Under certain circumstances, chemical reactions occur in which this dioxide can be transformed into trioxide.
Sulfur dioxide in high concentrations can be an irritating gas that causes alterations in the eyes and respiratory tract. The two are issued together and the proportion of the second is from 1% to 5% of the total. The emission of trioxide is much higher quantitatively than that of dioxide. The most important sulfur oxides in terms of air pollution are sulfur dioxide, SO2 and sulfur trioxide, SO3. The main sources are thermal power plants, various industrial processes, automobile traffic and certain heaters.
Within sulfur compounds, oxides originate from fossil fuel combustions that contain sulfur, such as coal, oil and some derivatives. In the case of gases, the units are the parts per million. The units with which the particles are measured are micrograms of contaminant per cubic meter.
