4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is a tobacco-specific nitosamine metabolite that can help to distinguish active from passive tobacco exposure.
Half-life of NNAL in the urine: 10 to 16 days
Half-life of cotinine in the urine: 16 to 19 hours
Units of measurement for NNAL: pg/mL (ng/L)
Units of measurement for cotinine: ng/mL (µg/L)
Urine Cotinine |
Interpretation |
< 10 ng/mL |
nonsmoker or passive exposure or short-term abstinence |
10 to 100 |
probable passive exposure |
100 to 500 |
probable active smoker |
> 500 |
active smoker |
from Figure 1 page 205
Urine NNAL |
Interpretation |
< 3 pg.mL |
nonsmoker or passive exposure |
3 to 10 |
probable passive exposure |
10 to 47.3 |
uncertain (mix of active and passive smokers) |
47.4 to 100 |
probable active smoker |
> 100 pg/mL |
active smoker |
from Figure 2 page 205
Specialty: Toxicology, Emergency Medicine, Critical Care
ICD-10: ,