As toxic particles enter the air, they make their way into your lungs every time you inhale. This decreases the level of oxygen your body is receiving and causes a buildup of carcinogenic toxins. In a 1989 study, researcher William Pryor of the Biodynamics Institute and the Pennington Biomedical Research Center found that wood smoke is active in the body 40 times longer than tobacco smoke. This means that campfire smoke is much more dangerous than second-hand tobacco smoke. Wood smoke inhalation is one of the primary causes for lung cancer found in non-smokers. It weakens the immune system and can cause or irritate asthma, lung disorders, and other respiratory diseases.