PurpleAir Study Showcase: PurpleAir Sensors Used in Environmental Disparity Study Across US

Topics of increasing interest include environmental disparity and systemic environmental racism. In the study, "Disparate Air Pollution Reductions During California's COVID-19 Economic Shutdown" (Bluhm et al., 2022), PurpleAir sensors were used for data gathering across various minority communities in California.

The study took the opportunity of the economic shutdown during the COVID-19 pandemic and reduced economic and industrial activity to analyze and interpret ground-based air quality data. The research by Richard Bluhm and colleagues aimed to show that sheltering in place produced disproportionate air pollution reductions for non-white people, in which the Hispanic, Asian and low-income communities predominate.

The study aimed to estimate pollution exposure disparities in California. Results suggest racial and ethnic-based disparities in implementing and controlling local and regional pollution mitigation strategies. The research used public and ground-based monitoring for respirable particulate matter, including PurpleAir sensors and satellite records of nitrogen dioxide.

After measuring the air quality before and after the shutdown, the analysis found that reductions in PM2.5 and NO2 emissions associated with transportation and agricultural activity disproportionally affect Latin and Asian communities compared to the wealthier and predominantly white neighborhoods. Notably, members across Latin communities drove more than members in more affluent communities during the shutdown, linked to job nature (e.g., frontline workers), explaining the higher levels of transport emissions.

The research pointed out that although Latin communities reported lower income levels than Asian communities, both communities experienced similar reduction levels. The study authors wrote of "indirect, yet substantial, evidence of systemic racial and ethnic bias in the generation and control of pollution from the portion of the economy most impacted in the early pandemic period." (Bluhm et al., 2022)

However, these findings were not recorded in predominantly Black communities. The pollution burden in these communities may be due to current and historical bias in policy rather than in-person economy, given that there is a relatively lower concentration of Black members within a contained population in California than Latin and Asian people.

The study findings concluded that local factors and the State's other socio-political factors affected the air pollution levels measured by devices like our PurpleAir sensors in Latin and Asian communities.

Source: Disparate air pollution reductions during California's COVID-19 economic shutdown.

*Editor's Note: The PurpleAir blog aims to raise awareness and understanding of pollution-related research that also features PurpleAir data. We share peer-reviewed studies and findings from across academic sectors for our readers' reference only and assume no responsibility for statements and opinions advanced by the authors of the various studies. Please contact us if you have any studies or reports you would like us to showcase.