Why does Mathura refinery pose problems to the Taj Mahal?

Explanation

Mathura refinery releases many air polluntants such as sulphur dioxide. So reacts with water in the atmosphere to forms sulphuric acid. This sulphuric acid is washed away into the soil by rain (acid rainfall). This acid errodes the stone, surface of buildings, affects salmon reproduction, brick works, etc. Thus posing a great threat to Taj Mahal as they can destroy the marble quality and its colour, etc.