Table 1

Postneonatal infant mortality rates attributable to PM₁₀ air pollution in selected U.S. metropolitan counties, 1995–97

Health outcome

Effect estimate Relative Risk per 10 μg/m³ PM₁₀ (± 95% Confidence Interval (CI))*

Observed number of deaths per 100,000 infants {and expected reference at 12.0 μg/m³ PM₁₀ annual mean**}

Estimated increment in number of deaths per 10 μg/m³ PM₁₀ and 100,000 infants (lower and upper limits based on ± 95% CI estimates)

Attributable infant mortality between the reference** and the observed mean level (lower and upper limits based on ± 95% CI estimates)

Attributable infant mortality between the reference level** and a mean level of 25.0 μg/m³ PM₁₀*** (lower and upper limits based on ± 95% CI estimates)

Attributable deaths per 100,000 infants

Attributable proportion (%)

Attributable deaths per 100,000 infants

Attributable proportion (%)

All cause mortality

1.04 (1.02–1.07)

236.8 {222.1}

8.9 (4.4–15.5)

14.7 (7.3–25.6)

6 (3–11)

10.9 (5.5–19.1)

5 (2–8)

Sudden infant death syndrome****, normal birth weight

1.12 (1.07–1.17)

73.0 {61.2}

7.3 (4.3–10.4)

11.7 (6.8–16.6)

16 (9–23)

9.0 (5.3–12.8)

12 (7–18)

Respiratory disease mortality*****, normal birth weight

1.20 (1.06–1.36)

9.3 {6.9}

1.4 (0.4–2.5)

2.3 (0.7–4.1)

24 (7–44)

1.8 (0.5–3.2)

19 (6–34)

* From Woodruff and colleagues 1997 [14] ** We estimate cases attributable to PM₁₀ only above a reference level of 12.0 μg/m3 *** Equivalent for new U.S. PM_2.5 standard; the observed mean level was used if below 25.0 μ g/m³ PM₁₀ ****SIDS deaths are defined by the International Classification of Diseases, Revision 9 (ICD9) code 798.0. *****Respiratory deaths are defined by ICD9 codes 460–519.

Kaiser et al. Environmental Health: A Global Access Science Source 2004 3:4   doi:10.1186/1476-069X-3-4