First study to quantify link between carcinogen byproduct and lung cancer rates . Researchers tracked levels of byproduct ( NNAL ) using urine samples . If it were easy , 23 percent of adults in the United States would not smoke regularly . People with high levels of NNAL doubled their risk of developing lung cancer . Test could identify high - risk people , aid in early detection and treatment . Bottom line : This test could one day be used to identify smokers at high risk for lung cancer , but ' n't help against smoking 's other health hazards .
First study to quantify link between carcinogen byproduct and lung cancer rates . Researchers tracked levels of byproduct ( NNAL ) using urine samples . People with high levels of NNAL doubled their risk of developing lung cancer . Test could identify high - risk people , aid in early detection and treatment . Bottom line : This test could one day be used to identify smokers at high risk for lung cancer , but ' n't help against smoking 's other health hazards .