Till early 2000s, ASI used chemicals for conservation without any research on their effect on the monument
The marble used in the Taj Mahal has a unique translucent quality.It is also a little delicate. Soft marble was used on purpose to facilitate inlay work and carving.It is more vulnerable to cracks and breakage, and has to be handled with care. But back in the 1970s the Archeological Survey of India (asi) started to routinely use chemicals to clean the marble and sandstone in the Taj. A 2006 book, titled The Complete Taj Mahal, by art historian Ebba Koch says the asi had been using “ammonium and non-ionic detergents, hydrogen peroxide and triethanolamine with absorbent clay packs containing magnesium trisilicate, aluminium silicate… and with solvents like ethylene dichloride, benzene and triethanolamine” till 2002. Koch is a professor at the Institute of Art History in Vienna, Austria, and is considered a leading authority on Mughal architecture.
What is strange is that the asi decided to use the chemicals without carrying out any research on the effects of the chemicals even when conservationists have hinted that they might contribute to the yellowing of the stone.
In 1993,O P Agrawal, former director of the National Research Laboratory for Conservation of Cultural Property, wrote in a paper published in journal Puratattva, an annual bulletin of the Indian Archaeological Society, that not just pollution, but several other factors were also responsible for the discolouration of the monument and that controlling pollution alone would not help. The paper says that at least one of the chemicals used to clean the Taj, polymethyl methacrylate, was responsible for yellowing.It was used to wash the western garden-wall pavilion and east and west walls.The chemical is a preservative which is transparent while applying, but turns yellow later. Nilabh Sinha, head of the Material Heritage Division of non-profit Indian National Trust for Art and Cultural Heritage (intach), says polymethyl methacrylate may have been in vogue during the 1990s and early 2000s. asi officials claim they no more use harsh chemicals.asi, however ,is tight-lipped on why chemicals were used in the first place and when were they stopped. Officials are also silent over whether the chemicals deteriorated the monument .A 2008-09 booklet of asi’s science branch in Agra states the agency used chemicals to remove accretionary deposits on the marble in the main mausoleum, the main arches and the ornamental screen around the cenotaph. “In many cases, wax polish was applied on the cleaned surface, followed by burnishing, ”says the booklet titled Focus on Scientific Conservation of Cultural Heritage. The booklet, however, says asi now uses only glycerol, cellosolve and sodium bicarbonate. “We now use fuller’s earth pack ( multani mitti) that absorbs impurities from the surface. We only add glycerol, cellosolve and sodium bicarbonate in summers to ensure that the pack does not dry out fast. It takes at least 24 hours for proper cleaning, ”says an official in asi, Agra. “Such alkaline products are usually not harmful for stones, including marble,” says Satish Pandey, faculty at the Department of Conservation at the National Museum Institute of History of Art, Conservation and Museology, Delhi.The asi started using fuller’s earth in 1984,but it was mixed with “harmful ”aluminium silicate and magnesium trisilicate to remove greasy particulate matter, states the asi booklet (See ‘Efforts to keep the Taj’s glory, p38-39).
Conservationists stress the need for more research on the conservation material used and their long-term impact. “The marble stones used on the Taj Mahal are not uniformly white and have different shades. They may react differently to chemicals and this needs to be studied carefully,” says conservation architect Ratish Nanda, who heads the India operations of the Agha Khan
Trust for Art and Cultural Heritage. “Even the effect of water needs to be checked before used for cleaning, ”says Pandey .Amita Baig, who worked with the Taj Mahal Conservation Collaborative, says asi should also focus on red sandstone that is highly porous and prone to weathering.
Apart from chemicals, a big threat to the Taj’s conservation is the increasing footfall. With the growth in the tourism industry and the construction of Yamuna Expressway that connects Agra with Delhi, the number of tourists visiting the monument has increased manifold in recent years. When the Supreme Court passed its judgement in 1996,Taj Mahal received 0.2 million visitors a year.It touches 10 million a year today, which is double the number of tourists visiting the Vatican City. And while the Vatican is spread over an area of 44 hectares, the Taj Mahal complex is spread over just 16 hectares. “The number is astounding when one considers that the monument was built to handle only 40-50 people a day, ”says Baig.
According to the ticket sales data, the monument receives over 25,000 visitors on weekdays and over 40,000 during weekends. The actual figure will be higher because entry is free for children up to the age of 15 years. “The number increases when there is a centralised exam in the city as almost all examinees from outside the city come with family members who visit the Taj,” says Raj Kumar ,one of the asi officials responsible for managing tourists at the monument.The government earned over ` 20 crore through ticket sale in 2011,suggests asi data.
The action of tourists’ feet wears away the stone in the pavings, floors and terraces. The presence of crowd inside the tomb chamber shoots up the humidity level. Many succeed in writing their names on the walls with felt pens, necessitating the use of aggressive cleaning substances, says Koch in her book.asi officials admit the problem and say they are considering the recommendations submitted by the National Environmental Engineering Research Institute (neeri) in March this year on the Taj Mahal’s carrying capacity. Tourism and Culture minister Mukesh Sharma last month said the neeri recommendation to restrict visitors to the monument for two hours will be announced soon. But experts say the fundamental problem with the restoration work is that it lacks future planning. “We are only coping with today and not planning for tomorrow, ”warns Baig.
tourism industry and construction of expressway connecting Agra with Delhi have led to manifold rise in number