Pollution from open rubbish fires is turning India’s iconic white marble monument brown, leading to calls for better waste management.
Door-to-door waste collection in Agra, the city where the Taj Mahal is located, often bypasses poor neighbourhoods. As a result, many households burn food scraps, paper and other rubbish in the street.
A recent study by Sachchida Tripathi at the Indian Institute of Technology Kanpur and his colleagues found that waste burning in Agra deposits 150 milligrams of fine pollution particles per square metre of the Taj Mahal annually.
This may explain why other interventions to reduce discolouration have had little impact. In 1996, for example, India restricted vehicle access near the monument and took steps to reduce industrial emissions. Last year, the use of cow dung as a cooking fuel was banned. But still the marble continues to darken.
The study found that the impact of open rubbish on the Taj Mahal is 12 times that of dung cake burning, but didn’t compare it with other pollution sources.
Cleaners are using “mud packs” which draw out impurities to eliminate the marble’s brown stains. But the Archaeological Survey of India – the country’s archaeological research body – recently warned that this could permanently alter the colour, texture and shine of the surface.
Preventing staining in the first place is a better strategy, says Tripathi. Introducing low-emission household incinerators and organising regular waste pick-ups are possible solutions, he says.
These interventions could also significantly improve public health. The study estimated that inhalation of fine particles from rubbish fires causes 713 premature deaths in Agra each year, based on the established link between air pollution and cardiovascular and respiratory disease.
“When you live in a developed country, you don’t think about air pollution too much because you look outside the window and it’s clear,” says Bin Jalaludin at the University of New South Wales in Australia. “But it’s increasingly becoming a problem in megacities in India and China where there is a constant haze, so governments are taking notice.”
Journal reference: Environmental Research Letters, DOI: 10.1088/1748-9326/11/10/104009