Sustained effects on lung function in community members following exposure to hazardous PM2.5 levels from wildfire smoke. Toxics. 2020, 8(3), 53;



Advocacy, Health Equity, Medical Ethics, SGIM, Social Determinants of Health, Vulnerable Populations

Author Descriptions

Dr. Rutlen ( and Dr. Green ( are second-year residents in the Department of Medicine at Oregon Health & Science University and Old Town Clinic.