空气污染的天然来源 :许多不同污染物和化学物质的形成和散发来自地壳的天然过程 ,比如 ,火山喷发散发的颗粒物质和气态污染物像二氧化硫、硫化氢和甲烷。森林火灾也引发空气污染 ,散发烟雾、烟灰、未燃烧的碳氢化合物、一氧化碳、氧化氮以及灰尘。海啸喷发的颗粒 ,来自土壤的 Natural Sources of Air Pollution: The formation and distribution of many different pollutants and chemicals from natural processes in the crust, such as particulate matter and gaseous pollutants emanating from volcanic eruptions like sulfur dioxide, hydrogen sulfide and methane. Forest fires also cause air pollution, emitting fumes, soot, unburned hydrocarbons, carbon monoxide, nitrogen oxides and dust. Tsunami eruption particles, from the soil