Children ride swings in a playground surrounded by smog in Lahore, Pakistan, Saturday, November 11, 2017. Smog has enveloped much of Pakistan, causing highway accidents and respiratory problems, and forcing many residents to stay home, officials said. (Photo by K.M. Chaudary/AP Photo)





A family wears masks to protect from the smog while waiting for transport on the roadside in Lahore, Pakistan, Saturday, November 11, 2017. (Photo by K.M. Chaudary/AP Photo)





Laborers work at a produce market covered in heavy smog in Lahore, Pakistan, Saturday, November 11, 2017. (Photo by K.M. Chaudary/AP Photo)





Pakistani police officers fire tear gas shell to disperse protesters during a clash in Islamabad, Pakistan, Saturday, November 25, 2017. Pakistani police have launched an operation to clear an intersection linking capital Islamabad with the garrison city of Rawalpindi where an Islamist group's supporters have camped out for the last 20 days. (Photo by Anjum Naveed/AP Photo)





People play cricket with the Hyperstar shopping mall and under construction buildings in the background, in Karachi, Pakistan November 20, 2017. (Photo by Akhtar Soomro/Reuters)





A Pakistani Sunni Muslim young girl takes part in a rally during celebrations marking Eid- e-Milad- un- Nabi, the birthday of Prophet Mohammad, in Quetta on December 1, 2017. (Photo by Banaras Khan/AFP Photo)





Fishermen carry a net as they catch small fish at the Arabian sea in Karachi, Pakistan, 06 February 2018. (Photo by Rehan Khan/EPA/EFE)





Younger students take an afternoon nap at the Al-Nadwa Madrassa in Murree, Pakistan, October 24, 2017. (Photo by Caren Firouz/Reuters)





Firefighters douse a fire on buses, which according to local media were set ablaze by people after a girl was killed due to over speeding, along a road in Karachi, Pakistan November 24, 2017. (Photo by Akhtar Soomro/Reuters)





Members of the anti narcotics force pose for a picture as drugs are burned during a ceremony in Islamabad, Pakistan on December 5, 2017. (Photo by Caren Firouz/Reuters)





Women prepare to light earthen lamps at the Bari Imam Shrine in Islamabad, Pakistan January 19, 2018. (Photo by Caren Firouz/Reuters)





A farm worker stacks cauliflower harvested on a farm on a truck outside Peshawar, Pakistan January 29, 2018. (Photo by Fayaz Aziz/Reuters)





Children play on a trampoline in a slum on the outskirts of Islamabad, Pakistan February 6, 2018. (Photo by Caren Firouz/Reuters)





Children stand on U.S. and Israeli flags during a protest following U.S. President Donald Trump's announcement that he has recognized Jerusalem as Israel's capital, in Islamabad, Pakistan December 7, 2017. (Photo by Caren Firouz/Reuters)





Relatives of poisoning victims pray at their graves in Basti Lashari, Pakistan, Wednesday, November 8, 2017. Pakistani police arrested a woman for allegedly plotting with her newly married niece to poison the niece's husband with tainted milk that also ended up killing 17 other in-laws in a remote village. (Photo by Iram Asim/AP Photo)





Villagers pray for poisoning victims during a condolence visit to the families in Basti Lashari, Pakistan, Wednesday, November 8, 2017. (Photo by Iram Asim/AP Photo)





Pakistani policemen gather under a tree during heavy rain near an accountability court where ousted Pakistani prime minister Nawaz Sharif appear before the corut to face corruption charges in Islamabad on November 15, 2017. In late July the Supreme Court made Sharif the 15th premier in Pakistan's 70-year history to be ousted before completing a full term, after a corruption investigation against him. (Photo by Aamir Qureshi/AFP Photo)





Pigeons fly at mid-section of a road surrounded by smog in Lahore, Pakistan, Sunday, November 12, 2017. Smog has enveloped much of Pakistan, causing highway accidents and respiratory problems, forcing many residents to stay home, officials said. (Photo by K.M. Chaudary/AP Photo)





A Pakistani vendor prepares peanuts for sale on a roadside in Peshawar, Pakistan, 01 January 2018. After a good raining season the sales of dry fruits flourish in the country. Tourists from all over Pakistan come to Peshawar to purchase dry fruits along with other items because of price differences between different parts of the country. (Photo by Bilawal Arbab/EPA/EFE)





A cyclist passes by the historical Badshahi Mosque while smog envelopes the area in Lahore, Pakistan, Sunday, November 5, 2017. Smog has enveloped much of Pakistan and neighboring India, causing highway accidents and respiratory problems, and forcing many residents to stay home, officials said. (Photo by K.M. Chaudary/AP Photo)





A horse cart and vehicles are driven on a road while fog envelopes the area in Peshawar, Pakistan, Sunday, November 5, 2017. (Photo by Muhammad Sajjad/AP Photo)





Pakistani Customs employee with fire torch stands amid burning piles of confiscated contraband and narcotics destroyed during a campaign marking International Customs Day in Karachi, Pakistan January 26, 2018. (Photo by Akhtar Soomro/Reuters)





Pakistani police officers beat a protester during a clash in Islamabad, Pakistan, Saturday, November 25, 2017. Pakistani police have launched an operation to clear an intersection linking capital Islamabad with the garrison city of Rawalpindi where an Islamist group's supporters have camped out for the last 20 days. (Photo by Anjum Naveed/AP Photo)





A Pakistani Hindu groom poses at a mass wedding ceremony in Karachi on January 28, 2018. The 10th Annual Hindu Combined Marriages Ceremony with 83 couples organised by the Pakistan Hindu Council. (Photo by Rizwan Tabassum/AFP Photo)





A Pakistani vendor carries baloons on a street amid heavy smog in Lahore on November 9, 2017. Flights were cancelled, school times pushed back and hospitals flooded as air pollution inundated Pakistan's second largest city Lahore November 8. The fast-developing country suffers from some of the worst air pollution in the world, thanks to its giant population navigating poorly maintained vehicles on its roads and unchecked industrial emissions along with seasonal crop burning. (Photo by Arif Ali/AFP Photo)





A street vendor selling balloons walks along a road shrouded in smog at night in Lahore, Pakistan on November 14, 2017. (Photo by Asad Zaidi/Bloomberg)