Table 2.2: Summary of epidemiological studies for carbon monoxide

Mortality

11 Canadian cities

24-hour average

1.2

2.5% (all-cause mortality)

Burnett et al, 1998

Hospital admissions

Seattle, Washington, DC, 1987-94

1-hour maximum,
3-day lag

2.2

6% (95% CI: 3-9%) per 1.2 mg/m³ (asthma admissions - non-elderly)

Sheppard et al, 1999

Reno Nevada, 1989-94

1-hour maximum

3.9

1.5% per 1 mg/m³ (cardiovascular disease - elderly)

3.5% (ischaemic heart disease - elderly)

Yang et al, 1998

Tuscon, Arizona, (1988-90)

1-hour maximum

4.2

2.8% (95% CI: 0.5-5.4%) per 2.1 mg/m³ (cardiovascular disease - elderly)

Schwartz, 1997

Eight US counties 1988-90

1-hour maximum

2.5-5.9

2.8% (95% CI: 1.89-3.68%) per 2.2 mg/m³ (cardiovascular disease - elderly)

Schwartz, 1999

Chicago, Illinois, 1986-89

1-hour maximum

9% (95% CI: 6-12%) (congestive heart failure)

Morris and Naumova, 1998

10 Canadian cities, 1981-91

1-hour maximum
8-hour maximum

2.9
2.0

6.5% (95% CI: 3.10%) per 2 mg/m³ one-hour CO (congestive heart failure - elderly)

Burnett et al, 1997

Seven US cities, 1986-89

1-hour maximum

2.2-5.0

10% (95% CI: 3-18%) to 36% (95% CI: 28-46%) per 10 mg/m³ (congestive heart failure)

Morris et al, 1995

London, UK

24-hour average

1.1

2.1% (95% CI: 0.7-3.5%) (acute myocardial infarction)

Polniecki et al, 1997