Taj Mahal is losing its sheen & colour because of DNA-sized carbon particles
Science

Taj Mahal is losing its sheen & colour because of DNA-sized carbon particles

As an immediate measure, scientists suggest that massive tree plantation nearby with frequent surface monitoring could help add to Taj Mahal's lifespan.

   
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Taj Mahal, Agra | Source: Pixabay

New Delhi: Nano-sized airborne particles of carbon are causing the marble surface of the Taj Mahal to slowly lose its sheen, according to a study into why the iconic monument is getting discoloured.

Scientists from the Archaeological Survey of India and the Ramakrishna Mission Vidyamandira in West Bengal have identified previously unrecognised airborne particles and their possible impact on the marble, using modern physico-chemical approaches.

The team showed that apart from particulate matter, which is micron-sized, the surface of the Taj Mahal was coated with carbon nano-tubes, graphene oxide and nano-carbon dots.

How small are these particles? For reference, a human hair on average is about 75 microns thick, while the DNA molecule is about 2.5 nanometre in diameter.

The nano-sized carbon deposits, which are more reactive than their micron-sized counterparts, are a result of pollutants from human activities, the study published in Heritage suggested.

How the particles cause damage

In the presence of air and sunlight, these carbon nano-particles generate several reactive oxygen species (ROS) — which lead to chemical reactions with deposits of algae, causing rapid degradation of the marble surface.

It also found that nitrogenous pollutants emitted by automobile exhausts and refineries produced reactive nitrogen species (RNS) on reacting with ROS.

These RNS, which are capable of destroying marble surfaces, are inflicting permanent damage to the Taj Mahal.

Clear strategy needed

“A clear strategy needs to be developed to prevent the accumulation of such reactive species on the surface of the monument vis-à-vis its surrounding environment,” the scientists wrote.

While maintaining a globally clean environment is the only way to ensure the protection of such monuments, the scientists suggested that as an immediate measure, a massive tree plantation in the nearby area with frequent surface monitoring, maintenance, and restoration of the affected surface of the monument could help add to its lifespan.

The Taj Mahal is India’s top revenue-generating monument. A total of 64.58 lakh people visited it in 2017-18, earning the government a revenue of Rs 56.83 crore.


Also read: The Taj Mahal is wasting away, and it may soon hit the point of no return