🔗 Share this article

Intense atmospheric contamination in the nation's capital city of Delhi has caused the appearance of dark layers on the surfaces of the Red Fort, a new study finds.

Researchers discovered that these layers—formed due to reactions between contaminants and the red sandstone fort—were between 0.05mm and 0.5mm deep, and might deteriorate its intricate designs if no action implemented.

This research is the initial of its kind to thoroughly examine the consequences of environmental contamination on this ancient monument.

Conservationists have repeatedly alerted about the harmful effect of pollution on cultural sites in the city and several other states.

Previously, courts stated that the Taj Mahal—another historic site—had discolored due to pollutants, calling for immediate preservation actions.

The study on the Lal Qila, shared in a peer-reviewed journal in mid-2024, was conducted from 2021 and 2023 by experts from international institutions.

The iconic fort, constructed by ruler Shah Jahan, is among India's most prominent cultural landmarks.

India's inaugural Prime Minister Nehru raised the tricolor from the ramparts on August 16 1947, following freedom from colonial powers was announced. Ever since, heads of state have been presenting addresses on Independence Day from the fortress of the fort.

The team studied Delhi's air quality data from a three-year period. They then collected the sooty layer found on different areas of the monument and examined its content.

They determined that airborne particles and other contaminants in the atmosphere had resulted in the dark crust to develop on the monument's surfaces and also weakened other details such as vaults, arches, and intricate artwork.

The researchers also noted signs of peeling and erosion on the walls.

"Airborne pollutants are commonly accepted as key causes to the soiling of materials subjected to ambient air. This occurrence occurs when particulate matter accumulate over years, leading to noticeable blackening of these surfaces," the report notes.

The research recommends the prompt use of conservation strategies to preserve the monument.

"Appearance of a black crust is a progressive phenomenon that often begins with a slight sooty coating, which can be cleaned, especially in the initial phases," the report states.

It also mentions that protective coatings could be administered to vulnerable areas to prevent the development of black crusts.