Random-effects summary estimates (as percentage change (95% CIs)) for mortality or hospital admissions associated with a 10 µg/m3 increase in air pollution
| All SC/MC* | Selected SC/MC (cities)† | 1 hour NO2 | 24-hour PM | |||
|---|---|---|---|---|---|---|
| Single-pollutant | Adjusted for PM | Single-pollutant | Adjusted for NO2 | |||
| All-cause mortality, all ages | ||||||
| PM10 | 2/1 | 2/1 (32) | 0.22 (−0.15 to 0.60) | 0.10 (−0.40 to 0.61) | 0.52 (0.29 to 0.75) | 0.48 (0.31 to 0.66) |
| BS | 0/2 | 0/1 (30) | 0.30 (0.22 to 0.38) | 0.33 (0.23 to 0.43) | 0.60 (0.30 to 0.90) | 0.26 (0.00 to 0.52) |
| Visibility | 0/1 | 0/1 (4) | 0.63 (0.21 to 1.05) | 0.52 (0.05 to 1.00) | 35.70 (3.97 to 77.12)‡ | 10.24 (−20.03 to 51.97)‡ |
| All cardiovascular mortality, all ages | ||||||
| PM10 | 1/1 | 0/1 (29) | 0.40 (0.29 to 0.51) | 0.35 (0.21 to 0.49) | 0.76 (0.47 to 1.05) | 0.32 (0.05 to 0.59) |
| BS | 1/1 | 0/1 (29) | 0.40 (0.29 to 0.51) | 0.44 (0.31 to 0.57) | 0.62 (0.35 to 0.90) | 0.17 (−0.10 to 0.44) |
| All respiratory mortality, all ages | ||||||
| PM10 | 0/1 | 0/1 (29) | 0.38 (0.17 to 0.59) | 0.37 (0.08 to 0.66) | 0.71 (0.22 to 1.20) | 0.20 (−0.29 to 0.69) |
| BS | 0/1 | 0/1 (29) | 0.38 (0.17 to 0.59) | 0.26 (−0.12 to 0.64) | 0.84 (0.11 to 1.58) | 0.57 (−0.34 to 1.48) |
| All respiratory hospital admissions, children (<5 years) | ||||||
| PM10 | 1/1 | 1/1 (6) | 0.77 (−0.59 to 2.15) | 0.13 (−0.09 to 0.35) | – | – |
| PM2.5 | 0/1 | 0/1 (4) | 1.62 (0.41 to 2.84) | 4.85 (0.41 to 9.50) | – | – |
| All respiratory hospital admissions, elderly (65+years) | ||||||
| Visibility | 0/1 | 0/1 (4) | 1.42 (0.79 to 2.06) | 1.21 (0.47 to 1.95) | – | – |
| Cardiac hospital admissions, elderly | ||||||
| Visibility | 0/1 | 0/1 (4) | 1.21 (0.84 to 1.58) | 0.73 (0.31 to 1.16) | – | – |
*Numbers of available pairs of single-city (SC)/multi-city (MC) estimates from all studies.
†Numbers of pairs of pooled (from single-city estimates) and multicity estimates used to calculate the overall summary estimate across WHO regions. Estimates were selected for meta-analysis from all those available. The number of cities represented by the summary estimates is given in brackets.
‡The results for visibility (measured as black suspended particles (10−4/m)) are not comparable to other PM results.
BS, Black Smoke; NO2, nitrogen dioxide; PM, particulate matter.