| |
| | Secondhand Smoke: Questions and Answers - National Cancer Institute |
 | | Secondhand smoke, also called environmental tobacco smoke (ETS), is the combination of smoke emitted from the burning end of a cigarette, cigar, or pipe, and smoke exhaled by the smoker (see Question 1). |
 | | Because it is a complex mixture of chemicals, measuring secondhand smoke exposure is difficult and is usually determined by testing blood, saliva, or urine for the presence of nicotine, particles inhaled from indoor air, or cotinine (the primary product resulting from the breakdown of nicotine in the body) (1, 3). |
 | | Secondhand smoke exposure is a known risk factor for lung cancer (1, 3, 4, 6, 7). |
| www.cancer.gov /cancertopics/factsheet/Tobacco/ETS (1691 words) |
|