Summary of time series studies relating fine and coarse particulate matter to hospital admissions
| Ref | Study area | Approximate number of events | Measurement of coarse particles | Correlation coarse–fine | % increase per 10 μg·m−3 95% CI | Estimates from two-pollutant model |
| 26 | Toronto, Canada | 1700 respiratory admissions | Direct | 0.72 | FP was significant in the single pollutant model | NA |
| 27 | Toronto, Canada | 16500 cardiac admissions | Direct | 0.72 | Cardiac FP 2.8 (−0.3–5.9) | NA |
| CP 7.6 (3.2–11.9) | ||||||
| 9200 respiratory admissions | Respiratory FP 3.4 (1.4–5.4) | |||||
| CP 4.8 (2.1–7.6) | ||||||
| 28, 38 | Seattle, USA | 7800 asthma admissions | Indirect | 0.43 | FP 3.4 (0.8–5.1) | NA |
| CP 2.2 (0.0–5.4) | ||||||
| 29 | Toronto, Canada | 130000 (for the most frequent) | Direct | 0.47 | IHD:FP 3.2 (2.2–4.2) | CP significant for asthma and COPD, FP significant for respiratory infections and dysrhythmias |
| CP 1.5 (0.5–2.4) | ||||||
| IHD admissions | Resp infections: FP 4.2 (2.9–5.6) | Never both significant | ||||
| CP 3.6 (1.9–5.4) | ||||||
| Asthma:FP 2.6 (1.0–4.1) | ||||||
| CP 4.3 (2.3–6.3) | ||||||
| 36 | Santiago, Chile | 61000 respiratory emergency visits in children aged <15 yrs | Indirect | 0.84 (cold) 0.61 (warm) | Cold season | NA |
| FP 0.6 (0.2–1.0) | ||||||
| CP 0.5 (0.0–0.9) | ||||||
| Warm season | ||||||
| FP 0.4 (−0.6–1.5) | ||||||
| CP 1.2 (0.1–2.4) | ||||||
| 37 | Atlanta, USA | 28000 CVD emergency visits | Direct | 0.43 | FP 3.3 (1.0–5.6) | NA |
| CP 1.2 (−1.5–4.0) | ||||||
| 16, 17 | Detroit, USA | Unknown number of hospital admissions in elderly | Indirect | 0.42 | Pneumonia | In two-pollutant model FP had a larger positive coefficient for pneumonia, heart failure and IHD, while CP had a large positive coefficient for COPD |
| FP 4.1 (0.6–8.1) | ||||||
| CP 4.5 (0.0–9.4) | ||||||
| COPD:FP 0.1 (−3.9–4.5) | ||||||
| CP 4.3 (−1.3–10.5) | ||||||
| IHD:FP 1.2 (−1.1–3.6) | ||||||
| CP 3.3 (0.2–8.5) | ||||||
| Heart failure | ||||||
| FP 2.8 (0.1–5.7) | ||||||
| CP 2.0 (−1.5–5.6) | ||||||
| 30 | Los Angeles county, USA | 11000 hospital admissions for COPD | Indirect | COPD aged >65 yrs | NA | |
| FP 2.0 (0.4–3.6) | ||||||
| CP 2.0 (−0.2–4.2) | ||||||
| COPD aged 20–64 yrs | ||||||
| FP 1.7 (0.1–3.3) | ||||||
| CP 2.4 (−0.1–4.9) | ||||||
| COPD aged 0–19 yrs | ||||||
| FP 0.6 (−1.8–3.0) | ||||||
| CP 6.6 (3.2–10.0) | ||||||
| 13 | West Midlands conurbation, UK | 47000 CVD admissions | Indirect | 0.34 | CVD:FP −0.3 (−1.5–0.9) | NA |
| CP −0.6 (−3.3–11.9) | ||||||
| 44000 respiratory admissions | Resp:FP 0.7 (−0.5–1.4) | |||||
| CP 0.2 (−2.2–2.7) | ||||||
| 31 | Toronto, Canada | 16000 respiratory hospital admissions in children aged <2 yrs | Direct | FP 8.8 (3.5–14.0) | NA | |
| CP 11.3 (5.4–17.2) | ||||||
| 32 | Toronto, Canada | 7300 asthma admissions in children aged 6–12 yrs | Direct | 0.44 | Young males | NA |
| FP −4.3 (−10.8–1.1) | ||||||
| CP 11.8 (3.6–21.3) | ||||||
| Young females | ||||||
| FP 5.4 (−3.2–12.9) | ||||||
| CP 21.3 (9.5–35.5) | ||||||
| 34 | Vancouver, Canada | 4400 hospital admission for COPD | Indirect | Moderate | FP 19.8 (4.0–36.5) | FP 15.5 (−0.2–34.3) |
| CP 21.2 (6.0–37.6) | CP 15.9 (−0.1–32.6) | |||||
| 35 | Spokane, USA | 29000 respiratory emergency visits | Indirect | 0.31 | FP 2.0 (−1.0–5.0) | NA |
| CP 0.8 (−0.4–2.0) | ||||||
| 33 | Atlanta, USA | 27000 CVD emergency visits | Direct | 0.43 | FP 3.3 (1.0–5.6) | NA |
| CP 2.4 (−3.0–8.0) |
95% CI: 95% confidence interval; IHD: ischaemic heart disease; CVD: cardiovascular disease; COPD: chronic obstructive pulmonary disease; FP: fine particles; CP: coarse particles; Resp: respiratory; NA: not applicable.