Why are buildings made from limestone affected by burning fossil fuels containing sulfur?

Answer 1

When the sulphur from these fuels burns in the oxygen from the atmosphere sulphur dioxide and sulphur trioxide are produced. These gases combine with water to form sulphurous and sulphuric acid respectively. Limestone consists largely of the carbonates of magnesium and calcium. Both of these acids react with the carbonates to form sulphites and sulphates that are moderately soluble in water. So although the original limestone in the buildings is hardly soluble in water at all and will last a very long time, these sulphites and sulphates are much more soluble and will wash away very quickly. In short, the sulphur from the burnt fuel combines with the limestone and washes away leaving the limestone diminished in size and strength.