NO2 levels in and characteristics of the homes of children in the BAMSE case-control study
| Dwelling location | Building age | Number of dwellings (cases)* | Number of single family houses | Number with natural draft† | Mean ACH‡ | Number with gas stoves | Mean NO2 indoor§, µg/m3 [range] | Mean NO2 outdoor§, µg/m3 [range] |
|---|---|---|---|---|---|---|---|---|
| *Number of cases given in parenthesis throughout table. | ||||||||
| †Natural draft ventilation—that is, ventilation without support by fans. | ||||||||
| ‡Air change rate per hour. | ||||||||
| §Mean NO2 levels are presented for the entire areas; range of concentrations in individual measurements given in brackets. | ||||||||
| Urban | 1939 or earlier | 111 (30) | 0 | 83 (22) | 0.60 | 42 (12) | 18.3 | 31.5 |
| 1940–75 | 7 (4) | 0 | 1 (1) | 0.68 | 0 | [8.0–45.1] | [17.9–46.7] | |
| 1976 or later | 11 (4) | 0 | 1 (0) | 0.75 | 0 | |||
| Semi-urban | 1939 or earlier | 14 (2) | 2 (0) | 7 (2) | 0.57 | 2 (1) | 12.2 | 21.6 |
| 1940–75 | 172 (60) | 1 (0) | 29 (8) | 0.68 | 1 (0) | [4.4–25.1] | [8.7–36.4] | |
| 1976 or later | 88 (33) | 4 (2) | 0 | 0.77 | 0 | |||
| Suburban | 1939 or earlier | 12 (3) | 11 (2) | 12 (3) | 0.71 | 1 | 8.1 | 13.7 |
| 1940–75 | 57 (19) | 57 (19) | 47 (16) | 0.43 | 0 | [2.3–21.1] | [6.0–29.0] | |
| 1976 or later | 68 (26) | 59 (21) | 3 (1) | 0.55 | 0 | |||