Concurrent Heat and Air Pollution Exposures among People Experiencing Homelessness

Abstract

Background: Extreme heat and air pollution are important human health concerns; exposure can affect mental and physical well-being, particularly during periods of co-occurrence. Yet, the impacts on people are largely determined by underlying health conditions, coupled with the length and intensity of exposure. Preexisting adverse health conditions and prolonged exposure times are more common for people experiencing homelessness, particularly those with intersectional identity characteristics (e.g., disease, ability, age, etc.). Partially due to methodological limitations, such as data scarcity, there is a lack of research at the intersection of this at-risk population within the climate-health domain.

Objectives: We have three distinct objectives throughout this article: a) to advance critical discussions around the state of concurrent high heat and air pollution exposure research as it relates to people experiencing homelessness; b) to assert the importance of heat and air pollution exposure research among a highly vulnerable, too-often homogenized population-people experiencing homelessness; and c) to underline challenges in this area of study while presenting potential ways to address such shortcomings.

Discussion: The health insights from concurrent air pollution and heat exposure studies are consequential when studying unhoused communities who are already overexposed to harmful environmental conditions. Without holistic data sets and more advanced methods to study concurrent exposures, appropriate and targeted prevention and intervention strategies cannot be developed to protect this at-risk population. We highlight that a) concurrent high heat and air pollution exposure research among people experiencing homelessness is significantly underdeveloped considering the pressing human health implications; b) the severity of physiological responses elicited by high heat and air pollution are predicated on exposure intensity and time, and thus people without means of seeking climate-controlled shelter are most at risk; and c) collaboration among transdisciplinary teams is needed to resolve data resolution issues and enable targeted prevention and intervention strategies. https://doi.org/10.1289/EHP13402.

Figure 1.

Climate drivers of heat and air pollution. Social and environmental factors play a substantial role in moderating health outcomes related to high temperatures and elevated levels of air pollution by increasing the amount of time an individual is exposed. The overlapping Venn diagram illustrates how social factors influence the ability of an individual to secure housing, whereas environmental factors determine the quality of such housing; the intersection of housing security and quality mediates environmental exposure pathways.

Figure 2.

Heat and air pollution exposure as a function of housing status. The diagram illustrates how access to mediating factors (i.e., resources to help an individual cope with environmental hazards) differs based on housing status, impacting environmental exposures (such as heat and air pollution). The solid line denotes the assumption of decreasing access to mediary factors as housing status destabilizes. The dashed, curved lines depict the multitude of lived actualities when considering the role of intersectional identity characteristics (e.g., race, sex, income, disease, etc.) that coexist with housing status to create lived experiences.