TABLE 1.
Meta-analysis results and characteristics of studies informing the associations between long-term exposure to nitrogen dioxide (NO2) (per 10 μg/m3 increase) and mortality outcomes (Global, 2023-2024).
| N | Pooled RR (95% CI) | I2 (%) | 80% prediction interval | Sample size | Age (years) | Median of NO2 (min – max) | |
|---|---|---|---|---|---|---|---|
| All-cause | 34 | 1.05 (1.03, 1.07) | 95 | (0.98, 1.12) | 130,487,512 | >15 | 25.0 (7.1—129.9) |
| Circulatory disease | 28 | 1.05 (1.03, 1.08) | 97 | (0.97, 1.15) | 104,984,429 | >15 | 26.7 (7.1—104) |
| IHD | 20 | 1.05 (1.03, 1.08) | 95 | (0.99, 1.12) | 96,725,244 | >15 | 26.7 (7.6—104) |
| Cerebrovascular disease | 20 | 1.08 (0.99, 1.19) | 98 | (0.82, 1.43) | 96,394,524 | >25 | 26.0 (7.6—104) |
| Respiratory disease | 25 | 1.05 (1.03, 1.07) | 90 | (0.99, 1.11) | 106,631,530 | >15 | 25.0 (7.1—129.9) |
| COPD | 15 | 1.04 (1.02, 1.06) | 62 | (0.99, 1.09) | 83,982,574 | >15 | 25.7 (20.5—104) |
| ALRI | 9 | 1.08 (1.04, 1.12) | 92 | (1.00, 1.16) | 52,302,628 | >30 | 25.0 (50.5—104) |
| Lung cancer | 20 | 1.07 (1.04, 1.10) | 92 | (0.99. 1.14) | 102,667,742 | >15 | 28.9 (7.6—129.9) |
a
N = number of studies Note: Only Hart et al [35] included population above 15 years old-all other studies include adults ≥18 years old, with the majority ≥30 years old.