24 Sep Men with higher exposure to the substance DEHP, a so-called phthalate, have lower sperm motility and may therefore experience more. Oxygen is toxic to sperm and leads to decreased sperm function and death. This is in addition to the detrimental effects of air on sperm as the semen dries. 1 May Outside of the body, sperm may die quickly when they're exposed to the air. The length of time they stay alive has a lot to do with environmental.