I am curious about VOG what is it? why is it dangerous? how does it form? how much is produced?
VOG is an abbreviation for volcanic smog, a specific form of natural air pollution. It is composed 
of Sulfur dioxide (SO2), Hydrogen Sulfide (H2S), and Carbon Dioxide (CO2) gasses when it is initially released from the volcano. When magma is exposed, it releases the previously mentioned dissolved gasses into the atmosphere. At which point the gasses mix with moisture and oxygen in the air aided by sunlight to create other gasses and aerosols, one example is Sulfuric Acid 
(H2SO4). Kilauea Releases anywhere from 1,000 to 2,500 TONS of SO2 per day. That gas then travels down to the south coast then right back north along the Kona side of the island, and then it blows off over the ocean (the picture on the left shows the VOG as red and yellow and the picture to the lower right shows the trade winds that move the VOG around the island). Although most people don't really get 
bothered by these gasses, for some it can cause problems because the aerosols tend to stay in your lungs. Results of exposure to VOG can be headaches, Breathing difficulties (including asthma), flu-like symptoms, and in severe cases problems with skin being irritated and itchy.
Sources
USGS
