Watch | After Taj Mahal, air pollution now takes sheen off Amritsar’s Golden Temple

The chronic air pollution blanketing much of northern India is now threatening the holiest shrine in the Sikh religion, making the once-gleaming walls of the Golden Temple dingy and dull.Thousands of Sikh devotees and tourists every day visit Amritsar, the main city in Punjab state , to see the 17th century shrine, surrounded by a moat known as the “pool of nectar,” or “Sarovar,” and housing Sikh holy book, the Guru Granth Sahib.While the city, located about 390 kilometres (240 miles) north of New Delhi, was named India's ninth most polluted by the World Health Organization in 2014, there is still no system in place for monitoring pollution. Toxic air has taken its toll on the temple's gold-plated domes and white-marble facade which are losing their lustre .There is little to be done short of replacing the 430-year-old temple's gold-plated walls - an expensive project already undertaken more than a century ago and then again in 1999.