A woman smokes a cigarette next to man wearing a mask during lunch hour at the central business district in Singapore September 29, 2015. The 3-hour haze Pollutant Standards Index (PSI) reached a high of 173 at 8am on Tuesday, according to the National Environment Agency. Slash-and-burn agriculture in neighboring Indonesia has blanketed Singapore in a choking haze for weeks. (Photo by Edgar Su/Reuters)

Smokes rises from a fire as a Palestinian protester takes cover during clashes with Israeli troops near the Jewish settlement of Beit El, near the West Bank city of Ramallah October 9, 2015. (Photo by Mohamad Torokman/Reuters)

People are seen in the crowd as Serbian Emir Kusturica & The No Smoking Orchestra performs during the third day of the Mexican musicial festival Vive Latino, at the Foro Sol in Mexico City, on March 29, 2014. (Photo by Alfredo Estrella/AFP Photo)

Gunfire erupted at a Denver pot celebration Saturday, injuring two people and scattering a crowd of thousands who had gathered for the first 4/20 counterculture holiday since the state legalized marijuana... Photo: A woman smokes a large marijuana joint at the Vancouver Art Gallery during the annual 4/20 day, which promotes the use of marijuana, in Vancouver, British Columbia April 20, 2013. (Photo by Ben Nelms/Reuters)

A helicopter pours water over a wildfire with the Space Shuttle Endeavour seen through heavy smoke in the background April 27, 2011 in Cape Canaveral, Florida. (Photo by Roberto Gonzalez/Getty Images)

Emergency personnel respond to the scene of a train derailment in Santiago de Compostela, Spain, on Wednesday, July 24, 2013. A train derailed in northwestern Spain on Wednesday night, toppling passenger cars on their sides and leaving at least one torn open as smoke rose into the air. Dozens were feared dead, with possibly even more injured. (Photo by Antonio Hernandez/AP Photo/El correo Gallego)

Smoke rises during an explosion from an Israeli forces strike in Gaza City, Saturday, November 17, 2012. Israel bombarded the Hamas-ruled Gaza Strip with nearly 200 airstrikes early Saturday, the military said, widening a blistering assault on Gaza rocket operations by militants to include the prime minister's headquarters, a police compound and a vast network of smuggling tunnels. (Photo Hatem Moussa/AP Photo)

An employee in a bookshop adjusts packaged cigarettes which have to be sold in identical olive-brown packets bearing the same typeface and largely covered with graphic health warnings, with the same style of writing so the only identifier of a brand will be the name on the packet, in Sydney on December 1, 2012. A new world-first law forcing tobacco companies to sell cigarettes in identical packets came into effect Saturday in Australia in an effort to strip any glamour from smoking and prevent young people from taking up the habit. (Photo by William West/AFP Photo)