Decreased air quality shows minimal influence on peak summer attendance at forested Pacific West national parks

"To assess visitation response to diminished air quality, we utilized wildfire-generated particulate matter (PM2.5) data in conjunction with monthly attendance records for three ecoregions containing eight national parks in Washington, Oregon, and California from 2009-2019. We analyzed daily PM2.5 levels from data gridded at the 10km scale for National Park Service units by Level III forest ecoregions within the National Park Service's Pacific West Unit. Data were then compared to normalized monthly visitation trends for each of the ecoregions using two statistical methods Kendall’s Tau and Analysis of Variance (ANOVA) with post-hoc Tukey tests. Results demonstrate that attendance at these national parks does not decrease in response to increased PM2.5 levels. Instead, we see several statistically significant increases in attendance across these ecoregions during periods of reduced air quality. Of 115 shifts between air quality categories during the busy season of July to September, there are no significant decreases in attendance as air quality worsens. "

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Parent dataset from
Childs, M. L., Li, J., Wen, J., Heft-Neal, S., Driscoll, A., Wang, S., Gould, C. F.,
Qiu, M., Burney, J., & Burke, M. (2022). Daily Local-Level Estimates of Ambient Wildfire Smoke PM 2.5 for the Contiguous US. Environmental Science & Technology, 56(19), 13607–13621. https://doi.org/10.1021/acs.est.2c02934