Table 1. Characteristics of the Study Population in Xuanwei and Fuyuan.
| phase
I |
phase
II |
all | |||
|---|---|---|---|---|---|
| Xuanwei | Fuyuan | Xuanwei | Fuyuan | ||
| subjects, n | 74 | 74 | 31 | 37 | 163a |
| villages, n | 15 | 15 | 8 | 8 | 30 |
| age (in 2009), mean ± SD | 54.0 ± 14.9 | 56.7 ± 13.7 | 62.0 ± 11.3 | 58.9 ± 12.2 | 56.0 ± 14.4 |
| stove type, n(%) | |||||
| vented stove | 34(45.9) | 19(25.7) | 12(38.7) | 10(27.0) | 75(34.7) |
| high stove with chimney | 13(17.6) | 5(6.8) | 6(19.4) | 1(2.7) | 25(11.6) |
| low stove with chimney | 8(10.8) | 11(14.9) | 2(6.5) | 6(16.2) | 27(12.5) |
| multiple stoves with chimneys | 13(17.6) | 3(4.1) | 4(12.9) | 3(8.1) | 23(10.6) |
| unvented stove | 4(5.4) | 12(16.2) | 0(0.0) | 11(29.7) | 27(12.5) |
| high stove without chimney | 0(0.0) | 6(8.1) | 0(0.0) | 2(5.4) | 8(3.7) |
| low stove without chimney | 0(0.0) | 0(0.0) | 0(0.0) | 1(2.7) | 1(0.5) |
| multiple stoves without any chimney | 4(5.4) | 6(8.1) | 0(0.0) | 8(21.6) | 18(8.3) |
| portable stove | 2(2.7) | 19(25.7) | 1(3.2) | 8(21.6) | 30(13.9) |
| firepit | 3(4.1) | 7(9.5) | 3(9.7) | 3(8.1) | 16(7.4) |
| mixed ventilation stovesb | 30(40.5) | 13(17.6) | 13(41.9) | 5(13.5) | 61(28.2) |
| unknown ventilation stove | 1(1.4) | 4(5.4) | 2(6.5) | 0(0.0) | 7(3.2) |
| solid fuel type, n(%) | |||||
| smoky coal | 42(56.8) | 32(43.2) | 19(61.3) | 6(16.2) | 99(45.8) |
| smokeless coal | 0(0.0) | 13(17.6) | 1(3.2) | 5(13.5) | 19(8.8) |
| “mixed” coalc | 9(12.2) | 5(6.8) | 1(3.2) | 4(10.8) | 19(8.8) |
| wood | 3(4.1) | 1(1.4) | 2(6.5) | 6(16.2) | 11(5.1) |
| plant materialsd | 4(5.4) | 3(4.1) | 1(3.2) | 0(0.0) | 9(4.2) |
| “mixed” fuele | 16(21.6) | 18(24.3) | 6(19.4) | 16(43.2) | 56(25.9) |
| unknown | 0(0.0) | 2(2.7) | 1(3.2) | 0(0.0) | 3(1.4) |
| median length of stove operation, hours per day | 4 | 3.3 | 8 | 13 | 5.1 |
a
There were 216 visits to the households in total: of the 148 subjects visited in phase I, 53 were revisited the second time, and 15 new subjects were enrolled in phase II.
b
Refers to the use of vented stove and unvented stove/portable stove simultaneously.
c
Refers to the use of combinations of smoky and smokeless coal and also to the use of prepared coal briquettes.
d
Plant materials include combinations of wood, tobacco stem and corncob.
e
Refers to combinations of wood, plant materials and coal.