Table 2. Cooking- and heating-related characteristics of study participants by study area.
| Characteristics | Suzhou (Urban) | Gansu (Rural) | Henan (Rural) | Overall |
|---|---|---|---|---|
| Cooking exposure, n (%) | ||||
| Personal regular | 108 (72.5) | 117 (78.0) | 117 (78.0) | 342 (76.2) |
| Household regular, personal non-regular | 23 (15.4) | 21 (14.0) | 9 (6.0) | 53 (11.8) |
| Non-regular | 18 (12.1) | 12 (8.0) | 24 (16.0) | 54 (12.0) |
| Cooking duration - hours, mean (SD)* | 2.7 (0.7) | 2.8 (0.8) | 2.5 (0.7) | 2.7 (0.7) |
| Number of cooking fuel reported, median (IQR)* | 1 (1-2) | 3 (2-3) | 2 (2-3) | 2 (2-3) |
| Cooking fuel combination for most meals, n (%)* | ||||
| All reported fuel(s) was used sometimes | 66 (50.4) | 8 (5.8) | 15 (11.9) | 89 (22.5) |
| Clean fuels only | 64 (48.9) | 48 (34.8) | 43 (34.1) | 155 (39.2) |
| Clean fuels and coal | 0 (0) | 11 (8.0) | 35 (27.8) | 46 (11.7) |
| Clean fuels and mixed solid fuels | 0 (0) | 5 (3.6) | 0 (0) | 5 (1.3) |
| Clean fuels and wood | 0 (0) | 64 (46.4) | 0 (0) | 64 (16.2) |
| Coal only | 0 (0) | 1 (0.7) | 33 (26.2) | 34 (8.6) |
| Mixed solid fuels | 0 (0) | 1 (0.7) | 0 (0) | 1 (0.3) |
| Wood only | 1 (0.8) | 0 (0) | 0 (0) | 1 (0.3) |
| Cooking fuel in those reported all fuels were used sometimes, n (%)*,† | ||||
| Clean fuels | 66 (100) | 6 (75.0) | 7 (46.7) | 79 (88.8) |
| Clean fuels and coal | 0 (0) | 0 (0) | 8 (53.3) | 8 (9.0) |
| Clean fuels and wood | 0 (0) | 2 (25.0) | 0 (0) | 2 (2.3) |
| Ventilated kitchen, n(%)* | 126 (98.4) | 96 (70.1) | 58 (45.0) | 280 (71.1) |
| Windows opened when cooking, n(%)* | ||||
| Always | 78 (60.9) | 128 (93.4) | 89 (69.0) | 295 (74.9) |
| Sometimes | 17 (13.3) | 8 (5.8) | 22 (17.1) | 47 (11.9) |
| Rarely/never/no window in the kitchen | 33 (25.8) | 1 (0.7) | 18 (14.0) | 52 (13.2) |
| Smoky kitchen when cooking, n(%)* | ||||
| Always | 1 (0.8) | 38 (27.7) | 7 (5.4) | 46 (11.7) |
| Sometimes | 6 (4.7) | 68 (49.6) | 31 (24.0) | 105 (26.7) |
| Rarely/never | 121 (94.5) | 31 (22.6) | 91 (70.5) | 243 (61.7) |
| Heating frequency, n (%) | ||||
| Daily or almost every day | 25 (16.8) | 136 (90.7) | 111 (74.0) | 272 (60.6) |
| A few times a week | 10 (6.7) | 0 (0.0) | 3 (2.0) | 13 (2.9) |
| A few times a month | 8 (5.4) | 0 (0.0) | 3 (2.0) | 11 (2.5) |
| No heating | 106 (71.1) | 14 (9.3) | 33 (22.0) | 153 (34.1) |
| Reason of no heating, n (%) | ||||
| No such need | 106 (100.0) | 12 (85.7) | 29 (87.9) | 147 (96.1) |
| Cannot afford | 0 (0.0) | 1 (7.1) | 0 (0.0) | 1 (0.7) |
| Inconvenience | 0 (0.0) | 1 (7.1) | 4 (12.1) | 5 (3.3) |
| Typical heating duration, median (IQR) ‡ | 3 (2-3) | 24 (24-24) | 24 (24-24) | |
| Presence of central heating system, n (%) ‡ | 1 (2.3) | 6 (4.4) | 5 (4.3) | 12 (4.1) |
| Number of heating fuel reported, median (IQR) ‡ | 1 (1-1) | 1 (1-2) | 1 (1-1) | 1 (1-1) |
| Heating fuel combination (used for longest hour), n (%) ‡ | ||||
| Clean fuels only | 43 (100) | 3 (2.2) | 6 (5.1) | 52 (17.6) |
| Coal only | 0 (0) | 62 (45.6) | 100 (85.5) | 162 (54.7) |
| Charcoal only | 0 (0) | 0 (0) | 9 (7.7) | 9 (3.0) |
| Wood only | 0 (0) | 48 (35.3) | 0 (0) | 48 (16.2) |
| Mixed solid fuels | 0 (0) | 23 (16.9) | 0 (0) | 23 (7.8) |
| Others | 0 (0) | 0 (0) | 2 (1.7) | 2 (0.7) |
| Ventilated heat-stove ‡ | 9 (20.9) | 133 (97.8) | 107 (91.5) | 237 (84.1) |
| Smoky home while heating ‡ | ||||
| Always | 0 (0.0) | 1 (0.7) | 0 (0.0) | 1 (0.3) |
| Sometimes | 0 (0.0) | 111 (81.6) | 2 (1.7) | 113 (38.2) |
| Rarely/never | 43 (100.0) | 24 (17.7) | 115 (98.3) | 182 (61.5) |
*
Percentage counted only among participants who live in households where regular cooking occurred.
†
Reported as fuel used for cooking sometimes.
‡
Percentage counted only among those reported using heating for at least a few times a month.