The release of Sulphur Dioxide (SO2) from a volcano is a sign that magma is relatively close to the surface.
If this gas is detected at a volcano that “is not erupting”, it could be a sign that it will erupt soon. However, La Soufriere is a volcano that is currently erupting effusively therefore this can explain the presence of the gas (if this is the case then the authorities need to say so).
How much Sulphur Dioxide is being released is also important to know. The challenge with this at La Soufriere is that Sulphur Dioxide dissolves easily in water and since there is subsurface water in the crater it may be difficult to determine how much of the gas is being released.
What persons need to also know is that when Sulphur Dioxide gets into the atmosphere it makes the surrounding air become hazardous. This can and will cause respiratory problems for persons.
This can affect persons living downwind from the summit of the volcano. This is another reason why persons MUST avoid venturing up the mountain.
Hope my little two cents contribution bring some clarity to my friends who were asking about this issue.
Facebook Post By: Randy Cornelius Boucher, Geography Teacher at the St Vincent Grammar School.
Sulfur Dioxide or Sulphur Dioxide is the chemical compound with the formula SO ₂. It is a toxic gas responsible for the smell of burnt matches. It is released naturally by volcanic activity and is produced as a by-product of copper extraction and the burning of fossil fuels contaminated with sulfur compounds. (Wikipedia)