Table 2:

Association between air pollution and hospital admission for myocardial infarction with increases in the interquartile range of pollutants during various referent time intervals in regions with differing nitrogen dioxide pollution levels

Pollutant (median with IQR)Lag (days)OR* (95% CI)
Entire study population (citywide NO2)
n = 6142		Low NO2 tertile
n = 1660		Medium NO2 tertile
n = 3088		High NO2 tertile†
n = 1384
CO (0.35, IQR 0.27–0.47)0 index day0.97 (0.93–1.02)0.94 (0.88–1.01)0.97 (0.92–1.02)1.02 (0.95–1.09)
1-day lag1.03 (0.98–1.08)0.98 (0.92–1.05)1.02 (0.97–1.07)1.10 (1.02–1.18)
2-day lag1.01 (0.96–1.06)1.03 (0.96–1.10)0.99 (0.94–1.04)1.04 (0.97–1.12)
0- to 2-day average1.01 (0.94–1.08)0.97 (0.88–1.06)0.99 (0.92–1.05)1.09 (0.99–1.21)
0- to 4-day average0.97 (0.90–1.05)0.92 (0.83–1.03)0.96 (0.88–1.03)1.08 (0.96–1.21)
NO2 (18.22, IQR 12.67–25.00)0 index day1.00 (0.94–1.07)0.97 (0.89–1.06)1.01 (0.95–1.08)1.05 (0.95–1.15)
1-day lag1.04 (0.97–1.11)1.00 (0.91–1.09)1.01 (0.94–1.07)1.16 (1.05–1.28)†
2-day lag1.03 (0.97–1.10)1.03 (0.94–1.12)1.00 (0.93–1.06)1.11 (1.01–1.22)
0- to 2-day average1.05 (0.96–1.14)1.00 (0.88–1.12)1.01 (0.92–1.10)1.20 (1.05–1.36)
0- to 4-day average0.98 (0.88–1.08)0.90 (0.78–1.04)0.93 (0.84–1.03)1.20 (1.03–1.40)†
O3 max (39.00, IQR 32.00–47.00)0 index day1.00 (0.95–1.06)1.02 (0.96–1.10)0.98 (0.93–1.03)1.03 (0.96–1.11)
1-day lag0.99 (0.94–1.04)0.96 (0.90–1.03)0.97 (0.93–1.03)1.07 (0.99–1.15)
2-day lag0.99 (0.94–1.04)0.97 (0.91–1.04)0.99 (0.94–1.04)1.02 (0.94–1.10)
0- to 2-day average0.99 (0.93–1.06)0.98 (0.90–1.07)0.97 (0.91–1.03)1.06 (0.96–1.17)
0- to 4-day average1.00 (0.93–1.08)1.00 (0.90–1.11)0.97 (0.90–1.04)1.09 (0.97–1.22)
SO2 (1.00, IQR 1.00–2.00)0 index day1.00 (0.96–1.05)1.00 (0.95–1.06)0.97 (0.93–1.01)1.08 (1.02–1.15)†
1-day lag1.05 (1.01–1.09)1.03 (0.98–1.09)1.04 (1.00–1.08)1.10 (1.03–1.16)
2-day lag1.04 (0.99–1.08)1.04 (0.98–1.10)1.03 (0.99–1.07)1.05 (0.99–1.12)
0- to 2-day average1.06 (1.00–1.12)1.05 (0.97–1.14)1.03 (0.97–1.09)1.15 (1.06–1.25)
0- to 4-day average1.05 (0.98–1.12)1.05 (0.96–1.16)1.02 (0.95–1.09)1.10 (0.99–1.22)
PM10 20.00, IQR 14.00–30.00)0 index day0.98 (0.95–1.02)0.95 (0.90–1.00)0.98 (0.95–1.02)1.03 (0.97–1.08)
1-day lag1.01 (0.97–1.05)0.97 (0.92–1.02)1.01 (0.97–1.04)1.06 (1.01–1.12)†
2-day lag1.01 (0.98–1.05)0.99 (0.95–1.04)1.00 (0.96–1.04)1.06 (1.00–1.12)
0- to 2-day average1.00 (0.96–1.05)0.95 (0.89–1.01)0.99 (0.95–1.04)1.08 (1.01–1.16)†
0- to 4-day average0.99 (0.94–1.05)0.95 (0.88–1.02)0.98 (0.93–1.04)1.07 (0.99–1.15)
PM2.5 (7.00, IQR 4.33–10.50)0 index day1.01 (0.98–1.05)0.99 (0.94–1.05)1.00 (0.97–1.04)1.06 (1.00–1.11)
1-day lag1.02 (0.99–1.06)0.98 (0.93–1.03)1.04 (1.01–1.08)1.04 (0.99–1.10)
2-day lag1.00 (0.96–1.04)0.96 (0.90–1.01)1.02 (0.97–1.06)1.03 (0.98–1.08)
0- to 2-day average1.02 (0.97–1.07)0.96 (0.90–1.03)1.03 (0.98–1.08)1.07 (1.00–1.13)
0- to 4-day average1.02 (0.97–1.08)0.98 (0.91–1.06)1.04 (0.99–1.10)1.04 (0.96–1.12)
AQHI (4.01, IQR 3.49–4.65)0 index day1.01 (0.96–1.05)1.00 (0.94–1.06)0.99 (0.95–1.04)1.06 (0.99–1.13)
1-day lag1.02 (0.97–1.07)0.97 (0.91–1.03)1.00 (0.96–1.05)1.12 (1.05–1.20)†
2-day lag1.01 (0.97–1.06)0.99 (0.93–1.05)1.00 (0.95–1.04)1.07 (1.00–1.14)
0- to 2-day average1.02 (0.96–1.08)0.98 (0.90–1.06)1.00 (0.94–1.05)1.13 (1.04–1.23)†
0- to 4-day average1.01 (0.94–1.08)0.97 (0.89–1.07)0.97 (0.91–1.04)1.13 (1.02–1.24)†

  • Note: CI = confidence interval, CO = carbon monoxide, IQR = interquartile range, NO2 = nitrogen dioxide, OR = odds ratio, O3 = ozone, PM10 = particulate matter < 10 μm in diameter, PM2.5 = particulate matter < 2.5 μm in diameter, SO2 = sulfur dioxide.

  • * Odds ratios are adjusted for temperature and relative humidity.

  • ↵† Significant difference comparing OR in the highest NO2 tertile to the lowest NO2 tertile using the Cochran Q test.

  • Significant associations are bolded.