A significant fraction of troposphere aerosol originates from anthropogenic sources; it contains sulphate, ammonium, nitrate, sodium, chloride, trace elements, carbonaceous material, and water. Anthropogenic emissions have increased dramatically over the past century; this increase has affected human health, reduced visibility in urban regional areas, led to acid deposition and impacted on the Earth’s radiation balance (e.g. Seinfeld & Pandis, 2006).
