'Third-hand' smoke lingers in movie theaters, study finds

Movie theaters, along with hotels, rental car companies, and other industries, have implemented strict no-smoking policies to prevent "third-hand" smoke contamination, where potentially harmful residue from cigarettes lingers on objects. But a new study finds that smokers who enter a non-smoking movie theater are capable of bringing in a large amount of cigarette residue that can affect air quality for extended periods of time. Researchers assessed the air quality of theaters and observed a spike in the concentration of chemicals found in cigarette smoke after moviegoers walked in for screenings. The scientists found that the gas emissions were akin to being exposed to secondhand smoke from 1 to 10 cigarettes for an hour, and nicotine was the most abundant substance they found. Movie theaters are usually well-ventilated, the authors write, suggesting that other public places that are poorly ventilated have a higher risk of transmitting third-hand smoke.