Table 3.
Indoor air pollution and risks of lung cancer among female non-smokers
| Case |
Control |
Cryde OR (95%CI) |
Adjusted OR (95%CI)a |
|||
|---|---|---|---|---|---|---|
| N | % | N | % | |||
| Housing | ||||||
| Type of housing | ||||||
| Single-story house | 124 | 76.5 | 108 | 49.5 | 1 | 1 |
| Multi-story house | 38 | 23.5 | 110 | 50.5 | 0.30 (0.19,0.47) | 0.33(0.20, 0.54) |
| Total | 162 | 218 | ||||
| Number of windows/ m2 | ||||||
| High (>0.077) | 43 | 27.0 | 75 | 35.9 | 1 | 1 |
| Medium (0.05 ~ 0.077) | 39 | 24.5 | 72 | 34.5 | 0.95 (0.55,1.62) | 0.95 (0.54,1.66) |
| Low ( 0.05) | 77 | 48.4 | 62 | 29.7 | 2.17 (1.31,3.58) | 2.18 (1.30,3.66) |
| Total | 159 | 209 | ||||
| P trend | 0.0018 | 0.0026 | ||||
| Open windows frequently | ||||||
| Yes | 127 | 81.4 | 198 | 92.5 | 1 | 1 |
| No | 29 | 18.6 | 16 | 7.5 | 2.83 (1.48,5.41) | 2.50 (1.28,4.88) |
| Total | 156 | 214 | ||||
| Cooking | ||||||
| Cooking place | ||||||
| Outdoor kitchen/ never cooked | 38 | 28.2 | 60 | 29.1 | 1 | 1 |
| Indoor Kitchen | 41 | 30.4 | 109 | 52.9 | 0.59 (0.35,1.02) | 0.64 (0.37,1.13) |
| Living room | 39 | 28.9 | 27 | 13.1 | 2.28 (1.21,4.31) | 2.62 (1.35,5.08) |
| Bed room | 17 | 12.6 | 10 | 4.9 | 2.68 (1.11,6.47) | 2.29 (0.93,5.63) |
| Total | 135 | 206 | ||||
| Ventilator in kitchen | ||||||
| Yes | 37 | 24.2 | 83 | 38.4 | 1 | 1 |
| No | 116 | 75.8 | 133 | 61.6 | 1.96 (1.23,3.10) | 1.78 (1.09,2.90) |
| Total | 153 | 216 | ||||
| Current frequency of cooking | ||||||
| Never, <7/week | 13 | 9.0 | 32 | 15.2 | 1 | 1 |
| 7/week | 35 | 24.1 | 43 | 20.5 | 2.00 (0.92,4.39) | 1.44 (0.64,3.27) |
| 8–14/week | 67 | 46.2 | 118 | 56.2 | 1.40 (0.69,2.85) | 1.11 (0.53,2.34) |
| 15–21/week | 30 | 20.7 | 17 | 8.1 | 4.34 (1.81,10.44) | 3.30 (1.32,8.22) |
| Total | 145 | 210 | ||||
| P trend | 0.0219 | 0.0733 | ||||
| Cooking fuels | ||||||
| onlyb | ||||||
| Clean fuels ≥ 15 yrs | 28 | 17.5 | 64 | 30.3 | 1 | 1 |
| Clean fuels <15 yrs | 41 | 25.6 | 92 | 43.6 | 1.02(0.57, 1.81) | 1.14 (0.63,2.06) |
| Solid fuel only | 91 | 56.9 | 55 | 26.1 | 3.78(2.17, 6.59) | 4.08 (2.17,7.67) |
| Total | 160 | 211 | ||||
| Heating | ||||||
| Clean/no heatingc | 56 | 34.8 | 124 | 59.1 | 1 | 1 |
| Coal furnace | 70 | 43.5 | 71 | 33.8 | 2.18 (1.38,3.45) | 2.00 (1.24,3.23) |
| Coke oven | 20 | 12.4 | 12 | 5.7 | 3.69 (1.69,8.07) | 3.20 (1.40,7.32) |
| Heatable brick bed | 15 | 9.3 | 3 | 1.4 | 11.07 (3.08,39.78) | 8.13 (2.20, 30.08) |
| Total | 161 | 210 | ||||
| Indoor Air Pollution Indexd | ||||||
| 0 | 12 | 8.0 | 28 | 13.2 | 1 | 1 |
| 1–2 | 43 | 28.5 | 113 | 53.0 | 0.89(0.41, 1.90) | 0.97(0.44, 2.11) |
| 3–5 | 96 | 63.5 | 72 | 33.8 | 3.11(1.48, 6.53) | 3.09(1.39, 6.86) |
| Total | 151 | 213 | ||||
| P trend | <.0001 | <.0001 | ||||
a
Odds Ratios were adjusted for age, education level, annual personal income and pack-year.
b
Using natural gas, liquid gas or electric stove,
c
Cleaning heating: Air conditioning / heater/ electrics/
d
IAP index calculated by characterizing exposure to passive smoking, solid fuel for heating, solid fuels for cooking, no ventilator in kitchen and low frequency of opening windows as (5) significant risk factors for lung cancer. An IAP index of 5 signified exposure to all 5 risk factors, with 0 being exposure to none of the risk factors listed.