Pollutant | Mean | IQR | All seasons | Season | ||||
---|---|---|---|---|---|---|---|---|
 |  |  |  |  | October to March | April to September | ||
 |  |  | OR | 95% C.I. | OR | 95% C.I. | OR | 95% C.I. |
SO2 | Same day | 3.0 | 0.96 | 0.93–0.98 | 0.93 | 0.90–0.97 | 0.98 | 0.94–1.02 |
 | 1-day lag |  | 0.98 | 0.96–1.01 | 0.95 | 0.92–0.98 | 1.02 | 0.98–1.06 |
 | 3-day average |  | 0.95 | 0.91–0.98 | 0.90 | 0.86–0.95 | 1.00 | 0.94–1.06 |
 | 5-day average |  | 0.93 | 0.89–0.97 | 0.88 | 0.83–0.93 | 1.01 | 0.94–1.08 |
NO2 | Same day | 13.5 | 0.98 | 0.96–1.01 | 0.96 | 0.93–1.00 | 1.04 | 0.99–1.09 |
 | 1-day lag |  | 0.99 | 0.97–1.02 | 0.97 | 0.94–1.01 | 1.04 | 0.99–1.09 |
 | 3-day average |  | 0.98 | 0.95–1.02 | 0.95 | 0.91–0.99 | 1.07 | 1.00–1.14 |
 | 5-day average |  | 0.98 | 0.95–1.02 | 0.94 | 0.90–0.99 | 1.10 | 1.02–1.19 |
CO | Same day | 0.5 | 0.99 | 0.97–1.01 | 0.97 | 0.95–1.00 | 1.09 | 1.03–1.14 |
 | 1-day lag |  | 1.00 | 0.98–1.02 | 0.99 | 0.97–1.01 | 1.04 | 0.99–1.10 |
 | 3-day average |  | 0.99 | 0.97–1.02 | 0.97 | 0.94–1.00 | 1.14 | 1.06–1.23 |
 | 5-day average |  | 1.00 | 0.97–1.03 | 0.97 | 0.94–1.00 | 1.20 | 1.10–1.31 |
O3 (Max) | Same day | 18.0 | 1.03 | 1.00–1.07 | 1.04 | 0.99–1.09 | 1.05 | 1.00–1.10 |
 | 1-day lag |  | 1.04 | 1.01–1.07 | 1.03 | 0.98–1.08 | 1.07 | 1.03–1.12 |
 | 3-day average |  | 1.07 | 1.03–1.12 | 1.06 | 0.99–1.14 | 1.11 | 1.05–1.18 |
 | 5-day average |  | 1.08 | 1.03–1.13 | 1.09 | 1.01–1.17 | 1.11 | 1.04–1.18 |
PM2.5 ‡ | Same day | 6.3 | 1.04 | 1.02–1.06 | 0.99 | 0.95–1.03 | 1.07 | 1.04–1.10 |
 | 1-day lag |  | 1.00 | 0.98–1.02 | 0.99 | 0.95–1.03 | 1.01 | 0.98–1.04 |
 | 3-day average |  | 1.02 | 0.99–1.05 | 0.98 | 0.93–1.03 | 1.06 | 1.02–1.10 |
 | 5-day average |  | 1.01 | 0.97–1.04 | 0.96 | 0.90–1.02 | 1.05 | 1.00–1.10 |
PM10 ‡ | Same day | 16.0 | 1.02 | 0.99–1.05 | 0.99 | 0.95–1.03 | 1.05 | 1.02–1.09 |
 | 1-day lag |  | 1.01 | 0.98–1.03 | 1.02 | 0.98–1.07 | 1.00 | 0.96–1.03 |
 | 3-day average |  | 1.02 | 0.99–1.05 | 1.01 | 0.96–1.06 | 1.03 | 0.99–1.08 |
 | 5-day average |  | 1.00 | 0.97–1.04 | 0.99 | 0.94–1.05 | 1.02 | 0.97–1.07 |