Clearing the Air: How Tree Canopy Coverage Shapes Health Gaps in California

In a recent study comparing residential green cover and direct healthcare costs, it was found that individuals with the highest amount of canopy cover had healthcare costs that were "$374.04 per person per year less than individuals living in the bottom or least green decile" (Van Den Eeden, et al., 2022).This is because trees serve as a natural filter for harmful air pollutants that have negative health effects.Historically, however, communities of color have been excluded from green infrastructure because of restricted access to urban resources.Hence, this project will broadly examine: what is the effect of tree canopy coverage on public health?And specifically, how did tree canopy coverage in California counties affect rates of asthma burden in 2021, and how do these effects differ between counties with majority people of color (POC) populations and those without?To answer this question, I examine the relationship between tree canopy cover and asthma burden across 52 California counties in 2021, comparing specifically between counties with more than 50% of the population as POC and those with less than 50%.I find that tree canopy cover and asthma burden have a moderate negative relationship, and the effects are, in fact, more pronounced in communities of color.I conclude with a discussion of the implications of these findings on urban planning and green infrastructure.