Table 3

Impact of differential smoking prevalence on lung cancer and coronary-heart-disease mortality across deciles of fine particulate matter (PM2.5) exposure, Canadian Community Health Survey (CCHS) participants aged 35 years and older

Cigarette smoking prevalence (%)Lung cancerCoronary heart disease
Exposure categoryRange of PM2.5 valuesMean PM2.5 (μg/m3)Never smokersFormer smokersCurrent smokersEstimated mortality*Percentage change due to smokingEstimated mortality*Percentage change due to smoking
1<4.443.7525.350.624.1124.50282.90
24.44 to <4.964.7225.550.424.1124.3−0.1282.8−0.1
34.96 to <5.385.1726.650.123.3121.9−2.1280.1−1.0
45.38 to <5.995.6727.649.323.1120.7−3.1278.8−1.5
55.99 to <6.816.3928.051.121.0116.7−6.3274.4−3.0
66.81 to <7.487.1130.548.620.9114.2−8.3271.6−4.0
77.48 to <8.698.0127.948.923.2120.6−3.2278.7−1.5
88.69 to <11.429.9627.749.123.2120.8−3.0278.9−1.4
911.42 to <13.8012.6131.646.022.5116.1−6.8274.2−3.1
1013.80+15.8435.143.221.7111.4−10.5269.1−4.9
  • * 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.