Speaking of China, pollution is so bad there that visibility is down to 50m. They declared an emergency over the whole country.
China chokes as it hits its worst air pollution levels of this year so far
mashable.com/2016/12/20/china-air-pollution-red-alerts-2016/
Dec 19, 2016 - Air quality in China has hit its worst of this year, with airborne pollutants exceeding 100 times the safe limit in many regions.