Table 1. Average air pollution levels and participant characteristics in the 6 study areas.
| Miyagi prefecture | Aichi prefecture | Osaka prefecture | ||||||
| Wakuya/Tajiri towns (entire towns) |
Sendai city (6 areas in Aoba and Miyagino wards) |
Inuyama city (2 areas in the city) |
Nagoya city (5 areas in Chikusa ward) |
Nose/Kanan/ Kumatori towns (entire towns) |
Osaka city (Higashinari ward) |
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| Year of baseline survey | 1984 | 1984 | 1985 | 1985 | 1983–1985a | 1984 | ||
| Number of participants in collected datasets | 14 571 | 16 774 | 12 001 | 21 514 | 18 608 | 17 147 | ||
| Number of participants in analytic cohorts | 7813 | 9924 | 7917 | 13 653 | 10 490 | 13 723 | ||
| Age at baseline; mean (SD) | 56.8 (11.3) | 57.5 (11.2) | 56.2 (11.3) | 57.7 (11.1) | 55.9 (11.5) | 57.6 (11.3) | ||
| 40–49 years | 30.4% | 28.0% | 34.0% | 27.0% | 35.5% | 28.4% | ||
| 50–59 years | 33.1% | 32.4% | 31.1% | 33.0% | 30.9% | 31.6% | ||
| 60–69 years | 20.3% | 23.4% | 20.3% | 23.1% | 18.6% | 22.9% | ||
| ≥70 years | 16.2% | 16.1% | 14.6% | 16.9% | 15.1% | 17.2% | ||
| Person-years of follow-up | 71 579 | 80 927 | 70 819 | 114 497 | 94 917 | 117 599 | ||
| % move-out during follow-up | 2.9% | 22.4% | 8.0% | 20.3% | 5.5% | 11.9% | ||
| Number of deaths | ||||||||
| Lung cancer | 49 | 60 | 58 | 132 | 74 | 145 | ||
| Respiratory diseasesb | 78 | 116 | 69 | 126 | 120 | 181 | ||
| All causes | 973 | 935 | 789 | 1333 | 1033 | 1624 | ||
| 10-year average air pollution levels | ||||||||
| SPM (µg/m3) | 1974–1983 | 24.0 | 44.8 | 46.3 | 49.7 | 36.0 | 59.9 | |
| 1984–1993 | 21.9 | 29.0 | 37.4 | 43.7 | 36.2 | 45.0 | ||
| PM2.5 (µg/m3)c | 1974–1983 | 16.8 | 31.4 | 32.4 | 34.8 | 25.2 | 41.9 | |
| 1984–1993 | 15.3 | 20.3 | 26.2 | 30.6 | 25.3 | 31.5 | ||
| SO2 (ppb) | 1974–1983 | 2.4 | 12.0 | 9.5 | 10.4 | 13.5 | 19.0 | |
| 1984–1993 | 2.3 | 5.5 | 6.8 | 7.7 | 6.3 | 10.6 | ||
| NO2 (ppb) | 1974–1983 | 1.2 | 18.3 | 13.6 | 20.3 | 14.6 | 33.7 | |
| 1984–1993 | 2.6 | 16.1 | 16.0 | 23.9 | 16.0 | 33.0 | ||
| Results of baseline survey (1983–1985) | ||||||||
| Smoking status (%) | ||||||||
| Current smokerse | 30.3% | 29.1% | 35.6% | 30.1% | 35.1% | 33.9% | ||
| Former smokerse | 9.0% | 14.4% | 15.4% | 17.4% | 9.9% | 13.9% | ||
| Amount of smoking (pack-years) | ||||||||
| Current smokers; mean (SD)f | 31.5 (17.4) | 32.0 (19.6) | 33.8 (19.4) | 34.7 (22.3) | 34.8 (19.6) | 34.5 (20.8) | ||
| Former smokers; mean (SD)f | 27.9 (20.5) | 29.4 (24.5) | 29.4 (28.0) | 30.3 (28.2) | 28.5 (23.4) | 29.8 (26.5) | ||
| Passive smoking (%) | ||||||||
| Currently from family memberse | 62.4% | 46.2% | 48.4% | 39.7% | 54.3% | 50.4% | ||
| During childhood from parentse | 71.4% | 75.1% | 74.3% | 75.3% | 79.3% | 82.6% | ||
| Daily green and yellow vegetable consumption (%)e | 52.1% | 58.0% | 41.8% | 48.3% | 36.6% | 34.4% | ||
| Daily consumption of other vegetables (%)e | 75.5% | 67.7% | 63.3% | 62.1% | 49.3% | 41.9% | ||
| Daily fruit consumption (%)e | 64.9% | 65.0% | 34.8% | 54.4% | 49.8% | 47.2% | ||
| Use of indoor charcoal or briquette braziers for heating (%)e |
44.8% | 7.1% | 3.0% | 1.5% | 10.1% | 6.3% | ||
| Occupation with potential risk (%)d,e | 29.7% | 24.7% | 40.5% | 27.1% | 32.0% | 36.3% | ||
| History of respiratory diseases (%)e | 6.1% | 6.9% | 8.6% | 10.4% | 7.6% | 6.6% | ||
| Health insurance type (%) | ||||||||
| National health insurancee | 67.8% | 44.2% | 42.1% | 42.2% | 47.1% | 56.2% | ||
| Government/union-managed health insurancee | 21.1% | 38.8% | 48.8% | 47.9% | 41.9% | 40.1% | ||
| Mutual aid associations health insurancee | 9.0% | 14.7% | 8.2% | 9.0% | 10.0% | 2.2% | ||
| Others | 2.1% | 2.3% | 0.9% | 0.9% | 0.9% | 1.5% | ||
NO2, nitrogen dioxide; PM2.5, particulate matter <2.5 µm in aerodynamic diameter; SO2, sulfur dioxide; SPM, suspended particulate matter.
a1983 in Nose, 1984 in Kanan, and 1985 in Kumatori towns.
bFor respiratory diseases, numbers of deaths were counted after excluding 4970 participants with a previous diagnosis of pneumonia, asthma, chronic bronchitis, emphysema, or pneumoconiosis.
cEstimated by multiplying the level of SPM by 0.7.
dExperience of occupation with potential risk of exposure to gases, fumes, or dust.
eSignificant difference among areas (chi-square test; P < 0.0001).
fSignificant difference among areas (ANOVA; P < 0.0001).