Cigarette smoking prevalence (%) | Lung cancer | Coronary heart disease | |||||||
Exposure category | Range of PM2.5 values | Mean PM2.5 (μg/m3) | Never smokers | Former smokers | Current smokers | Estimated mortality* | Percentage change due to smoking† | Estimated mortality* | Percentage change due to smoking† |
1 | <4.44 | 3.75 | 25.3 | 50.6 | 24.1 | 124.5 | 0 | 282.9 | 0 |
2 | 4.44 to <4.96 | 4.72 | 25.5 | 50.4 | 24.1 | 124.3 | −0.1 | 282.8 | −0.1 |
3 | 4.96 to <5.38 | 5.17 | 26.6 | 50.1 | 23.3 | 121.9 | −2.1 | 280.1 | −1.0 |
4 | 5.38 to <5.99 | 5.67 | 27.6 | 49.3 | 23.1 | 120.7 | −3.1 | 278.8 | −1.5 |
5 | 5.99 to <6.81 | 6.39 | 28.0 | 51.1 | 21.0 | 116.7 | −6.3 | 274.4 | −3.0 |
6 | 6.81 to <7.48 | 7.11 | 30.5 | 48.6 | 20.9 | 114.2 | −8.3 | 271.6 | −4.0 |
7 | 7.48 to <8.69 | 8.01 | 27.9 | 48.9 | 23.2 | 120.6 | −3.2 | 278.7 | −1.5 |
8 | 8.69 to <11.42 | 9.96 | 27.7 | 49.1 | 23.2 | 120.8 | −3.0 | 278.9 | −1.4 |
9 | 11.42 to <13.80 | 12.61 | 31.6 | 46.0 | 22.5 | 116.1 | −6.8 | 274.2 | −3.1 |
10 | 13.80+ | 15.84 | 35.1 | 43.2 | 21.7 | 111.4 | −10.5 | 269.1 | −4.9 |
↵* Per 100 000; based on Canadian age–sex-specific lung-cancer mortality36 weighted to the age–sex distribution of CCHS participants, the prevalence of never, former and current smokers, as well as the RR of lung cancer (based on American Cancer Society Cancer Prevention Study-II data); assumes exposure to ambient PM2.5 is unrelated to lung cancer mortality (see equations (1)–(3)).
↵† Relative to mortality rates in the lowest PM2.5 exposure category.