Greening of Taj Mahal’s inlay work raises concerns
The root cause of the insect’s growth in the Yamuna River is attributed to pollution with a high concentration of phosphorus.
AGRA The greening of the inlay work, primarily on the northern wall of the Taj Mahal, has become a significant concern for the Archaeological Survey of India this year. Although the phenomenon has been observed on the white surface of the Taj Mahal since 2015, it was previously limited to the hot months of May and June. However, this year, green marks have appeared during October and November.
Raj Kumar Patel, the superintending archaeologist for the Archaeological Survey of India in Agra, said, “The greening of the white marble surface, especially on the inlay work of Taj Mahal walls, has been a recurring phenomenon for years. This year, it occurred in October, and despite remedial measures taken, the ‘attack’ by the ‘Goeldichironomus’ insect has reoccurred in November, which cannot go unnoticed.”
The cleaning process, conducted by the chemical branch of ASI, will be repeated, but repeated interventions are deemed unfavourable for the sensitive surface of a monument like the Taj Mahal, renowned for its beauty and charm. The ASI chief for the Agra circle pointed out ongoing vigilance and the search for an effective and stable solution to address the insect ‘Goeldichironomus,’ now seen in more months of the year.
Although the green marks left by the insect can be washed away with cotton dipped in distilled water, this greening is predominantly found on the northern wall of the Taj Mahal, facing the Yamuna River, believed to be on the portion that remains illuminated during night hours.
In 2016, scientists and faculty members at the School of Entomology at St John’s College in Agra identified the culprit behind the greening as the insect ‘Goeldichironomus,’ believed to thrive on the pollution of the Yamuna River, flowing behind the Taj Mahal’s northern side. Measures to control pollution in the river were suggested to mitigate the insect’s impact on the Taj Mahal.
Dr Girish Maheshwari, the head of the School of Entomology at St John’s College, explained that ‘Goeldichironomus’ serves as a bio-indicator of water quality, indicating localised water pollution. The high concentration of phosphorus in the water and sediments of the river enhances the reproductive productivity of the female insect, which can lay more than one thousand eggs.
Dr Maheshwari’s report in 2016 highlighted that the insect’s larval form feeds on algae and waste in the river, transforming into a pupa before emerging as an adult. These adults form massive swarms, attracted to the white stone of the Taj Mahal. While non-feeders, the chlorophyll within their bodies is transformed and discarded as excreta, staining the Taj Mahal walls green.
The root cause of the insect’s growth in the Yamuna River is attributed to pollution with a high concentration of phosphorus. Dr Maheshwari highlighted that improving the quantity and quality of the river could be an effective measure. The use of chemicals, if employed in large quantities, could be effective but risks destroying the ecosystem, impacting the food chain and negatively affecting the catchment area.
Dr Maheshwari also noted that ‘Goeldichironomus’ has caused damage to other tourist spots, including Monroe Lake in Florida (USA), where the U.S. government spent four million US dollars to control the insect. Similar damage occurred at Lake Suwa in Japan. Timely measures are crucial to prevent harm to iconic monuments like the Taj Mahal.
In 2016, Dr Maheshwari submitted his report to the ASI, which sent samples to three other destinations to determine the root cause of the greening of the Taj Mahal wall.