A general view shows smoke and volcanic ashes billowing from volcano Cotopaxi in Pedregal, Ecuador, late 07 October 2015. (Photo by Jose Jacome/EPA)

A woman smokes a mask bong on the final day of Hempfest, Seattle's annual gathering to promote the legalization of marijuana, on August 17, 2014. (Photo by Jordan Stead/Seattlepi.com)

A man smokes marijuana during a demonstration in support of the legalization of marijuana in Medellin, May 2, 2015. (Photo by Fredy Builes/Reuters)

A Muslim man carries holy incensed smoke through a pedestrian subway in Mumbai, India, May 13, 2016. (Photo by Danish Siddiqui/Reuters)

A reveller is seen smoking at the annual gay pride parade in Santo Domingo in the Dominican Republic July 03, 2016. (Photo by Ricardo Rojas/Reuters)

Two elderly men smoking pipes of opium on a terrace in Korea. (Photo by Bert Hardy/Picture Post/Getty Images). August 1950

Smoke billows from Jinnah International Airport in Karachi, Pakistan, June 9, 2014. (Photo by Athar Hussain/Reuters)

A man dressed as Hindu god Shiva, smokes during an annual Hindu religious festival locally known as Shyam Baba festival in Ajmer, in the desert Indian state of Rajasthan, April 12, 2015. (Photo by Himanshu Sharma/Reuters)