Table 2. Adjusted HRs for lung cancer associated with a 10-unit increase in the average concentration of air pollutantsa .
| Model description | Category | Number of deaths |
Person-years | SPM (µg/m3) | PM2.5 (µg/m3)b | SO2 (ppb) | NO2 (ppb) | ||||
| HR | 95% CI | HR | 95% CI | HR | 95% CI | HR | 95% CI | ||||
| Sex- and age-adjusted | (All) | 518 | 550 339 | 1.18 | (1.13–1.24) | 1.27 | (1.19–1.36) | 1.36 | (1.20–1.54) | 1.20 | (1.17–1.24) |
| Base modelc | (All) | 518 | 550 339 | 1.16 | (1.08–1.25) | 1.24 | (1.12–1.37) | 1.26 | (1.07–1.48) | 1.17 | (1.10–1.26) |
| Full modeld | (All) | 421 | 472 762 | 1.16 | (1.06–1.25) | 1.23 | (1.09–1.38) | 1.19 | (0.97–1.45) | 1.15 | (1.06–1.24) |
| By sexe | Male | 407 | 257 120 | 1.17 | (1.09–1.26) | 1.26 | (1.14–1.39) | 1.30 | (1.12–1.52) | 1.18 | (1.11–1.26) |
| Female | 111 | 293 219 | 1.12 | (0.99–1.26) | 1.17 | (0.98–1.39) | 1.11 | (0.88–1.40) | 1.13 | (1.01–1.27) | |
| By sex and smoking statusf | Male current smokers | 292 | 146 031 | 1.23 | (1.14–1.34) | 1.35 | (1.20–1.52) | 1.36 | (1.06–1.75) | 1.23 | (1.12–1.35) |
| Male former smokers | 90 | 63 092 | 1.08 | (0.83–1.39) | 1.11 | (0.77–1.60) | 1.25 | (0.75–2.10) | 1.13 | (0.88–1.44) | |
| Female never smokers | 73 | 254 145 | 1.11 | (1.01–1.22) | 1.16 | (1.02–1.33) | 1.09 | (0.92–1.29) | 1.11 | (1.02–1.20) | |
| Base model, excluding participants with a history of respiratory diseasesc,g |
(No history of respiratory disease) | 438 | 509 369 | 1.15 | (1.06–1.26) | 1.23 | (1.08–1.39) | 1.22 | (1.02–1.45) | 1.16 | (1.07–1.25) |
| Base model, using average concentrations during the follow-up periodc,h |
(All) | 518 | 550 339 | 1.27 | (1.14–1.41) | 1.41 | (1.21–1.64) | 1.97 | (1.41–2.75) | 1.21 | (1.10–1.33) |
CI, confidence interval; HR, hazard ratio; NO2, nitrogen dioxide; PM2.5, particulate matter <2.5 µm in aerodynamic diameter; SO2, sulfur dioxide; SPM: suspended particulate matter.
a10-year average concentrations (1974–1983) before baseline survey were used, unless otherwise specified.
bEstimated by multiplying the level of SPM by 0.7.
cAdjusted for sex, age (continuous), smoking status (current, former, or never), pack-years (0 to <10, 10 to <20, ≥20), smoking status of family members (current smoking/no current smoking), daily green and yellow vegetable consumption (yes/no), daily fruit consumption (yes/no), and indoor charcoal or briquette braziers used for heating (yes/no).
dBase model, with additional adjustment for smoking status of parents in childhood (current smoking/no current smoking), daily consumption of vegetables other than green and yellow vegetables (yes/no), occupation (experience in occupation with potential exposure to gases, fumes, or dust or not), health insurance (4 categories). 9289 participants were excluded because of missing data for smoking status of parents, non-green/yellow vegetable consumption, occupation, and/or health insurance.
eBase model, excluding adjustment for sex. Pack-years were adjusted with different categories for males and females (0 to <10, 10 to <20, 20 to <30, 30 to <40, ≥40 for males, 0 to <10, 10 to <20, ≥20 for females).
fBase model, excluding adjustment for sex and smoking status. Pack-years were adjusted using 5 categories for male current or former smokers (0 to <10, 10 to <20, 20 to <30, 30 to <40, ≥40).
g4970 participants with a previous diagnosis of pneumonia, asthma, chronic bronchitis, emphysema, or pneumoconiosis were excluded.
hBase model, using the 10-year average concentrations (1984–1993) during the follow-up period.