Table E3.
Controlled interrupted time series regression analysis results for 4 criteria air pollutants
| Variables | PM2.5 |
Ozone |
PM10 |
NO2 |
||
|---|---|---|---|---|---|---|
| AirNow | AirData | AirNow | AirData | AirData | AirData | |
| Days (P value) | −0.03 (.064) | −0.05 (.002) | 0.26 (<.0001) | 0.27 (<.0001) | −0.044 (.23) | −0.07 (.04) |
| Year 2020 (P value) | −3.51 (.0005) | −3.58 (.0002) | 2.18 (.25) | 1.16 (.54) | −5.40 (.004) | −0.77 (.66) |
| Covid_restrictions (P value) | −5.25 (.009) | −4.56 (.019) | 16.08 (<.0001) | 12.90 (.0007) | −0.52 (.88) | −0.33 (.92) |
| Days × Year 2020 (P value) | 0.0009 (.97) | 0.02 (.41) | −0.03 (.52) | −0.04 (.42) | −0.005 (.92) | −0.01 (.70) |
| Days × Covid_restrictions (P value) | 0.045 (.10) | 0.05 (.04) | −0.24 (<.0001) | −0.2 (<.0001) | 0.006 (.90) | −0.001 (.98) |
| Year 2020 × Covid_restrictions (P value) | 2.24 (.42) | 1.56 (.56) | −6.56 (.21) | −3.48 (.51) | −7.57 (.15) | −5.5 (.26) |
| Days × Year 2020 × Covid_restrictions (P value) | −0.005 (.88) | −0.01 (.66) | 0.09 (.2) | 0.05 (.44) | 0.08 (.27) | 0.05 (.41) |
Outcome was levels of each pollutant. Independent variables included days, referring to the 120 d between January 17 and May 17; year 2020, indicating whether it was the year 2020 or historical time period; covid_restrictions, indicating whether the measure was from before or after March 17. Each column corresponds to 1 model with indicated outcome variable and source of historical measures (AirNow or AirData). Terms in the model are indicated in each row. Values are coefficient estimate (P value).