The U.S. Geological Survey defines vog as:
Noxious sulfur dioxide gas and other pollutants emitted from Kilauea Volcano on the Island of Hawai`i react with oxygen and atmospheric moisture to produce volcanic smog (vog) and acid rain.
They also list some of the physical complaints directly related to vog exposure. Headaches, breathing difficulties, increased susceptibility to respiratory ailments, watery eyes, sore throat, flu-like symptoms, and a general lack of energy.
The vog mainly hangs out on the Big Island, but for the past month or so, the entire island chain has been experiencing heavy vog. A couple of weeks ago, the mountains were barely visable on my drive into work and this was first thing in the morning. Usually the vog does not become thick until later in the day. This afternoon when driving home, the sky was the strangest color blue. If I didn't live here, I would not have known that there were mountains nearby.
The air has been so thick with this vog for days and days now. My chest feels like there is a brick on it. Everyone at work is getting sick. I am positive the vog had a direct impact on my getting sick last weekend. I had every symptom above and still am having a difficult time breathing. I rarely use my inhaler but recently it has been my best friend. I don't think I could ever live on the Big Island.