What is the damage caused by sulphur dioxide (SO2) to human beings and the environment?

During the process of oxidation in the atmosphere this gas forms sulphates or salts that can be transported in the breathable particulate material (PM10) that in presence of humidity forms acids. Later these acids are an important part of the secondary particulate material or finest particulate material (PM2,5).
The exposure to sulphates and the exposure to acids derived from SO2 is extremely risky for people's health because these compounds enter the circulatory system directly through the airways.

Health effects

The SO2 is hygroscopic, when it is in the atmosphere it reacts with humidity and forms sulphuric and sulphurous aerosol acid that is later part of the so-called acid rain. The intensity in the formation of aerosols and the permanence of them in the atmosphere depend on the meteorological conditions and the quantity of catalytic impurities (substances that accelerate the processes) present in the air. But in general, the average time of permanence in the atmosphere is around 3-5 days, so it can be transported to greater distances.

The air pollution by SO2 has the following effects on human beings:

  • Corneal haze
  • Breathing difficulty
  • Airways inflammation
  • Eye irritation
  • Psychic alterations.
  • Pulmonary oedema.
  • Heart failure.
  • Circulatory collapse.

Sulphur dioxide is also associated with asthma, chronic bronchitis, morbidity and mortality increase in old people and infants.

Sulphur is a highly noxious venom for people's health, although we can be more resistant than other creatures that live with us. For example, the level of 0,3 µg per cubic metre of air implies a potential risk for human health, but for trees, 0,2 µg is extremely dangerous. Because of that, sulphur oxides (SOx) and sulphuric acid (H2SO4) are related with the damage and destruction of vegetation, soil deterioration, construction material and watercourses.