Table 1.
Age- and sex-adjusted 24-hour geometric mean (95 % CI) PM2.5 concentrations (μg/m3) recorded in the personal, kitchen, and living room monitors by season and key characteristics.
| Characteristics | Summer (N⁎ = 384) |
Winter (N⁎ = 364) |
||||||
|---|---|---|---|---|---|---|---|---|
| N⁎ | Personal | Kitchen | Living room | N⁎ | Personal | Kitchen | Living room | |
| Personal characteristics | ||||||||
| Age† | ||||||||
| < 65 years | 323 | 42.0 (40.2–43.9) | 43.9 (41.8–46.2) | 33.5 (32.1–34.9) | 305 | 59.5 (56.2–63.1) | 82.8 (77.2–88.8) | 56.1 (52.9–59.4) |
| ≥ 65 years | 61 | 33.5 (30.7–36.5) | 43.0 (39.0–47.5) | 31.9 (29.4–34.6) | 59 | 48.9 (43.6–54.9) | 62.9 (54.7–72.2) | 49.2 (43.9–55.1) |
| Sex‡ | ||||||||
| Female | 287 | 40.9 (39.3–42.6) | 44.4 (42.4–46.5) | 32.7 (31.4–33.9) | 267 | 66.1 (62.6–69.8) | 87.6 (82.1–93.5) | 61.1 (57.9–64.5) |
| Male | 97 | 39.8 (37.2–42.7) | 43.3 (40.1–46.9) | 33.7 (31.6–36.0) | 97 | 50.2 (45.8–55.0) | 72.0 (64.5–80.4) | 49.4 (45.1–54.1) |
| Region | ||||||||
| Rural | 249 | 36.3 (34.7–38.0) | 53.4 (50.7–56.3) | 48.9 (46.7–51.1) | 251 | 66.5 (62.7–70.7) | 107.7 (100.3–115.6) | 74.5 (70.2–79.0) |
| Urban | 135 | 28.2 (26.6–29.8) | 30.7 (28.7–32.8) | 28.6 (26.9–30.3) | 113 | 36.8 (33.9–40.0) | 42.1 (38.1–46.5) | 33.7 (31.0–36.6) |
| Education | ||||||||
| No formal education | 97 | 48.9 (45.1–53.1) | 52.3 (47.6–57.5) | 38.2 (35.3–41.3) | 92 | 75.8 (67.9–84.7) | 112.6 (98.7–128.5) | 70.2 (62.9–78.3) |
| Primary & middle school | 133 | 38.8 (36.5–41.4) | 42.8 (39.8–46.0) | 30.4 (28.7–32.3) | 125 | 58.5 (53.8–63.5) | 84.0 (76.1–92.8) | 58.4 (53.8–63.4) |
| High school or above | 154 | 38.4 (36.3–40.7) | 41.6 (39.0–44.4) | 33.3 (31.5–35.1) | 147 | 50.9 (47.1–55.0) | 66.0 (60.2–72.4) | 47.4 (44.0–51.2) |
| Occupation | ||||||||
| Agricultural worker | 140 | 53.2 (50.3–56.3) | 59.9 (56.2–63.9) | 38.0 (36.0–40.2) | 138 | 74.6 (69.2–80.4) | 120.0 (109.6–131.3) | 69.0 (63.9–74.4) |
| Factory worker | 20 | 34.4 (29.7–39.9) | 39.1 (33.0–46.2) | 31.7 (27.4–36.6) | 18 | 59.0 (47.9–72.7) | 59.2 (46.0–76.1) | 36.9 (29.9–45.5) |
| Home-maker | 106 | 40.1 (37.3–43.2) | 43.2 (39.7–47.0) | 32.9 (30.6–35.4) | 109 | 68.6 (62.3–75.5) | 88.4 (78.8–99.2) | 65.3 (59.3–72.0) |
| Non-manual labour | 9 | 33.4 (27.0–41.4) | 29.0 (22.7–37.0) | 26.2 (21.2–32.4) | 10 | 62.0 (47.1–81.8) | 46.0 (33.0–64.2) | 45.2 (34.2–59.7) |
| Self/un-employed or other | 109 | 29.1 (27.2–31.1) | 30.7 (28.4–33.1) | 28.5 (26.7–30.5) | 89 | 31.6 (28.7–34.8) | 43.7 (39.0–49.1) | 37.4 (33.9–41.2) |
