The four-day long Hindu festival of Chhath Puja began on Monday. The first day of the festival is dedicated to the Sun god and Chhathi Maiya and devotees observe the rituals of Nahay Khay. Devotees take bath in a river before eating on the first day. The festival is celebrated in Bihar, Jharkhand, Uttar Pradesh and Nepal and concludes on November 11, with Usha Arghya, when devotees will break their 36-hour ‘Nirjala’ (without water) fast. Every year, the focus during the festivals shifts towards the dangerous levels of pollution in the country’s rivers, including both the Ganga and Yamuna. In New Delhi, toxic foam can be seen floating on the surface of the Yamuna river, a result of industrial affluents being released in the waters.

Hindu women devotees pray after taking bath as part of the rituals of four days long ‘Chhath Puja’ celebrations, as toxic foam floats on the surface of polluted Yamuna river at Kalindi Kunj in New Delhi. 
Devotees arrive at the banks of River Ganga during the first day of four days long ‘Chhath Puja’ celebration, in Patna.
Hindu devotees offer prayers at the banks of River Ganga during the first day of four days long ‘Chhath Puja’ celebration, in Patna.
Hindu devotees offer prayers as part of the rituals of four days long ‘Chhath Puja’ celebrations, as toxic foam floats on the surface of polluted Yamuna river at Kalindi Kunj, in New Delhi.
Hindu devotees apply vermillion to each other while taking bath in the holy Ganga river on the occasion of the ‘Chhath Puja’ festival in Patna.
Devotees perform rituals and take dip in the river Ganga in Patna on the first day of Chhath Puja. 
Hindu devotees takes a bath as part of the rituals of four days long ‘Chhath Puja’ celebrations, as toxic foam floats on the surface of polluted Yamuna river at Kalindi Kunj, in New Delhi.