Summary of time-series studies of daily mortality or hospital admissions and NO2 adjusted for PM
| Total | Multicity study | Single-city study | ||||
|---|---|---|---|---|---|---|
| Outcome | Mortality | Hospital admissions | Mortality | Hospital admissions | Mortality | Hospital admissions |
| Total | 36 | 24 | 9 | 4 | 27 | 20 |
| NO2+PM* | ||||||
| PM10 | 23 | 17 | 6 | 2 | 17 | 15 |
| PM2.5 | 7 | 1 | 3 | 1 | 4 | 0 |
| PM10–2.5 | 4 | 0 | 3 | 0 | 1 | 0 |
| BS | 5 | 4 | 3 | 2 | 2 | 2 |
| PNC | 3 | 1 | 0 | 0 | 3 | 1 |
| Carbon | 0 | 0 | 0 | 0 | 0 | 0 |
| TSP | 4 | 2 | 0 | 1 | 4 | 1 |
| Visibility | 2 | 1 | 2 | 1 | 0 | 0 |
| >1 PM metric | 0 | 1 | 0 | 0 | 0 | 1 |
| Disease† | ||||||
| All-cause | 27 | 1 | 7 | 0 | 20 | 1 |
| Cardiovascular | 17 | 11 | 4 | 2 | 13 | 9 |
| Respiratory | 7 | 17 | 3 | 3 | 4 | 14 |
| WHO region‡ | ||||||
| American A | 8 | 4 | 3 | 0 | 5 | 4 |
| European A | 9 | 12 | 3 | 2 | 6 | 10 |
| Western Pacific B | 14 | 5 | 2 | 0 | 12 | 5 |
| American B | 4 | 2 | 0 | 0 | 4 | 2 |
| Western Pacific A | 1 | 2 | 1 | 2 | 0 | 0 |
| South East Asia B | 2 | 0 | 2 | 0 | 0 | 0 |
| Averaging time | ||||||
| 24 hour | 29 | 21 | 6 | 3 | 23 | 18 |
| Maximum 1 hour | 7 | 5 | 3 | 2 | 4 | 3 |
*The eight categories of PM metrics listed in the table above have been generated by grouping different measures of particles. PM10 and PM2.5 refer to the mass per cubic metre of particles of generally <10 μm and 2.5 μm diameter, respectively, in the ambient air.
†Respiratory includes all-respiratory diseases, asthma, COPD, COPD including asthma, lower respiratory infections and upper respiratory diseases; Cardiovascular includes all-cardiovascular diseases, cardiac disease, heart failure, ischaemic heart disease, dysrhythmia and stroke.
‡WHO regions: (A) very low child and adult mortality; (B) low child mortality and low adult mortality; (C) low child mortality and high adult mortality; (D) high child mortality and high adult mortality.
BS, Black Smoke; COPD, chronic obstructive pulmonary disease; PM, particulate matter; PNC, particle number concentration; TSP, total suspended particles.