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Characterizing the spatial distribution of United States Environmental Protection Agency outdoor air quality monitors within historically redlined areas
Citation:
Luben, Tom, A. Wilkie, M. Jimenez, C. Gray, AND K. Rappazzo. Characterizing the spatial distribution of United States Environmental Protection Agency outdoor air quality monitors within historically redlined areas. International Society for Environmental Epidemiology (ISEE) North American Chapter Meeting, Corvallis, OR, June 19 - 21, 2023.
Impact/Purpose:
We aim to characterize the spatial distribution of outdoor ambient air quality monitors within historically redlined areas during three relevant time periods for linking environmental health data.
Description:
Background/Aim: Starting mid-1930s, the Home Owners’ Loan Corporation (HOLC) ranked urban neighborhoods as least to most desirable in terms of perceived mortgage stability based on the racial, ethnic, and religious characteristics of the residents. This racist practice, redlining, led to disparities in proximity to environmental pollutants in these areas. We aim to characterize the spatial distribution of outdoor ambient air quality monitors within historically redlined areas during three relevant time periods for linking environmental health data. Methods: We accessed the United States Environmental Protection Agency’s Air Quality System (AQS) database to determine locations of outdoor air quality monitors within the contiguous US for three different time windows: 1) currently active sites, 2) sites with continuous operation from January 1, 2000 to December 31, 2009, and 3) sites with continuous operation from January 1, 2010 to December 31, 2019. Utilizing Mapping Inequality’s HOLC polygon shapefile, AQS sites were assigned HOLC grades A (Best), B (Still desirable), C (Declining), or D (Hazardous) for the three time periods of interest. Results: There are currently 4,649 active AQS sites within the contiguous US – an increase from 2010-2019 (n=3,803) and 2000-2009 (n=3,042). Among the three time periods evaluated, approximately 8% of AQS sites are located within HOLC areas (any grade) with an increasing proportion of sites located in worsening grade category (e.g., for currently active sites, of the 410 sites located within any HOLC grade, 3.9% are in grade A while 47.3% are in grade D). Conclusions: Relative coverage of operating AQS sites within HOLC grades C and D has increased over time. Publicly available AQS data may be used by concerned citizens, local and state regulatory agencies, and environmental health researchers to further evaluate how an almost 90-year-old racist policy continues to impact environmental exposures and health disparities today.