How does marble’s chemical composition react to urban pollution in sculptures?
Marble, primarily composed of calcium carbonate (CaCO₃), is highly susceptible to urban pollution due to its chemical properties. When exposed to acidic pollutants like sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) in the air, marble undergoes a reaction that forms soluble salts such as calcium sulfate (CaSO₄). This process, accelerated by acid rain, leads to surface erosion, loss of detail, and structural weakening in sculptures. Over time, the once-smooth surfaces become pitted and discolored. Additionally, particulate matter in polluted air can embed into the marble, further accelerating deterioration. Understanding these reactions helps in preserving historical and artistic marble works in urban environments.
