Severe air pollution in the Indian capital Delhi leads to a “black crust” on the walls of Red Fort, one of New York City’s most iconic Mughal monuments study Found it.
according to BBCThe researchers found that the crust formed by the chemical interaction between pollutants and the red sandstone fortress – with a thickness of 0.05mm to 0.5mm thick, if nothing is taken, could damage its complex engraving. The study was the first child to have an impact on air pollution on 17th-century monuments.
One of the world The most polluted Delhi cities often make headlines for their deteriorating air quality, especially in the winter.
Protectionists often warn of the harmful effects of pollution on the heritage structures of the capital and some other states.
In 2018, the Supreme Court stated that the Taj Mahal-the famous 17th-century mausoleum was turned yellow and green-brown from White Marble-Had, due to air and water pollution, and urged the Uttar Pradesh state government to take steps to protect it.
The study on the Red Fortress was published in the peer-reviewed Open Access Science Journal Heritage and was conducted between researchers in India and Italy from 2021 to 2023.
The Red Fortress, built by Mughal Emperor Shah Jahan, is one of Delhi’s most iconic heritage monuments and a popular tourist destination. The first Prime Minister of India, Jawaharlal Nehru, flew the national flag from the fort on August 16, 1947, the second day of declaring independence from Britain. Since then, the Prime Minister has been speaking from the walls of the fortress.
The researchers studied air quality data in Delhi between 2021 and 2023. Then they scraped off the black skin found on the various walls of the fortress and examined its composition.
They found that special substances and other pollutants in the air caused black sediments to form on the walls of the fortress and damaged other architectural elements such as vaults, arches and exquisite stone carvings. The researchers also found evidence of bubbles and peeling on the walls.
“PM2.5 and PM10 (the type of specific substances) are widely considered important factors in surfaces exposed to ambient air. This phenomenon occurs when a particular substance accumulates and accumulates over time, leaving discolored and black surfaces,” the study noted. The study recommends the implementation of protection strategies for protecting fortresses in a timely manner.
“The formation of black crust is a gradual phenomenon, usually starting with a thin layer of black or sediment that can be removed at least in the early stages,” the study noted.
It also says that stone protectors or sealants can be applied to affected heights to slow down or prevent the formation of black skin.
Posted at Dawn on September 17, 2025
