Home HealthTopics Health Centers Reference Library Research
Join us on Facebook Join us on Facebook Share on Facebook

Smoking and Tobacco

Smoke Presence in Lungs



How long does smoke last in your lungs?


I'm not sure how to answer this question. Smoke from all cigarettes contains numerous cancer-causing chemicals and other poisons that come from the tobacco itself, including tar and carbon monoxide. We can tell you how long Cotinine, the major metabolite of nicotine, may be detected in the body.

According to Dr. Mary Ellen Wewers, Professor & Associate Dean for Research Interim Director, Center for Health Outcomes, Policy and Evaluation Studies (HOPES), The Ohio State University, School of Public Health:

"Nicotine has a short half-life (2-4 hours) so often it is not detectable after 24 hours. Cotinine, its major metabolite, has a half-life of 16-19 hours so it usually is detectable for 4-7 days, depending upon amount of consumption."

The Centers for Disease Control have a National Biomonitoring Program (NBP) that measures people's exposure to toxic substances in the environment by measuring the substances or their metabolites in blood or urine. " Biomonitoring measurements are the most health-relevant assessments of exposure because they indicate the amount of the chemical that actually gets into people from all environmental sources combined (e.g., air, soil, water, dust, food).

The length of time smoke stays in your lungs definitely depends on how much tobacco is used, and how it is used (e.g. how many puffs, how deep are the inhalations, etc.). Cotinine can be detected in the saliva as well. Other sources for information on Cotinine are:

(See the CDC's Fourth National Report on Human Exposure to Environmental Chemicals)

Two good interactive websites to see the effects of smoking on the body are:

For more information:

Go to the Smoking and Tobacco health topic, where you can:

Response by:

Kathy Vesha, RN, BSN, MA
Kick It!
The James
The Ohio State University