Nepalese Hindu priests perform rituals during Janai Purnima festival at Pashupatinath temple in Kathmandu, Nepal, Thursday, August 18, 2016. During this festival Hindus take holy baths and perform annual change of the Janai, a sacred cotton string worn around their chest or tied on the wrist, in the belief that it will protect and purify them. (Photo by Niranjan Shrestha/AP Photo)

People look at revellers (L) waiting to take part in a LGBT (lesbian, gay, bisexual and transgender) pride parade to mark Gaijatra Festival, also known as the festival of cows, in Kathmandu, Nepal, August 30, 2015. Hundreds of lesbians, gays, bisexuals and transvestites paraded through Nepal's capital Sunday to demand that rights for sexual minorities be included in the country's new constitution that is being finalized. (Photo by Navesh Chitrakar/Reuters)

A passenger (C) climbs through the window of an overcrowded bus as limited public transportation operates in the city during the ongoing fuel crisis in Kathmandu, Nepal October 9, 2015. Nepal is considering air-lifting fuel, possibly from Bangladesh, as supply routes from India stay blocked by protesters opposing its new constitution, a short-term solution ahead of a key festival even as the government talks to China for help. (Photo by Navesh Chitrakar/Reuters)

A police officer sprinkles colored powder onto a police dog at Nepal's Central Police Dog Training School during a dog worship day as part of the Diwali festival, also known as Tihar Festival, in Kathmandu, Nepal, 10 November 2015. The Tihar festival is the second major festival for Nepalese Hindus and this year is held from 10 November 2015. (Photo by Narendra Shrestha/EPA)

A devotee offers prayers to the setting sun during the "Chhat" festival at Bagmati river in Kathmandu, Nepal November 17, 2015. Hindus in Nepal celebrate "Chhat", a four-day festival that honours the sun god, by praying at sunrise and sunset, and seek blessings for one's family by giving offerings. (Photo by Navesh Chitrakar/Reuters)

People in Kathmandu joke that the face mask has now become part of the national dress – an indispensable accessory in an effort to protect themselves from the dust. Nepal has the worst air quality in the world, according to the Environmental Performance Index. (Photo by Pete Pattisson/The Guardian)

A woman with coloured powder smeared on her face smile as she celebrates Holi, the Festival of Colours, in Kathmandu, Nepal, March 22, 2016. (Photo by Navesh Chitrakar/Reuters)

A Nepalese Hindu devotee takes a holy bath as they mark the Mother's Day Festival at Matathirtha on the outskirts of Kathmandu on May 6, 2016. Nepalese Hindu devotees come from across the country to bathe, offer prayers and leave offerings at the Matathirtha Temple during the event, which honours mothers who have passed away. (Photo by Prakash Mathema/AFP Photo)