This study looks at what happens to the air in a special room after people use two kinds of tobacco: the **Ploom® heated tobacco product** (HTP) and regular **combustible cigarettes** (CC). **Heated tobacco products** are gadgets that warm tobacco without burning it. The study involves adults who smoke. Participants will visit the study center 4 times during the 6-week study. During these visits, they will try the Ploom device and spend time in an **environmental chamber** (EC), a closed room where air quality is measured. The goal is to compare air pollution from Ploom HTP with regular cigarettes. Participants are divided into two groups based on the type of cigarette they smoke: menthol or non-menthol. Both men and women between 22 and 65 years old can join. They must have smoked at least 5 cigarettes daily for a year. The study will monitor air quality, including harmful chemicals, in the EC.

• Study Duration: 6 weeks with 4 visits.
• Participants will try Ploom device and stay in the chamber for air tests.
• Health criteria: Participants must be regular smokers, healthy, and aged 22-65.