Marble marble cancer is cause due to chemical contents in the pollution mainly consisting of sulpher dioxide deposited on the marble surface absorbing oxygen and water vapor ,which would react with calcium in the marble stone forming surface disintegration and chaffing.
This is the yellowing of the Taj Mahal which is being caused by air pollution, especially sulphur dioxide. Combined with oxygen and moisture, sulphur dioxide settles on the surface of the tomb and corrodes the marble, forming a fungus that experts refer to as marble cancer