TY - JOUR
T1 - Changes in criteria air pollution levels in the US before, during, and after Covid-19 stay-at-home orders
T2 - Evidence from regulatory monitors
AU - Bekbulat, Bujin
AU - Apte, Joshua S.
AU - Millet, Dylan B.
AU - Robinson, Allen L.
AU - Wells, Kelley C.
AU - Presto, Albert A.
AU - Marshall, Julian
N1 - Publisher Copyright:
© 2020
PY - 2021/5/15
Y1 - 2021/5/15
N2 - The widespread and rapid social and economic changes from Covid-19 response might be expected to dramatically improve air quality. However, national monitoring data from the US Environmental Protection Agency for criteria pollutants (PM2.5, ozone, NO2, CO, PM10) provide inconsistent support for that expectation. Specifically, during stay-at-home orders, average PM2.5 levels were slightly higher (~10% of its multi-year interquartile range [IQR]) than expected; average ozone, NO2, CO, and PM10 levels were slightly lower (~30%, ~20%, ~27%, and ~1% of their IQR, respectively) than expected. The timing of peak anomaly, relative to the stay-at-home orders, varied by pollutant (ozone: 2 weeks before; NO2, CO: 3 weeks after; PM10: 2 weeks after); but, by 5–6 weeks after stay-at-home orders, the concentration anomalies appear to have ended. For PM2.5, ozone, CO, and PM10, no US state had lower-than-expected pollution levels for all weeks during stay-at-home-orders; for NO2, only Arizona had lower-than-expected levels for all weeks during stay-at-home orders. Our findings show that the enormous changes from the Covid-19 response have not lowered PM2.5 levels across the US beyond their normal range of variability; for ozone, NO2, CO, and PM10 concentrations were lowered but the reduction was modest and transient.
AB - The widespread and rapid social and economic changes from Covid-19 response might be expected to dramatically improve air quality. However, national monitoring data from the US Environmental Protection Agency for criteria pollutants (PM2.5, ozone, NO2, CO, PM10) provide inconsistent support for that expectation. Specifically, during stay-at-home orders, average PM2.5 levels were slightly higher (~10% of its multi-year interquartile range [IQR]) than expected; average ozone, NO2, CO, and PM10 levels were slightly lower (~30%, ~20%, ~27%, and ~1% of their IQR, respectively) than expected. The timing of peak anomaly, relative to the stay-at-home orders, varied by pollutant (ozone: 2 weeks before; NO2, CO: 3 weeks after; PM10: 2 weeks after); but, by 5–6 weeks after stay-at-home orders, the concentration anomalies appear to have ended. For PM2.5, ozone, CO, and PM10, no US state had lower-than-expected pollution levels for all weeks during stay-at-home-orders; for NO2, only Arizona had lower-than-expected levels for all weeks during stay-at-home orders. Our findings show that the enormous changes from the Covid-19 response have not lowered PM2.5 levels across the US beyond their normal range of variability; for ozone, NO2, CO, and PM10 concentrations were lowered but the reduction was modest and transient.
KW - Air pollution and Covid-19
KW - Air pollution and stay-at-home orders
KW - COVID-19
KW - Criteria air pollution
KW - Stay-at-home orders
UR - http://www.scopus.com/inward/record.url?scp=85099710171&partnerID=8YFLogxK
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U2 - 10.1016/j.scitotenv.2020.144693
DO - 10.1016/j.scitotenv.2020.144693
M3 - Article
C2 - 33736238
AN - SCOPUS:85099710171
SN - 0048-9697
VL - 769
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 144693
ER -
