Table 5 Biomarker based prevalence of tobacco exposure at birth and at 4 years (N = 246), according to the previously established intervals.
Level of exposure (ng/mL) | Cord blood cotinine n (%) | Urinary cotinine at 4 years n (%) |
|---|---|---|
Non exposure <1 | 25 (10.2) | 4 (1.6) |
Low exposure 1–14 | 135 (54.9) | 157 (63.8) |
Medium exposure 14–50 | 23 (9.3) | 66 (26.8) |
High exposure 50–100 | 21 (8.5) | 16 (6.5) |
Very high exposure >100 | 42 (17.1) | 3 (1.2) |