What is 'secondhand smoke'?

What is 'secondhand smoke'?

Through the last thirty or forty years there have been several terms used for the smoke you breathe in when you've never lit a cigarette, either in your life or in your environment. Some people say environmental tobacco smoke, meaning someone around you is smoking and you're having to breathe in those fumes. But Secondhand Smoke is the term that you frequently hear right now. Passive smoking is another. It means that the smoke off the end of the cigarette that someone hasn't breathed into their mouth is filling the environment, disseminating and dispersing itself the way it does chemically, and can be breathed in from anyone who's within in that radius of air exchange. It also involves the gas breathed in through the cigarette into the mouth of the smoker through their lungs or mouth and then exhaled. That then joins the environment. So you're getting secondhand smoke from two ways: the unfiltered part that's coming off the burnt end of the cigarette which is the most dangerous, and the filtered part that's been though a human being and then comes back out, what comes out though the large airways and doesn't get stuck in the smoker's lungs. Secondhand Smoke is dangerous.