Is pollution the culprit ?

New Delhi, May 14: A parliamentary committee said it was worried that the Taj Mahal was turning yellow.

In its report tabled today in Parliament, the all-party committee on transport, tourism and culture expressed “concern” that “the world famous monument at Agra is becoming yellowish due to suspended particulate matter”.

The committee headed by CPM member Sitaram Yechury has advised caution during conservation activity at the Taj to “retain the original glory of the shimmering white marble”.

The committee noted that the Air Pollution Monitoring Laboratory at Agra had found the level of air pollutants — sulphur dioxide and nitrus oxide — generally within permissible limits. But suspended particulate matter was “always at a very high level except during the rainy season”.

The deposition of suspended particulate matter imparted a “yellow tinge” to the marble surface, the report said. It said a non-corrosive and non-abrasive “clay pack treatment” is carried out to remove the deposits.

The laboratory keeps tabs on the ambient air quality in and around the Taj to study the impact of pollutants on the monument and draw up conservation measures.

Environmental experts said dust particles in the air around the Taj would need to be analysed before any conclusions can be drawn over whether they are contributing to any yellow hue on the stone.

Suspended particulate matter could be inert dust that is accumulating but could be brushed off, or it could contain chemicals, said Satish Wate, head of the environmental impact division at the National Environmental Engineering Research Institute in Nagpur.

He said inert dust particles — such as sand particles — were unlikely to cause any change in colour. Only particles containing chemicals that can interact with the stone will be able to alter its colour, one scientist said.

The Central Pollution Control Board has been monitoring the air around the Taj, but its officials said they would like to study the parliamentary committee report before commenting on it.