The U.S. EPA estimates the cancer risk from wood smoke is twelve times greater than that from equal amounts of tobacco smoke. Materials on the low end of the energy scale such as wood and charcoal create the most pollution. Other low end recreational solid fuel sources are incense, candles, wax logs, charcole grills.

Many years ago a study was published stating that eating barbecued meat, grilled over coals or wood, is to your body like smoking a pack or more of cigarettes. Far more pleasant way to get those carcingens, IMHO, but we don't grill often.

Well GUEST, the smoke holes obviously vented both - the cooking fires and the burning/smoking of ceremonial Tobacco, sagebrush, sweetgrass, cedar and other sacred herbs which were (and still are) regularly used.

But you seemed to suggest that those natives were walking around rolling their own all day and puffing in the house. This has been shown not to be the case.