This might be a new word for you: vog.
Vog is volcanic smog, produced when sulfuric acid and other gases emitted by volcanoes mixes with oxygen and water vapor in the presence of sunlight. It can cause or aggravate respiratory problems among humans and damage plants. Below is an image showing this noxious gas around Hawaii, where Kilauea, which has been erupting continuously since 1983, produces large quantities of vog.
The image is from NASA Earth Observatory.
USGS page on vog, from the Hawaiian Volcano Observatory.
Grace and Peace
P.S. Kilauea releases about 1000 tons of sulfur dioxide into the atmosphere per day. This is small compared to the 200,000 tons of sulfur dioxide that is released into the atmosphere per day through burning of fossil fuels and other industrial processes.