TABLE 2.
Distribution of blood trihalomethane (THM) concentrations according to tobacco smoke exposure (National Health and Nutrition Examination Survey 2005–2012)
| TCM (pg·mL−1) | BDCM (pg·mL−1) | DBCM (pg·mL−1) | TBM (pg·mL−1) | Br-THMs (pg·mL−1) | TTHMs (pg·mL−1) | |
| All (n=2359) | ||||||
| n | 2266 | 2342 | 2309 | 2305 | 2253 | 2161 |
| % >LOD | 90.0 | 71.1 | 51.5 | 27.8 | NA | NA |
| GM | 7.0 | 1.3 | 0.9 | 1.0 | 3.6 | 11.6 |
| Median (IQR) | 6.6 (3.1–14.0) | 1.1 (0.4–2.9) | 0.4 (0.4–1.6) | 0.7 (0.7–1.0) | 2.7 (1.6–5.8) | 10.6 (5.6–22.2) |
| Tobacco smoke exposure (n=378) | ||||||
| n | 366 | 374 | 366 | 373 | 361 | 349 |
| % >LOD | 86.6 | 67.7 | 47.0 | 24.9 | NA | NA |
| GM | 6.8 | 1.3 | 0.9 | 0.9 | 3.5 | 11.6 |
| Median (IQR) | 7.0 (2.6–13.9) | 1.0 (0.4–2.9) | 0.4 (0.4–1.6) | 0.7 (0.7–0.7) | 2.6 (1.6–5.4) | 10.6 (5.0–22.3) |
| No tobacco smoke exposure (n=1981) | ||||||
| n | 1900 | 1968 | 1943 | 1932 | 1892 | 1812 |
| % >LOD | 90.6 | 71.8 | 52.4 | 28.4 | NA | NA |
| GM | 7.0 | 1.3 | 0.9 | 1.0 | 3.6 | 11.6 |
| Median (IQR) | 6.5 (3.2–14.0) | 1.1 (0.4–2.9) | 0.4 (0.4–1.6) | 0.7 (0.7–0.7) | 2.7 (1.6–5.8) | 10.6 (5.6–22.2) |
TCM: trichloromethane (chloroform); BDCM: bromodichloromethane; DBCM: dibromochloromethane; TBM: tribromomethane (bromoform); Br-THMs: sum of BDCM, DBCM and TBM; TTHMs: sum of TCM and Br-THMs; LOD: limit of detection; GM: geometric mean; IQR: interquartile range; NA: not applicable.