A blood test can be used to check for nicotine. The reasons for this can vary, but nicotine is an indication that a person smokes, which can have a large impact on a person's health. This information can be of interest to insurance agencies and potential employers. Also, a blood test for nicotine may be part of some smoking cessation programs. Urine or saliva testing could also be used to test for nicotine. The tests could test for cotinine instead of nicotine. Cotinine is produced by the body from the presence of nicotine. While some tests indicate levels of nicotine or cotinine present in the bloodstream, other tests indicate either a positive or negative, based on a predetermined level that triggers a positive result. There are several reasons why a blood test for nicotine can yield a false positive.
Diet
According to The American Academy of Insurance Medicine, the consumption of some foods before the blood test can elevate levels of substances that can cause false positives for nicotine. These foods include broccoli, cabbage, mustard, garlic, radishes, almonds and horseradish. Vegetarians can have elevated levels of a substance called thiocyanate, which can be a source of a false positive on a blood test for nicotine.
Environmental Exposure
People who have particular work environments can have elevated levels of thiocyanate, which can cause a false positive. The work environment is related to working with metal. The related occupations include electroplaters and people who refine precious metals.
Nicotine Products
Nicotine patches, nicotine gum and other nicotine products that are used in smoking cessation programs will yield positives on nicotine blood tests. These are not false positives, because nicotine is actually present in the bloodstream, but unless the testing facility is advised that the nicotine product is being used, there can be a false indication of smoking.
Lab Error
As with any human endeavor, there can be errors as a result of human error. Laboratory samples can be mislabeled. Results can be misinterpreted. Good labs have systems in place to minimize these human errors, but they can occur.
