Third-hand Smoke (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption In tests at Berkeley Lab of celluose surfaces contaminated with nicotine residues from third-hand smoke, levels of newly formed TSNAs rose 10 times following a three hour exposure to nitrous acid. TSNAs are potent carcinogens. Credit Photo by Roy Kaltschmidt, Berkeley Lab Public Affairs Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.