| Current active smoker | ||||||||
| No | 328 | 38.6 (36.5–40.8) | 44.7 (42.0–47.6) | 29.2 (27.7–30.8) | 303 | 52.1 (48.2–56.3) | 75.0 (68.3–82.3) | 49.1 (45.5–53.0) |
| Yes | 56 | 45.1 (40.7–50.1) | 41.9 (37.2–47.2) | 45.6 (41.3–50.3) | 61 | 71.9 (62.7–82.4) | 90.2 (76.5–106.3) | 70.5 (61.6–80.7) |
| Passive smoking exposure§ | ||||||||
| No | 200 | 38.7 (36.7–40.9) | 42.9 (40.4–45.6) | 30.6 (29.1–32.2) | 180 | 50.7 (47.1–54.6) | 51.8 (48.1–55.7) | 75.9 (69.5–83.0) |
| Yes | 184 | 42.0 (39.9–44.3) | 44.8 (42.2–47.6) | 35.8 (34.1–37.7 | 184 | 64.0 (59.8–68.5) | 57.7 (53.9–61.7) | 82.4 (75.9–89.5) |
| Household size⁎⁎ | ||||||||
| ≤ 4 persons | 196 | 39.6 (37.7–41.7) | 42.6 (40.2–45.2) | 34.2 (32.6–35.9) | 190 | 55.5 (51.8–59.5) | 78.9 (72.6–85.8) | 55.9 (52.2–59.9) |
| > 4 persons | 188 | 41.2 (39.0–43.5) | 45.3 (42.6–48.1) | 32.0 (30.5–33.7) | 174 | 60.0 (55.8–64.5) | 79.9 (73.3–87.2) | 53.8 (50.1–57.8) |
| Cooking frequency | ||||||||
| Daily personal cooking | 301 | 41.4 (39.2–43.8) | 43.6 (41.0–46.5) | 34.4 (32.6–36.3) | 280 | 59.2 (54.7–64.1) | 82.4 (74.9–90.6) | 55.3 (51.1–59.8) |
| Daily household cooking | 41 | 37.6 (33.7–42.1) | 49.2 (43.4–55.9) | 31.3 (28.2–34.8) | 44 | 52.1 (44.9–60.4) | 75.2 (63.0–89.8) | 54.6 (47.2–63.2) |
| Infrequent cooking | 42 | 39.6 (35.6–44.1) | 39.9 (35.3–45.1) | 30.8 (27.8–34.1) | 40 | 58.3 (50.4–67.5) | 74.5 (62.5–88.7) | 54.1 (46.9–62.5) |
| Smoky home while cooking†† | ||||||||
| No | 222 | 37.2 (35.2–39.2) | 40.9 (38.5–43.5) | 32.4 (30.8–34.1) | 196 | 45.7 (42.4–49.1) | 61.8 (56.6–67.6) | 46.8 (43.4–50.3) |
| Yes | 120 | 46.1 (43.0–49.3) | 53.7 (49.7–58.0) | 35.1 (32.9–37.4) | 127 | 74.9 (68.7–81.6) | 119.5 (107.7–132.5) | 67.7 (62.1–73.8) |
| Smoky home while heating‡‡ | ||||||||
| No | 163 | 44.3 (41.8–47.0) | 44.1 (41.3–47.2) | 34.0 (32.1–35.9) | 151 | 55.3 (51.2–59.8) | 72.6 (66.2–79.6) | 54.2 (50.2–58.4) |
| Yes | 85 | 39.9 (36.8–43.1) | 51.4 (46.9–56.4) | 29.5 (27.4–31.8) | 101 | 82.0 (74.9–89.7) | 127.9 (114.8–142.4) | 72.5 (66.4–79.2) |
⁎
Number of subjects.
†
Only adjusted for sex. The age cut-off was set to separate middle-aged adults and elderly following the convention.
‡
Only adjusted for age.
§
Total passive smoking exposure (frequency per week) of >3–5 days/week was defined as exposed (“Yes”).
⁎⁎
The 4-person household size cut off was set on the median of the reported household size in the sample.
††
Restricted to individuals who reported frequent household or personal cooking only.
‡‡
Restricted to individuals who reported heating in winter only.